Atlas of Emergency Neurosurgery
Atlas of Emergency Neurosurgery Atlas of Emergency Neurosurgery Jam ie S. Ullm an, MD, FAANS, FACS Associate Professo
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Atlas of Emergency Neurosurgery
Atlas of Emergency Neurosurgery
Jam ie S. Ullm an, MD, FAANS, FACS Associate Professor, Dep ar t m en t of Neu rosurger y Hofst ra Nor th Sh ore-LIJ Sch ool of Medicin e Director of Neurot rau m a Nor th Sh ore Un iversit y Hospit al Man h asset , New York P.B. Raksin, MD, FAANS Assist an t Professor, Depar t m en t of Neurosu rger y Ru sh Un iversit y Medical Cen ter Director, Neurosu rger y ICU Ch ief, Sect ion Neu rot raum a & Neurocrit ical Care Joh n H. St roger Jr Hospit al of Cook Coun t y (form erly Cook Cou n t y Hospit al) Ch icago, Illin ois Medical Illustrato r: Jennifer Pryll
Th iem e New York · St u t tgar t · Deh li · Rio de Jan eiro
Execut ive Editor: Tim othy Hiscock Man aging Editor: Elizabeth Palu m bo Director, Editorial Ser vices: Mar y Jo Casey Editorial Assist an t: Haley Paskalides Product ion Editor: Heidi Grauel In ternat ion al Product ion Director: An dreas Sch aber t Vice Presiden t , Editorial an d E-Produ ct Developm en t: Vera Spilln er In ternat ion al Market ing Director: Fion a Hen derson In ternat ion al Sales Director: Louisa Turrell Director of Sales, Nor th Am erica: Mike Rosem an Sen ior Vice Presiden t an d Ch ief Operat ing O cer: Sarah Van derbilt Presiden t: Brian D. Scan lan Prin ter: Asia Paci c O set Library o f Co ngress Catalo ging-in-Publicatio n Data Atlas of em ergency neurosurger y / [edited by] Jam ie Ullm an , P.B. Raksin . p. ; cm . In clu des bibliograph ical referen ces an d in dex. ISBN 978-1-60406-368-4 — ISBN 978-1-60406-369-1 (eISBN) I. Ullm an , Jam ie, editor. II. Raksin , P. B. (Pat ricia B.), editor. [DNLM: 1. Em ergen cies—Atlases. 2. Neurosurgical Procedu res—m eth ods—Atlases. 3. Cen t ral Ner vou s System —surger y—Atlases. 4. Cen t ral Ner vous System Diseases—surger y—Atlases. 5. Cran iocerebral Traum a—surger y—Atlases. 6. Spin al Cord Injuries—surger y—Atlases. 7. Spin al Injuries—surger y—Atlases. W L 17] RD593 617.4’8—dc23 2015005194 © 2015 Th iem e Medical Publish ers, In c. Th iem e Pu blish ers New York 333 Seven th Aven u e, New York, NY 10001 USA, 1-800-782-3488 custom erser vice@th iem e.com Th iem e Pu blish ers St u t tgart Rü digerst rasse 14, 70469 St ut tgar t , Germ any, +49 [0]711 8931 421 custom erser vice@th iem e.de Th iem e Pu blish ers Delh i A-12, Secon d Floor, Sector -2, NOIDA -201301, Ut t ar Prad esh , In d ia, +91 120 45 566 00 custom erser vice@th iem e.in Th iem e Pu blish ers Rio d e Jan eiro, Th iem e Pu blicações Ltda. Argen t in a Bu ilding 16th oor, Ala A, 228 Praia do Bot afogo Rio de Jan eiro 22250-040 Brazil, +55 21 3736-3631 Prin ted in Ch in a 54321 ISBN 978-1-60406-368-4 Also available as an e-book: eISBN 978-1-60406-369-1 Im po rtant note : Medicin e is an ever-ch anging scien ce u n dergoing con t in u al d evelop m en t . Research an d clin ical experien ce are con t in u ally exp an ding our know ledge, in par t icular our kn ow ledge of proper t reat m en t an d drug th erapy. Insofar as this book m en t ion s any dosage or ap p licat ion , readers m ay rest assu red th at th e au th ors, editors, an d p u blish ers h ave m ade ever y e or t to en su re th at su ch referen ces are in accordan ce w ith the state o f know ledge at the tim e o f pro ductio n o f the bo o k. Never theless, th is does n ot involve, im ply, or express any guaran tee or respon sibilit y on th e par t of the publish ers in respect to any dosage inst ruct ion s an d form s of applicat ion s st ated in th e book. Every use r is requested to exam ine carefully th e m an ufact urers’ lea et s accom panying each drug and to ch eck, if n ecessar y in con sult at ion w ith a physician or specialist , w h eth er th e dosage sch edules m en t ioned th erein or th e cont rain dicat ions st ated by th e m an ufact urers di er from th e st atem en t s m ade in th e presen t book. Such exam in at ion is par t icularly im port an t w ith drugs th at are eith er rarely used or h ave been new ly released on th e m arket . Ever y dosage sch edule or ever y form of applicat ion used is en t irely at th e user’s ow n risk an d respon sibilit y. Th e auth ors an d publishers request ever y user to repor t to th e publish ers any discrepan cies or in accuracies n ot iced. If errors in th is w ork are foun d after publicat ion , errat a w ill be posted at w w w.th iem e. com on th e product descript ion page. Som e of th e product n am es, paten t s, and registered design s referred to in th is book are in fact registered t radem arks or propriet ar y n am es even th ough speci c referen ce to th is fact is n ot alw ays m ade in th e text . Th erefore, th e appearan ce of a n am e w ith out design at ion as proprietar y is not to be con st ru ed as a represen t at ion by th e publish er th at it is in th e public dom ain .
Th is book, in clu ding all par t s th ereof, is legally protected by copyrigh t . Any u se, exp loit at ion , or com m ercializat ion ou t side th e n arrow lim it s set by copyrigh t legislat ion , w ith¬out th e publish er’s con sen t , is illegal an d liable to prosecut ion . Th is applies in par t icular to ph otost at reproduct ion , copying, m im eograph ing, preparat ion of m icro lm s, an d elect ron ic dat a processing and storage.
Contents
Fo rew o rd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xi Ackno w ledgm en ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii Co ntributo rs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv I Cerebral Traum a and Stro ke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Chapter 1: Surger y for Epidural an d Subdural Hem atom as Shelly D. Tim m ons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Chapter 2: Ch ron ic Subdural Hem atom as Branko Skovrlj, Jonathan Rasouli, A. Stew art Levy, P. B. Rak sin, and Jam ie S. Ullm an . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Chapter 3: Surger y for Cerebral Con t u sion s of th e Fron t al an d Tem p oral Lobes, In clu ding Lobar Resect ion s Pal S. Randhaw a and Craig Rabb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33 Chapter 4: Decom pressive Cran iectom y for In t racran ial Hyper ten sion an d St roke, In clu ding Bon e Flap Storage in Abdom in al Fat Layer Roberto Rey-Dios and Dom enic P. Esposito . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 Chapter 5: Surger y for Cerebellar St roke an d Suboccipit al Traum a Faiz U. Ahm ad and Ross Bullock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73 Chapter 6: Elevat ion of Depressed Skull Fract ures Anand Veeravagu, Bow en Jiang, and Odette A. Harris . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90 Chapter 7: Invasive Neurom on itoring Tech n iques Mathieu Laroche, Michael C. Huang, and Geo rey T. Manley . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Chapter 8: Surgical Debridem en t of Pen et rat ing Injuries Roland A. Torres and P. B. Rak sin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 Chapter 9: Man agem en t of Traum at ic Neurovascular Injuries Boyd F. Richards and Mark R. Harrigan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Chapter 10: Man agem en t of Ven ou s Sin u s Inju ries Laurence Davidson and Rocco A. Arm onda . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
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Contents
II Spin al Em ergen cy Pro cedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Chapter 11: Applicat ion of Closed Spin al Tract ion Nirit W eiss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 Chapter 12: Em ergen cy Man agem en t of Odon toid Fract ures Sanjay Yadla, Benjam in M. Zussm an, and Jam es S. Harrop . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 Chapter 13: Cer vical Burst Fract ures Teresa S. Purzner, Jam es G. Purzner, and Michael G. Fehlings . . . . . . . . . . . . . . . . . . . . . . . . . . 197 Chapter 14: Cer vical Facet Dislocat ion Daniel Resnick and Casey Madura . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 Chapter 15: Classi cat ion an d Treat m en t of Th oracic Fract ures Joseph Hsieh, Doniel Drazin, Michael Turner, Ali Shirzadi, Kee Kim , and J. Pat rick Johnson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 Chapter 16: Th oracolu m bar Fract ures Michael Y. W ang and Brian Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 Chapter 17: Spin al Epidu ral Com pression Asha Iyer and Arthur Jenkins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 Chapter 18: Treat m en t of Acute Cauda Equin a Syn drom e Harel Deutsch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 III No ntraum atic Em ergencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311 Chapter 19: Rem oval of Spon tan eous In t racerebral Hem orrh ages Just in Mascitelli, Yakov Gologorsk y, and Joshua Bederson . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312 Chapter 20: Su rger y for Acute In t racran ial In fect ion P. B. Rak sin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330 Chapter 21: Ven t ricular Sh un t Malfun ct ion Sergey Abeshaus, Sam uel R. Brow d, and Richard G. Ellenbogen . . . . . . . . . . . . . . . . . . . . . . . . 349 Chapter 22: Pit uit ar y Apoplexy Kalm on D. Post and Soriaya Mot ivala . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370 IV Em ergen cy Operatio ns in Co m bat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385 Chapter 23: Com bat Cran ial Operat ion s Leon E. Moores . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386 Chapter 24: Com bat-Associated Pen et rat ing Spin e Injur y Corey M. Mossop, Christopher J. Neal, Michael K. Rosner, and Paul Klim o Jr. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 V Reco nstructive Surgery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411 Chapter 25: Replacem en t of Cran ial Bon e Flap Jam ie S. Ullm an . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412 Chapter 26: Tech n iques of Alloplast ic Cran ioplast y Erin N. Kiehna and John A. Jane Jr. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424 Chapter 27: Su rger y for Fron t al Sin u s Injuries Abilash Haridas and Peter J. Taub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 444
Conte nts
VI Special Co nsideratio ns in Pediatric Em ergency Neuro surgery . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457 Chapter 28: Sp ecial Con siderat ion s in th e Su rgical Man agem en t of Pediat ric Trau m at ic Brain Inju r y Anthony Figaji and P. David Adelson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .458 Chapter 29: Sp ecial Con siderat ion s in Pediat ric Cer vical Sp in e Inju r y Paul Klim o Jr., Nelson Ast ur Neto, W illiam C. W arner Jr., and Michael S. Muhlbauer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .470 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 491
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Continuing Medical Education Credit Information and Objectives
Objectives 1. 2. 3. 4.
Iden t ify n eurosurgical con dit ion s w h ich require em ergen t or urgen t in ter ven t ion Evaluate th e various opt ion s for m an aging spin e t raum a in th e cer vical, th oracic, an d th oracolum bar region s. Apply provided tech n iques w h en perform ing urgen t in ter ven t ion s for th e brain an d spin e Recogn ize key issues of applying brain an d spin al t rau m a surgical tech n iques to m ilitar y an d pediat ric populat ion s.
Accreditation and Designation Th e AANS is accredited by th e Accredit at ion Coun cil for Con t in uing Medical Edu cat ion (ACCME) to provide con t in uing m edical edu cat ion for physician s. Th e AANS design ates th is en during m aterial for a m a xim um of 15 AMA PRA Category 1 credit sTM. Physician s should claim on ly th e credit s com m en surate w ith th e exten t of th eir part icipat ion in th e act ivit y. Meth od of p hysician p ar t icip at ion in th e learn ing process for th is text book: Th e Hom e St u dy Exam in at ion is on lin e on th e AANS w ebsite at: h t t p ://w w w.aan s.org/ed u cat ion /books/aon em ergen cy.asp Est im ated t im e to com plete th is act ivit y varies by learn er, an d act ivit y equaled up to 15 AMA PRA Category 1 credits TM.
Release and Termination Dates Origin al Release Date: 05/2/2015 CME Term in at ion Date: 05/2/2018
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Disclosure Information
Th e AANS con t rols th e con tent an d product ion of th is CME act ivit y an d at tem pts to en sure th e presen tat ion of balan ced, object ive in form at ion . In accordan ce w ith th e St an dards for Com m ercial Support est ablish ed by th e Accredit at ion Cou n cil for Con t in u ing Med ical Edu cat ion , au th ors, p lan n ing com m it tee m em bers, sta , an d any oth ers involved in plan n ing in edu cat ion con ten t an d th e sign i can t oth ers of th ose m en t ion ed m u st disclose any relat ion sh ip th ey or th eir co-au th ors h ave w ith com m ercial in terest s w h ich m ay be related to th eir con ten t . Th e ACCME de n es, “relevan t n an cial relat ion sh ip s” as n an cial relat ion sh ip s in any am ou n t occurring w ith in th e past 12 m on th s th at create a con ict of in terest . Tho se (and the signi cant others o f tho se m entio ne d) w ho have disclo sed a relatio nship* w ith co m m ercial interests are listed below .
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Aqueduct Neurosciences, Inc., Navisonics, Inc.
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Codm an Johnson & Johnson, Integra Neurosciences
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Shelly D. Tim mons, MD, PhD, FAANS
AO Neuro Resident Neurotrauma Course
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Michael Turner, Md, PhD
Acuit y Surgical
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Depuy Spine Aesculap Spine, Globus Medical Neuro Consulting, LLC
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Disclosure Information *Relat ionship refers to receipt of royalt ies, consultantship, funding by research grant, receiving honoraria for educat ional services elsew here, or any other relat ionship to a com m ercial interest that provides su cient reason for disclosure. Tho se (and the signi cant others o f tho se m entio ne d) w ho have repo rted they do not have any relatio nship w ith co m m ercial interests: Nam e : Sergey Abesh au s, MD P. David Adelson , MD, FAANS Faiz U. Ah m ad, MD Rocco A. Arm on da, MD, FAANS Nelson Ast u r, MD Josh u a B. Bederson , MD, FAANS M. Ross Bu llock, MD, Ph D Lau ren ce Davidson , MD, FAANS Don iel Gabriel Drazin , MD Yakov Gologorsky, MD Mark R. Harrigan , MD, FAANS Odet te Alth ea Harris, MD, MPH, FAANS Brian Jam es Hood, MD Josep h C. Hsieh , MD Mich ael C. Hu ang, MD Ash a Mu th uram an Iyer, MD Joh n A. Jan e, Jr., MD, FAANS Ar th u r L. Jen kin s III, MD, FAANS Bow en Jiang, MD J. Pat rick Joh n son , MD, FAANS Erin Kieh n a, MD Pau l Klim o, Jr., MD, FAANS Math ieu Laroch e, MD An d rew Stew ard Levy, MD Ju st in Robert Mascitelli, MD #
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Educat ion al Con ten t Plan n ers.
Leon E. Moores, MD, FAANS Corey Mich ael Mossop Soriaya Mot ivala, MD Mich ael S. Mu h lbau er, MD, FAANS Ch ristoph er J. Neal, MD FAANS Kalm on D. Post , MD, FAANS Craig H. Rabb, MD, FAANS Pat ricia B. Raksin , MD, FAANS# Pal Ran dh aw a, MD Jon ath an Rasou li, MD Dan iel K. Resn ick, MD, FAANS Roberto Rey-Dios, MD Boyd Rich ards, DO Mich ael K. Rosn er, MD, FAANS Ali Sh irzadi, MD Bran ko Skor vlj, MD Peter J. Tau b, MD, FACS, FAAP Rolan d A. Torres, MD, FAANS Jam ie S. Ullm an , MD, FAANS# An an d Veeravagu , MD William C. Warn er, Jr., MD Nirit Weiss, MD, FAANS Sanjay Yadla, MD Benjam in M. Zussm an , MD Casey Madu ra, MD
Forew ord
Sim plicit y is the ult im ate sophist icat ion. – Leonardo da Vinci, circa 1519 Th is at las ed ited by Drs. Ullm an an d Raksin is clearly a ver y valu able con t r ibu t ion to t h e n eu rosu rgical literat u re an d m ay be best d escr ibed as a qu ick referen ce at las. Bot h of t h e ed itors are exp er ien ced n eu rosu rgeon s w h o h ave h ad d ecad es of exp er ien ce in t reat ing p at ien t s w it h h ead an d sp in al inju r y. In t h is volu m e, t h ey h ave brough t toget h er m any exp er t s in th e eld to d escr ibe t h eir ap p roach to t h e sp ect r u m of t rau m at ic d isord ers t h at a ict t h e brain an d sp in e. Th e illust ration s are m agn i cen t an d th e text is direct an d easy to follow. Th is st yle ensures that this book w ill be a valu-
able guide for both residen ts as w ell as for m ore experien ced neurosurgeons. It w ill ser ve as a quick referen ce before one em barks on treating a patient w ith a traum atic neurosurgical disorder, or in preparing to take an exam ination. Alth ough th ere are oth er texts th at deal w ith n eurot raum a, n on e of th em are as digest ible as th is on e. I could w ax eloquen t on th e m any m erit s of th is book. I don’t n eed to. As you sim ply ip th rough its pages, you w ill see for yourself th at th is is a book w or th h aving—n ot ju st to disp lay on you r booksh elf, bu t to keep h an dy an d to u se on an ever yday basis. You w ill h ave n o t rouble pu t t ing it to good use. Raj K. Narayan, MD, FACS, FAANS Professor an d Ch airm an Dep ar t m en t of Neu rosu rger y Hofst ra Nor th Sh ore LIJ Sch ool of Medicin e an d Director, Cu sh ing Neu roscien ce In st it u te Man h asset , New York
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Acknow ledgments
We w ould like to ackn ow ledge an d th an k th e auth ors—kin d colleagues, m en tors, an d dedicated residen t s an d fellow s—for len ding th eir ext raordin ar y expert ise an d experien ce to th is project . We w ou ld like to th an k Dr. Mark Lin skey, past ch air of th e AANS Publicat ion s Com m it tee, for support ing th e con cept of th is atlas, an d Dr. Jam es Rutka, th en AANS secretar y, for ch am p ion ing th is atlas to th e AANS Board of Directors. We are grateful to th e AANS for it s gen erous gran t—m atch ed by Th iem e Publish ers (to w h om w e are also gratefu l)—to fu n d th e illu st rat ion s. Th an ks also go to th e Execut ive Com m it tee of th e AANS/CNS Sect ion on Neu rot rau m a an d Crit ical Care for its su p port an d from w h ich m any of th e au th ors w ere selected . We are gratefu l to Dr. Mich ael Feh lings for h is review an d cou n sel regarding th e spin e top ics. We ackn ow ledge an d th an k th e Th iem e ed itorial sta , past an d presen t , for th eir h ard w ork an d d edicat ion to th is project . Illu st rat ion s form th e backbon e of th is book an d, so, a sp ecial th ank you goes to Jen n ifer Pr yll, our n e illust rator, for h er t ireless e ort s in producing h igh -qualit y art w ork. Ms. Pr yll dem on st rated an ext raordin ar y level of at ten t ion to detail an d resp on siven ess to th e editors an d au th ors.
I (JSU) w an t to, p erson ally, dedicate th is book to m y daugh ter Sara (fu t u re singer/dan cer, p ediat rician , an d/or n eu rosu rgeon ) an d m y h u sban d Mark for th eir love an d pat ien ce; m y d ear fam ily; an d to th e AANS/CNS Sect ion on Neurot rau m a an d Critical Care, of w h ich I have been an Execut ive Com m it tee m em ber for m ore th an 16 years an d prou d to be its Ch air (2014-2016). I w ou ld also like to th an k m y co-ed itor, P.B. Raksin , for h er collaborat ion , pat ien ce, an d diligen ce th rough ou t th e book’s product ion —a perfect m eld of m in d an d spirit . Fin ally, I w ould like to th an k m y colleagues an d residen t s at th e Icah n Sch ool of Medicin e at Moun t Sin ai for th eir support an d con t ribut ion s to th is atlas an d over th e years; an d th e n e at ten ding an d resid en t st a of th e Hofst ra Nor th Sh ore-LIJ Sch ool of Medicin e w h o spen d long n igh t s on call t reat ing em ergen cy n eurosurgical pat ien t s. I (PBR) w ou ld like to ackn ow ledge th e m any pat ien t s w h ose adversit y h as in form ed an d en h an ced m y clin ical experien ce (an d digit al im age collect ion ) in acute care n eurosurger y over th e past t w o decades. I w ou ld also like to th an k m y co-editor, Jam ie Ullm an , for invit ing m e to p ar t n er w ith h er in th is p roject an d en t ru st ing m e to h elp execu te h er vision . An d, to m y w ife Lisa—w h o h eld dow n th e for t w h ile I pored over m an u script s— m y etern al grat it ude an d a ect ion (an d a prom ise to clean th e o ce n ow th at th is task is com plete). Jam ie S. Ullm an , MD, FAANS, FACS P.B. Raksin , MD, FAANS
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Preface
Neu rosu rger y is n ot so sim ple. Drilling bu r h oles in th e em ergen cy depart m en t m ay relieve pressu re from an expan ding epidu ral h em atom a, but the ensuing un cont rolled arterial bleeding m ay resu lt in sign i can t blood loss, hypoten sion , an d death if on e is n ot skilled in h an dling th is sit u at ion . An d, alth ough traum a m ay be on e of th e m ore com m on reason s for em ergen t n eurosu rgical in ter ven t ion , acute care for n eu rosu rgical diseases is as w idely varied as the disciplin e itself. The ver y eclect ic nat ure of th ese em ergen t and urgent con dit ion s cont in ually ch allenges the skills obtain ed during the long n eu rosu rger y residen cy t rain ing period, dem an ding n ot on ly broad kn ow ledge and evolving techn ical skills, but pre-, in tra-, an d p ostoperat ive clin ical ju dgm en t th at can t ake a lifet im e to m aster—all for th e goal of im proving pat ien t outcom es. Appreciat ion of th is w eigh t y t ask m ust be cou pled w ith th e idea th at “learn ing” in n eurosurger y is a decidedly visual pursuit . Neu rosu rgeon s-in -t rain ing st u dy an atom ic rep resen t at ion s, dissect cadavers, an d obser ve th eir m en tors in th e operat ing room . With clin ical exp erien ce an d kn ow ledge acqu isit ion , th ere even t ually com es th e abilit y to t ran slate th e w rit ten w ords in a textbook in to m en t al im ages, or to im agin e on e’s w ay—step -by-step an d w ith variat ion s—th rough a procedu re before en tering th e operat ing th eater. The true value of a surgical atlas, then, lies in the presentation: the telling of a procedure in pictures. Historically, atlases h ave been designed to guide the learner through interventions in a step w ise fashion. In 1960, Jam es Leonard Poppen, MD, published his fam ed atlas entitled, An Atlas of Neurosurgical Techniques. This tom e presen ted procedures in diagram m atic fashion—useful to any neurosurgeon beginning to hone h is or her craft. In th at spirit, and in the spirit of great surgical atlases such as Zollinger’s Atlas of Surgical Operations, w e have set out to create a sim ilar volum e devoted to em ergen cy n eurosurgical procedures. Th is book w as w rit ten for n eurosurgeon s-in -t rain ing, as w ell as for th ose already in p ract ice w h o desire to m eet th e ch allenge of w h atever com es in to th e em ergen cy depar t m en t . Crit ical care pract it ion ers m ay also n d th is book ben e cial to un derstan ding th e surgical m an agem en t of n eurologic con dit ion s th at w ill dem an d th eir m edical expert ise in th e p ostop erat ive p eriod.
Th e book is divided in to six sect ion s. Sect ion I (Ch apters 1–10) covers th e basic procedures th at form th e bread an d but ter of cran ial n eu rosurger y for t raum a an d st roke, in cluding cran iotom ies for in t ra- an d ext ra-axial h em atom a, m an agem en t of p en et rat ing inju ries, an d decom pressive cran iectom y. Excellen t , com preh en sive review s of n eurom on itoring an d m an agem en t of n eurovascular inju ries com plem en t th ese ch apters. Sect ion II (Ch apters 11–18) focu ses on sp in al em ergen cy procedures—both t raum at ic and n on t raum at ic. Th e im port an t role of early surger y for acute t raum at ic spin e an d spin al cord in ju ries is in creasingly recogn ized; several ch apters are devoted to operat ive m an agem en t of th ese injuries. W h ile open procedu res st ill predom in ate in th e em ergen cy m an agem en t of th ese en t it ies, th e in creasing app licat ion of m in im ally invasive tech n iqu es in th is set t ing can n ot be ign ored. Ch apter 16 ou tlin es th e m in im ally invasive approach to th oracolum bar t rau m a. Non t rau m at ic em ergen cies, in clu ding ep id u ral sp in al com pression an d cau da equ in a syn drom e, are also addressed . Sect ion III (Ch apters 19–22) discu sses th e su rgical m an agem en t of n on t rau m at ic em ergen cies in cluding spon t an eous in t racran ial h em orrh age, in t racran ial in fect ion , p it u it ar y apop lexy, an d th e ever-h aun t ing ven t ricular sh un t m alfun ct ion . W h ile th e sequ elae of an eu r ysm al ru pt u re som et im es requ ire em ergen t su rgical in ter ven t ion , de n it ive m an agem en t often is u n dert aken m ore elect ively w ith in a 12- to 72-h our period. Th e tech n iqu e of an eu r ysm clip ping is th e su bject of several im p or tan t tom es an d is beyon d th e gen eral scope of this atlas. Sim ilarly, w h ile su rger y for rupt ured arterioven ous m alform at ion s is often deferred for a period of t im e to perm it resorpt ion of h em orrh age, p at ien ts m ay presen t w ith life-th reaten ing acute bleed s th at n ecessitate em ergen t in ter ven t ion for relief of m ass e ect . Th ese clin ical scen arios are addressed in Ch apter 19. W h ile on ly a select few neurosurgeon s h ave part icipated in th e th eater of w ar, w e felt it w ould be valuable to in clu de a sect ion addressing em ergen cy in ter ven t ion s for n eu rologic inju ries in com bat (Sect ion IV, Ch apters 23 an d 24). Key lesson s learn ed over th e past t w o decades of con ict h ave led to in creased su rvival from th ese d evast at ing inju ries. With th e loom ing th reat of terrorism , w e m ust be prepared to apply th ese tech n iques in civilian populat ion s sh ould th e n eed arise.
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Preface Sect ion V (Ch apters 25–27) en com p asses basic ten et s of recon st ruct ive su rger y. Th e m an agem en t of fron tal sin us injuries requ ires a com bin at ion of acu te care an d recon st ru ct ive ap proach es. Any con sid erat ion of decom pressive cran iectom y w ou ld n ot be com plete w ith ou t a discu ssion of it s n at u ral con sequ en ce: th e n eed for addit ion al, m ostly elect ive, su rger y to restore th e cran iu m to it s origin al p rotect ive p u rpose. Th e in form at ion p rovided is design ed to h elp th e su rgeon “ n ish th e job.” Fin ally, Sect ion VI (Ch apters 28 an d 29) con siders con cern s speci c to th e t reat m en t of h ead an d spin al injuries in th e pediat ric popu lat ion , in cluding steps for th e recon st ru ct ive repair of lep tom en ingeal cyst s. Th ese ch apters are d esign ed to h igh ligh t key di eren ces in th e acute, an d delayed, m an agem en t of injuries in ch ildren as com pared w ith adu lt s. Th e ch apters follow a st an dardized form at . In t roductor y com m en t ar y for each topic is follow ed by an accoun t ing of in dicat ion s for n eurosurgical in ter ven t ion an d preprocedu ral con siderat ion s. Th e operat ive procedure form s th e core of each sect ion . For th e reader’s conven ien ce, w e design ed th is book to keep illu st rat ion s an d p rocedu ral step s in close proxim it y. In
add it ion , m any step s are rep eated across ch apters (w ith variat ion ) to keep m ost of th e ch apters self-con t ain ed. Many of th e procedural steps are accom pan ied by “pearls”–addit ion al w isdom from th e su bject exper ts, geared tow ard en h an cing an operat ion’s success an d avoiding com plicat ion s. Each ch apter con cludes w ith a discussion of postoperat ive m an agem en t an d special con siderat ion s relevan t to th at top ic. Referen ces are kept to a m in im um . As th e pract ice of n eu rosurger y is as m uch an ar t as it is a scien ce, th ere w ill be n u an ces an d app roach es p referable to each in dividu al surgeon , an d th ere are often several w ays to accom plish th e sam e goal. Th e procedures outlin ed in th is book represen t th e best pract ices of th e various au th ors an d can be m odi ed based on su rgeon exp erien ce, preferen ce, an d p at ien t ch aracterist ics. An d, alth ough w e h ave m ade ever y at tem pt to provide a com preh en sive over view of th e m ost com m on ly en cou n tered em ergen cy p rocedu res, it is in evit able th at oth er em ergen cy con dit ion s w ill arise th at fall ou t side th e scope of th is project . It is our h ope th at th e in form at ion presen ted in th is book w ill ser ve as a platform upon w h ich to build st rategies for t reat ing m ore com p lex or less com m on em ergen cy presen t at ions. Jam ie S. Ullm an , MD, FAANS, FACS P.B. Raksin , MD, FAANS
Contributors
Sergey Abeshaus, MD Dep ar t m en t of Neu rosu rger y Seat tle Ch ildren’s Hospit al Seat tle, Wash ington P. David Adelso n , MD, FACS, FAAP Director Dian e an d Bru ce Halle En dow ed Ch air in Pediat ric Neu roscien ces Ch ief, Pediat ric Neurosurger y Barrow Neurological In st it ute at Ph oen ix Ch ildren’s Hospit al Ph oen ix, Arizon a Faiz U. Ahm ad, MD, MCh Assistan t Professor of Neu rosu rger y Em or y Un iversit y Grady Mem orial Hospit al Atlan ta, Georgia Ro cco A. Arm o nda, MD Division of Neurosurger y Walter Reed Nat ion al Militar y Medical Cen ter Beth esda, Mar ylan d Nelso n Astur Neto, MD Dep ar t m en t of Or th op edic Su rger y Cam p bell Clin ic Or th op aedics Mem p h is, Ten n essee Jo shua Bederso n , MD Professor an d Ch air Dep ar t m en t of Neu rosu rger y Icah n Sch ool of Medicin e at Moun t Sin ai New York, New York Sam uel R. Brow d, MD, PhD Director Dep ar t m en t of Neu rosu rger y an d On cology Cen ter for In tegrat ive Brain Research Seat tle Ch ildren’s Hospit al Harbor view Medical Cen ter Un iversit y of Wash ington Medical Cen ter Seat tle, Wash ington
Ro ss Bullo ck, MD, PhD Professor of Neurosurger y Un iversit y of Miam i Director, Clin ical Neurot raum a Jackson Hospital Miam i, Florida Laurence Davidso n, MD St a Neu rosu rgeon Division of Neurosurger y Walter Reed Nat ion al Militar y Medical Cen ter Beth esda, Mar ylan d Harel Deutsch, MD Associate Professor of Neurosu rger y Ru sh Un iversit y Medical Cen ter Ch icago, Illin ois Do niel Drazin, MD Dep ar t m en t of Neu rosu rger y Cedars Sin ai Medical Cen ter Los Angeles, Californ ia Richard G. Ellen bogen , MD, FACS Professor an d Ch airm an Dep ar t m en t of Neu rological Su rger y Un iversit y of Wash ington At ten ding Neurosurger y Harbor view Medical Cen ter Seat tle Ch ildren’s Hospital Seat tle, Wash ington Do m enic P. Espo sito, MD, FACS, FAANS Professor of Neurosurger y (Ret .) Un iversit y of Mississip pi Neurosurgical Con su ltan ts, LLC Jackson , Mississipp i Michael G. Fehlings, MD, PhD, FRCSC Neurosurgeon Division of Neurosurger y Toron to Western Hospital Toron to, On tario, Can ada
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Contributors Antho ny Figaji, MD Professor an d Head Pediat ric Neurosurger y Un iversit y of Cap e Tow n In st it ute for Ch ild Health Red Cross Ch ildren’s Hospital Cape Tow n Cap e Tow n , Sou th Africa Yakov Go lo go rsk y, MD At ten ding in Neurosurger y Mou n t Sin ai Medical Cen ter New York, New York Abilash Haridas, MD Assistan t Professor of Neu rosu rger y Wayn e State Un iversit y Sch ool of Medicin e Pediat ric Neurosurger y Cerebrovascu lar Neu rosu rger y Ch ildren’s Hospital of Mich igan Det roit , Mich igan Mark R. Harrigan , MD Associate Professor Un iversit y of Alabam a Medical Cen ter Birm ingh am , Alabam a Odette A. Harris, MD, MPH Associate Professor of Neu rosu rger y Director of Brain Inju r y Stan ford Sch ool of Medicin e Hosp it al an d Clin ics Stan ford, Californ ia Jam es S. Harro p, MD Professor of Or th opedic an d Neurological Su rger y Director, Sp in e an d Periph eral Ner ve Su rger y Th om as Je erson Un iversit y Ph iladelph ia, Pen n sylvan ia Brian Ho o d, MD Major USAF, MC Assistan t Professor of Clin ical Medicin e Un iform ed Un iversit y of Health Scien ces San An ton io Milit ar y Medical Cen ter San An ton io, Texas Jo seph Hsieh, MD Assistan t Professor Th e Vivian L. Sm ith Dep art m en t of Neu rosu rger y Th e Un iversit y of Texas Health Cen ter Houston , Texas Michael C. Huang, MD Assistan t Clin ical Professor of Neu rological Su rger y Un iversit y of Californ ia, San Fran cisco San Fran cisco Gen eral Hospital an d Traum a Cen ter San Fran cisco, Californ ia Asha Iyer, MD Residen t in Neu rosu rger y Icah n Sch ool of Medicin e at Moun t Sin ai New York, New York
Jo hn A. Jane Jr., MD Associate Professor of Neu rosu rger y an d Pediat rics Pediat rics Division Director Un iversit y of Virgin ia Ch arlot tesville, Virgin ia Arthur Jenkins, MD, FACS Associate Professor of Neu rosu rger y Icah n Sch ool of Medicin e at Moun t Sin ai New York, New York Bow en Jiang, MD Resid en t in Neu rosu rger y Joh n s Hopkin s Hospital Balt im ore, Mar ylan d J. Patrick Jo hnso n , MD, MS, FACS Director of Sp in e Edu cat ion an d Neu rosu rger y Spin e Fellow sh ip Program Depar t m en t of Neurosurger y Cedars Sin ai Medical Cen ter Th e Sp in e In st it u te Fou n dat ion Los Angeles, Californ ia Professor of Neu rosurger y UC Davis Medical Cen ter Sacram en to, CA Erin N. Kiehna, MD Assist an t Professor of Neu rosu rger y Ch ildren’s Hospital Los Angeles Los Angeles, Californ ia Kee Kim , MD Associate Professor an d Ch ief Depar t m en t of Spin al Neurosurger y Co-director, Sp in e Cen ter Un iversit y of Californ ia, Davis Sch ool of Medicin e Sacram en to, Californ ia Paul Klim o Jr., MD, MPH Associate Professor of Neu rosu rger y Un iversit y of Ten n essee Associate, Sem m es-Mu rp h ey Neu rologic & Sp in e In st it u te Mem ph is, Ten n essee Mathieu Laro che, MD, MSc, FRCSC Assist an t Professor of Neu rosu rger y Un iversit y of Mon t réal Neu rosurgeon Hôpital du Sacré- Coeu r de Mon t réal Mon t réal, Qu ébec, Can ada A. Stew art Levy, MD Neu rosurgeon St . An th ony Hosp ital Ch ief of Neurosurger y Cen t u ra Neu roscien ce & Spin e Lakew ood, Colorado Casey Madura, MD Resid en t in Neu rosu rger y Un iversit y of Wiscon sin Hospital an d Clin ics Madison , Wiscon sin
Contributors Geo rey T. Manley, MD, PhD, Professor in Residen ce an d Vice Ch airm an Dep ar t m en t of Neu rological Su rger y Co-Director an d Prin cip al Invest igator Brain an d Spin al Inju r y Cen ter (BASIC) Ch ief of Neurosurger y San Fran cisco Gen eral Hospit al Un iversit y of Californ ia, San Fran cisco San Fran cisco, Californ ia Justin Mascitelli, MD Residen t in Neurosurger y Icah n Sch ool of Medicin e at Moun t Sin ai New York, New York Leo n E. Mo o res, MD, MS Professor of Neurosu rger y Virgin ia Com m onw ealth Un iversit y Professor of Surger y an d Pediat rics Un iform ed Ser vices Un iversit y CEO, Pediat ric Specialists of Virgin ia Director of Pediat ric Neuroscien ces In ova Health System Fairfax,Virgin ia Co rey M. Mo sso p, MD Neurosu rger y Ser vice Walter Reed Nat ion al Militar y Medical Cen ter Silver Sp ring, Mar ylan d So riaya Motivala, MD Assistan t Professor of Neu rosu rger y Icah n Sch ool of Medicin e at Moun t Sin ai New York, New York Michael S. Muhlbauer, MD Dep ar t m en t of Pediat ric Neu rosu rger y Sem m es-Murph ey Neurologic & Spin e In st it ute Clin ical Assistan t Professor Un iversit y of Ten n essee Le Bon h eur Ch ildren’s Hospital Mem p h is, Ten n essee Christo pher J. Neal, MD Neurosu rger y Ser vice Walter Reed Nat ion al Militar y Medical Cen ter Beth esda, Mar ylan d Kalm o n D. Po st, MD Professor an d Ch airm an -Em erit us Dep ar t m en ts of Neu rosu rger y, On cological Scien ces, Medicin e, En docrin ology, Diabetes, an d Bon e Disease Icah n Sch ool of Medicin e at Moun t Sin ai New York, New York Jam es G. Purzner, MD Residen t in Neurosurger y Un iversit y of Toron to Toron to Western Hospit al Toron to, On t ario, Can ada
Teresa S. Purzner, MD Residen t in Neu rosurger y Un iversit y of Toron to Toron to Western Hospital Toron to, On tario, Can ada Craig Rabb, MD Professor of Neurosurger y Director Neurot raum a Program OU Physician s Neurosurger y Oklah om a Cit y, Oklah om a P.B. Raksin, MD, FAANS Assistan t Professor, Depar t m en t of Neurosurger y Ru sh Un iversit y Medical Cen ter Director, Neurosu rger y ICU Ch ief, Sect ion Neurot raum a & Neurocrit ical Care Joh n H. St roger Jr Hospital of Cook Cou n t y (form erly Cook Cou n t y Hospital) Ch icago, Illin ois Pal S. Ran dhaw a, MD Residen t in Neu rosurger y Un iversit y of Colorado Au rora, Colorado Jo nathan Raso uli, MD Residen t in Neu rosurger y Icah n Sch ool of Medicin e at Mou n t Sin ai New York, New York Daniel Resnick, MD, MS Professor an d Vice Ch airm an Residen cy Program Director Co-Director, Sp in al Su rger y Program Dep ar t m en t of Neu rological Su rger y Un iversit y of Wiscon sin Sch ool of Med icin e an d Pu blic Health Mad ison , Wiscon sin Ro berto Rey-Dio s, MD Assistan t Professor of Neurosurger y Un iversit y of Mississip pi Medical Cen ter Jackson , Mississipp i Boyd F. Richards, DO Dep ar t m en t of Neu rological Su rger y St . Joh n Providen ce Health System Mich igan Spin e an d Brain Su rgeon s South eld, Mich igan Michael K. Ro sner, MD Ch ief of Neurosurger y In tegrated Ser vice Assistan t Professor Un iform ed Ser vices Un iversit y Walter Reed Nat ion al Militar y Medical Cen ter Wash ington , DC Ali Shirzadi, MD Neurosurgeon South Bay Brain an d Spin e San Jose, Californ ia
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Contributors Branko Skovrlj, MD Residen t in Neu rosu rger y Icah n Sch ool of Medicin e at Moun t Sin ai New York, New York
An an d Veeravagu, MD Ch ief Residen t in Neurosu rger y Stan ford Un iversit y Stan ford, Californ ia
Peter J. Taub, MD, FACS, FAAP Professor of Su rger y an d Pediat rics Associate Director, Residen cy Train ing Program Ch ief, Cran iom axillofacial Su rger y Co-Director, Cleft an d Cran iofacial Cen ter Mou n t Sin ai Medical Cen ter New York, New York
Michael Y. Wang, MD Depar t m en t s of Neu rological Surger y & Reh abilitat ion Medicin e Un iversit y of Miam i Miller Sch ool of Medicin e Miam i, Florida
Shelly D. Tim m o ns, MD, PhD, FACS, FAANS Clin ical Associate Professor of Neurosurger y Tem ple Un iversit y Director of Neu rot rau m a Associate Director for Neu roscien ces Adu lt ICU, GMC Residen cy Program Director Geisinger Health System Danville, Pen n sylvan ia Ro land A. To rres, MD Ch airm an of Neurosurger y Alaska Nat ive Med ical Cen ter An ch orage, Alaska Michael Turn er, MD, PhD Neurosurgeon Frisco Spin e Frisco, Texas Jam ie S. Ullm an , MD, FAANS, FACS Associate Professor, Dep art m en t of Neu rosu rger y Hofst ra North Sh ore-LIJ Sch ool of Medicin e Director of Neu rot rau m a Nor th Sh ore Un iversit y Hospital Man h asset , New York
William C. Warner Jr., MD Depar t m en t of Orth opaedics Cam p bell Clin ic Orth op aedics Mem ph is, Ten n essee Nirit Weiss, MD Assist an t Professor of Neu rosu rger y Icah n Sch ool of Medicin e at Moun t Sin ai New York, New York Sanjay Yadla, MD, MPH Depar t m en t of Neurosurger y Alexian Broth ers Neu roscien ces In st it u te Elk Grove Village, Illin ois Benjam in M. Zussm an, MD Resid en t in Neu rosu rger y Un iversit y of Pit tsbu rgh Pit t sbu rgh , Pen n sylvan ia
I
Cerebral Trauma and Stroke
1
Surgery for Epidural and Subdural Hematomas Shelly D. Tim m ons
Introduction
Preprocedure Considerations
Rapid evacu at ion of ext ra-axial h em atom as after t rau m a can be a life-saving in ter ven t ion . W h ile th ere is n o absolute cuto t im e after w h ich pat ien t s fare w orse, m any st udies h ave dem on st rated bet ter outcom es w ith earlier evacu at ion . Surgical plan n ing m u st take in to con siderat ion th e presen ce of oth er in t racran ial lesion s an d th e p at ien t’s clin ical stat u s. Th e presen ce of p olyt rau m a, th e p at ien t’s h em odyn am ic st at u s,1 an d th e p resen ce of coagu lopathy m u st be con sidered an d addressed w h ile n ot delaying surgical in ter ven t ion .
Radiographic Imaging
Indications • Su rgical in ter ven t ion is app ropriate for epidural hem atom as
•
2
(EDH) w ith th e follow ing ch aracterist ics 2 ◦ Glasgow Com a Scale (GCS) score 8 an d an isocoria → operat ing room as soon as p ossible ◦ Hem atom a volu m e 30 cm 3 ◦ Hem atom a volu m e , 30 cm 3 bu t accom p an ied by: ▪ Th ickn ess 15 m m ▪ Midlin e sh ift 5 m m ▪ GCS 8 ▪ Focal m otor de cit ◦ E aced cistern s ◦ Deteriorat ing n eu rologic st at u s Su rgical in ter ven t ion is ap prop riate for subdural hem atom as (SDH) w ith th e follow ing characterist ics 3 ◦ Th ickn ess 10 m m ◦ Midlin e sh ift 5 m m ◦ Th ickn ess , 10 m m an d m idlin e sh ift , 5 m m but accom p an ied by: ▪ Neu rologic w orsen ing by 2 or m ore poin t s on th e GCS ▪ Asym m et ric pupils ▪ Fixed an d dilated pupils ▪ In t racran ial pressure (ICP) 20 m m Hg
• Com puted tom ography (CT) is essen t ial to evaluate for: ◦ Th e p resen ce an d size of ext ra-axial h em atom a ◦ Degree of m idlin e sh ift ◦ Ap p earan ce of p erim esen cep h alic cistern s ◦ Presen ce of oth er sp ace-occu pying lesion s • Preoperative im aging (Fig. 1.1).
Medications • Preoperat ive an t ibiot ics: eith er a ceph alosporin or van com y•
•
cin (if pen icillin allergic) sh ould be given . Th e pat ien t sh ould be given seizure prophylaxis at earliest opport un it y after arrival to th e h ospit al. Eviden ce-based gu id elin es su p p or t th e u t ilizat ion of an t iconvu lsan ts for 7 days in pat ien t s follow ing t raum at ic brain injur y.4 Fresh frozen plasm a an d/or oth er blood product s/factors sh ou ld be adm in istered p reop erat ively an d in t raop erat ively as n eeded to correct coagu lopathy.
Operative Field Preparation • Th e h ead m ay be posit ion ed on a dough n ut or h orsesh oe • •
•
h ead h old er, rath er th an a th ree-pin ion h ead h older, to facilit ate m ore rapid progression to brain decom pression . The operative eld should be prepared using an iodine-based sterile prep solution, provided the patient has no iodine allergies. Th e use of ch lorh exidin e is con t roversial; product in ser t in form at ion bars th e u se for p rocedu res exp osing th e cerebral m en inges. In cases w ith kn ow n bet adin e or iodin e allergies, ch lorh exidin e or alcoh ol prep can be u sed. Th e in cision s are m arked an d, after n al sterile draping, in lt rated w ith 1% lidocain e w ith epin eph rin e 1:100,000.
1
Surgery for Epidural and Subdural Hem atom as
a
b
c
d
Fig. 1.1a–d CT scan is the modalit y m ost commonly utilized in the perioperative set ting. (a) Epidural hematomas demonstrate a characteristic convex shape (due to adherence of the dura at the suture lines) and are t ypically accompanied by a (b) fracture (arrow). (c) Subdural hematomas by contrast, are not bound by sutures and assume a crescentic appearance, layering over the convexit y. (d) A small subdural hematoma may be accompanied by disproportionate mass e ect and midline shift.
3
I Cerebral Traum a and Stroke
Operative Procedure Positioning (Fig. 1.2a, b)
b
a
4
Figure
Procedural Steps
Pearls
Fig. 1.2
(a, b) The head is turned so as to expose the operative hemicranium. The patient whose neck has not yet been cleared can be positioned in the cervical collar by placing a bolster under the ipsilateral shoulder and the ipsilateral arm across the chest. Pressure points should be padded appropriately. The head may be placed on a foam or gel doughnut to expedite positioning.
• Discuss positioning with the anesthesiology team . The endotracheal tube (ETT) should
• • • • •
exit the contralateral side of the m outh if placed orally, and should be secured in place using tape, ETT collar, etc. The eyes should be protected from corneal abrasion by placing ointm ent under each lid and taping the lids shut. Allowance for central venous catheters, peripheral intravenous catheters, and arterial lines should be m ade, with these positioned toward the anesthesiology team if possible. Foley catheters should always be placed and should be accessible to the anesthesia team . Pin xation may also be used, but positioning on a doughnut or horseshoe head holder m ay expedite decompression of the brain. The head should be positioned just at or slightly overhanging the end of the table and the sterile craniotomy drape placed so that it hangs vertically to facilitate drainage of irrigation by gravit y. Final draping should exclude the anesthesia setup, using a vertical drape. An exit site for a subgaleal drain should be included in the area exposed by the sterile draping. Reverse Trendelenburg positioning m ay be used to provide elevation of the head to help reduce cerebral edem a.
1
Surgery for Epidural and Subdural Hem atom as
Skin Incision (Fig. 1.3)
Figure
Procedural Steps
Pearls
Fig. 1.3
The skin incision should be planned to create a craniotomy su cient to access the entire hematoma. The question mark or reverse question mark incision (illustrated here) is used commonly to access large traumatic extra-axial hematomas.
• Other skin incisions m ay be utilized to evacuate sm aller hematom as. However, before •
• • •
com mit ting to a m ore lim ited exposure, consideration should be given to the degree of brain swelling anticipated. When using a question m ark incision, care should be taken not to place the incision too close to the pinna of the ear. A m argin of at least 1 cm should be used. Likewise, the vertical lim b of the incision should be placed at least 1 cm anterior to the tragus. The scalp m ay be elevated o of the underlying bone and retracted out of the way. Scalp clips m ay be applied to the scalp edges to aid in hem ostasis. Prior to opening the scalp over the temporalis m uscle, an instrum ent m ay be passed over the m uscle fascia and the skin divided down to the level of the instrum ent with a scalpel. The temporalis m ay then be divided in parallel with the incision using Bovie cautery. Branches of the super cial and m iddle temporal arteries may be encountered and m ay be ligated and divided sharply, or cauterized with the bipolar cautery.
5
I Cerebral Traum a and Stroke
Subcutaneous Dissection (Fig. 1.4)
Figure
Procedural Steps
Pearls
Fig. 1.4
For rapid opening, the temporalis muscle may be elevated simultaneously w ith the scalp ap.
• The temporalis m uscle m ay be elevated o of the underlying bone using a sharp •
•
6
periosteal elevator, such as a Langenbeck, or using the Bovie cautery. The musculocutaneous ap should be protected from strangulation by placing dry sponges (counted) behind the ap, which is then secured using shhooks. A sponge soaked with irrigation infused with epinephrine m ay be placed on the undersurface of the galea and m uscle to aid in hemostasis. Bipolar cautery m ay be used sparingly on scalp and m uscle vessels, taking care not to shrink the galea.
1
Surgery for Epidural and Subdural Hem atom as
Craniotomy (Fig. 1.5a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 1.5
(a) Bur holes are placed at the perimeter of the planned bone ap, leaving su cient bony margins so that the plating hardw are is not located immediately under the skin incision at closure.
• After creation of the bur holes using a high-speed
A no. 3 Pen eld dissector is used to strip the dura o of the undersurface of the bone at each bur hole. If possible, the Pen eld should be used to make a communication, in this same plane, betw een adjacent bur holes. The high-speed drill attachment is converted to a cutting bit w ith a footplate and used to connect each pair of bur holes circumferentially.
•
The bone ap should be secured in place w ith a nger prior to making the nal cut.
•
drill, bone wax is applied to the raw bone edges where necessary. Excess wax is rem oved, along with any obstructive bone edges deep in the bur holes, with a cup curet te. A larger instrum ent, such as a Langenbeck periosteal elevator, m ay be used to elevate the ap, as long as the underlying dura is protected from the sharp edge of the instrum ent. The explanted bone ap should be cleared of hem atom a and blood and placed in irrigation infused with antibiotics on the back table until ready to be replaced. Center holes may be m ade later in the bone ap for epidural tack-up sutures.
(b) As the bone ap is elevated o of the center dura, again using a no. 3 Pen eld, the edge of the ap should be securely grasped and eventually removed from the exposure.
7
I Cerebral Traum a and Stroke
Evacuation of Epidural Hematoma (Fig. 1.6)
Figure
Procedural Steps
Pearls
Fig. 1.6
As the bone ap is elevated, an epidural hematoma w ill be appreciated immediately in the extradural space. This may be removed using irrigation and suction.
• Evacuation of an epidural hem atom a will often yield both organized
The source of bleeding should be addressed as quickly as possible, utilizing bipolar cautery on the vessel itself, and/or bone w ax on the foramen spinosum w here the vessel enters the cranium.
8
hem atom a and liquid blood. The hem atom a is often adherent to the bleeding vessel, com monly the m iddle m eningeal artery in the anterior temporal area. This, in turn, m ay be associated with a fracture of the squam ous portion of the temporal bone.
• Other sources of epidural hem atom as m ay be handled sim ilarly. Venous epidural hem atom as sometim es require application of gel foam soaked in throm bin and gentle pressure, or Bovie cautery or bone wax to bleeding bone edges.
1
Surgery for Epidural and Subdural Hem atom as
Dural Opening (Fig. 1.7)
Figure
Procedural Steps
Pearls
Fig. 1.7
The dura is opened w idely enough to allow access to as much of the subdural space as possible in the craniotomy exposure.
• For curvilinear incisions, at least 1 cm of dura should be left bet ween the
The initial dural opening may be made w ith a no. 11 scalpel. The dural edges may then be grasped w ith ne -toothed forceps, elevated, and the remainder of the opening performed w ith ne Metzenbaum or tenotomy scissors. Occasionally, if the brain is very edematous, the opening may be made w ith a no. 11 scalpel over a groove director.
• • •
durotomy and the bone edge to prevent retraction, causing di cult y with closure. If the brain is signi cantly edem atous and the dura is taut, relaxing incisions m ay be m ade in the perim eter of a curvilinear incision to prevent strangulation of the underlying brain by the dural edge. The dural edges should be secured with 4-0 braided nylon sutures, and held in place with m osquito hem ostats, either to gravit y or secured to the drapes without undue tension. The dural ap or aps should be weighted with hem ostats in order to prevent shrinkage during the procedure as m uch as possible. Dural vessels m ay be coagulated with the bipolar at the edges of the cut dura.
9
I Cerebral Traum a and Stroke
Evacuation of Subdural Hematoma (Fig. 1.8)
Figure
Procedural Steps
Pearls
Fig. 1.8
The subdural hematoma (SDH) is seen overlying the surface of the brain and is evacuated w ith irrigation and suction.
• The source of any SDH should be sought. The source is often a cortical surface vein or artery. •
•
10
SDHs occasionally m ay em anate directly from a surface contusion. Gentle irrigation with sterile saline should be used and the entire perim eter of the dural exposure explored with adequate lighting to ensure that the hem atom a has been completely evacuated. A brain retractor blade m ay be used to gently depress the brain during this phase. Well-form ed hematom as m ay be grasped with biopsy forceps and gently elevated from the brain surface while ushing the area with ample irrigation. If an active bleeding source is identi ed (which is not always possible), the bleeding should be stopped with bipolar electrocautery, gelatin sponge soaked in throm bin, and gentle pressure with a cot ton pat tie. The site should be irrigated again to ensure no active bleeding prior to dural closure.
1
Surgery for Epidural and Subdural Hem atom as
Dural Closure (Fig. 1.9)
Figure
Procedural Steps
Pearls
Fig. 1.9
After adequate evacuation of the hematoma, the dura is closed w ith 4-0 braided nylon suture.
• Closure of the dura should be a ected in a watertight fashion if possible. Over the
Epidural tack-up sutures are placed through small drill holes placed around the perimeter of the craniotomy. A central epidural tacking stitch may be brought out through tw o holes drilled in the bone ap.
•
•
convexit y, watertight closure is not imperative. The dura may be closed with simple running, running-locking, or interrupted sutures. For large dural defects not am enable to prim ary closure due to shrunken dura, torn or adherent dura (com m on in the elderly), and/or brain swelling, a variet y of dural substitute m aterials are available. The dura m ay be patched with suturable graft m aterials or autograft from the patient’s own galea or m uscle fascia, or closed with graft m aterials alone. Prior to placing the nal few sutures, the subdural space should be irrigated a nal tim e. When a large subdural potential space rem ains (as in the case of an elderly patient and/or one with a slack brain), a sm all am ount of irrigation m ay be left in the subdural space to lessen the risk of extensive postoperative pneum ocephalus.
11
I Cerebral Traum a and Stroke
Bone Flap Replacement (Fig. 1.10)
12
Figure
Procedural Steps
Pearls
Fig. 1.10
Follow ing evacuation of either an epidural or subdural hematoma, the bone ap is replaced in its anatomic position, using a cranial plating system. The central epidural tacking stitch is secured.
• Many t ypes of cranial plating system s, with a variet y of plate shapes •
and sizes, are available. These are generally m ade of titanium , which is nonm agnetic, allowing for later m agnetic resonance im aging. Resorbable plates and screws are available for children. Alternatively, the bone ap m ay be replaced with silk suture to avoid rigid xation in the growing skull.
1
Surgery for Epidural and Subdural Hem atom as
Drain Placement (Fig. 1.11)
Figure
Procedural Steps
Pearls
Fig. 1.11
For large aps, a subgaleal drain may be used to lessen the risk of postoperative subgaleal hematoma.
• The drain should exit from a separate stab incision, formed with a trocar or no. 11 knife, and should be secured at its skin exit site with a nylon stitch. The drain is at tached to bulb suction.
13
I Cerebral Traum a and Stroke
Closing
• Pat ien ts w ith severe inju ries w ill likely h ave addit ion al in -
• If m ass e ect h as been relieved adequ ately an d th e brain is
• • • •
• •
slack (creat ing dead sp ace in w h ich blood m ay accu m u late postoperat ively), th e pat ien t’s en d-t idal CO2 level sh ould be allow ed to rise gradu ally to 30 to 35 m m Hg (rough ly equ ivalen t to p CO2 of 35 to 40 m m Hg) d u ring closu re. If ongoing coagu lopathy is obser ved, m easu res sh ou ld be t aken to correct clot t ing p aram eters in t raop erat ively. Sterile salin e irrigat ion is ut ilized in th e in t radu ral space. After du ral closu re, cop iou s am ou n t s of sterile salin e in fu sed w ith an t ibiot ic solu t ion (e.g., bacit racin ) are used to irrigate th e w oun d. Tem poralis m uscle and fascia are reapproxim ated w ith 0-gauge braided absorbable suture. The galea is closed w ith interrupted, inverted, 2-0 braided absorbable suture. As the scalp closure proceeds, the scalp clips m ay be rem oved successively, by spreading w ith the scalp clip applier or a hem ostat. Th e skin m ay be closed w ith nylon or oth er n on braided sut ure, or w ith st aples. Extern al su t ure is requ ired on th e scalp, as th ere is n ot a w ell-develop ed su bcu t icu lar layer. Th e w ou n d m ay be dressed in a variet y of w ays. Th e auth or prefers to apply a st rip of n on adh eren t pet rolat um gauze over su t u res or st ap les to p reven t p u lling. Th is base dressing, in t urn , is covered w ith n arrow gau ze ban dages to absorb m in or oozing postoperat ively. Th e dressing is secured w ith st retchy dressing t ape, applied un der sligh t tension to assist in cision al h em ostasis. St rip s of dressing tape m ay be u sed to follow th e cur vat ure of th e h ead parallel to th e in cision for close adh eren ce. Th e dressing is rem oved after 24 h ou rs, an d th e pat ien t is allow ed to clean se th e w oun d w ith m ild soap an d w ater.
• •
vasive n eu rom on itoring (an ICP, extern al ven t ricu lar drain , brain t issue oxygen m on itor, or a com bin at ion th ereof) to gu ide m an agem en t . Invasive h em odyn am ic m on itoring (arterial lin e, cen t ral ven ous lin e, Sw an -Gan z cath eter) m ay be in dicated to assist m an agem en t in crit ically ill pat ien t s. Drain s sh ou ld be m on itored for ou t pu t ever y 4 h ou rs for th e rst 8 h ou rs an d th en ever y 8-h ou r sh ift . Th e in cision an d/or dressing sh ould be m on itored for bleeding in it ially, an d for er yth em a, exudate, an d /or edem a subsequen t to th e in it ial postoperat ive period.
Medication • Postop erat ive an t ibiot ics are con t in u ed for 24 h ou rs u n less •
• • • •
th ere w as gross con t am in at ion presen t at th e t im e of surger y, in w h ich case th is period m ay be exten ded. Seizu re prop hylaxis sh ou ld be con t in u ed for a total of 7 days for p at ien ts w ith EDH or SDH. Th e presen ce of d ocu m en ted seizu res m ay p rovide an in dicat ion to con t in u e th erapy beyon d th is w in dow. Hyperosm olar th erapy—m an n itol an d/or hyper ton ic salin e— m ay be in dicated for ICP con t rol dep en d ing on th e clin ical pict ure. Sedat ion an d /or n eu rom u scu lar p aralyt ics m ay be in dicated to assist ICP con t rol depen ding on th e clin ical pict ure. Pressor support m ay be n ecessar y to m ain tain adequate cran ial perfu sion pressu re d ep en ding on th e clin ical pict u re. Ongoing coagu lopathy sh ou ld be corrected w ith fresh frozen plasm a or oth er appropriate blood product s/factors.
Radiographic Imaging
Postoperative Management Monitoring
• Postop erat ive im aging (Fig. 1.12).
Further Management • Drain s are rem oved on th e rst p ostop erat ive day, provid ed
• Th e pat ien t sh ou ld be m on itored in th e post-an esth esia care u n it (recover y room ), progressive care un it , or in ten sive care un it w ith frequen t n eurologic ch ecks, occurring at least h ou rly in it ially. Th e p at ien t’s preoperat ive st at us an d p ostoperat ive course w ill dict ate th e t im ing of t ran sit ion to less in ten sive m on itoring.
14
• •
input h as slow ed su cien tly. If th ere is sign i can t out p ut , rem oval m ay be d elayed an oth er 1 to 2 days. Th e dressing is rem oved an d th e w oun d is clean sed w ith w arm w ater an d m ild soap or sh am p oo after 24 h ou rs. Skin su t u res or st ap les are rem oved on or abou t p ostop erat ive day 10 to 14.
1
Surgery for Epidural and Subdural Hem atom as
a
b Fig. 1.12a, b Axial CT images demonstrating resolution of (a) epidural hematoma and (b) subdural hematoma.
Special Considerations Preoperat ive plan n ing is im port an t in th e m an agem en t of t raum at ic SDHs. Plan n ing for p ossible decom p ressive cran iectom y m u st often be in corp orated in to th e p osit ion ing, in cision , an d bon e ap creat ion (see Ch apter 4). Pat ien t s w h o are likely to require th e bon e ap to be left out in clude th ose w ith m idlin e sh ift ou t of p roport ion to th e th ickn ess of th e SDH, th ose w ith e aced cistern s, th ose w ith blu n t vascu lar inju r y or isch em ia to th e a ected h em isph ere, or th ose w ith a sign i can t am oun t of u n derlying con t u sion .
References 1. Bu llock MR, Ch esn u t RM, Clifton GL, et al. Man agem en t an d progn osis of severe t raum at ic brain injur y. J Neu rot raum a 2000; 17:449–597 2. Bu llock MR, Ch esn u t R, Gh ajar J, et al. Su rgical m an agem en t of acute epidural h em atom as. Neurosurger y 2006;58:S7–S15 3. Bu llock MR, Ch esn u t R, Gh ajar J, et al. Su rgical m an agem en t of acute subdural h em atom as. Neurosurger y 2006;58:S16–24 4. Bu llock et al. An t iseizu re p rop hylaxis. In : Guidelin es for th e Man agem en t of Severe Traum at ic Brain Injur y, 3rd ed. J Neurot raum a 2007;24:S83–86
15
2
16
Chronic Subdural Hematomas Branko Skovrlj, Jonathan Rasouli, A. Stew art Levy, P.B. Rak sin, and Jam ie S. Ullm an
Introduction
Indications
Ch ron ic su bdu ral h em atom a (CSDH) is on e of th e m ost com m on ly t reated n eu rosu rgical disord ers in th e w orld. Th e 2006 Am erican Associat ion of Neurological Surgeons procedural survey rep or ted over 43,000 bu r h oles perform ed for th e evacu at ion of ext ra-axial (subdural/epidural) h em atom as.1 Th e m ost com m on pat ien t ch aracterist ics are elderly m ales w ith or w ith out a h istor y of h ead t rau m a.2,3 Addit ion al risk factors in clu de a h istor y of alcoh olism , th e p resen ce of an in tern al cerebrosp in al u id (CSF) sh u n t , an d acqu ired or congen it al bleeding d iath esis.4 CSDHs are often u n ilateral, bu t p resen t as bilateral in ap p roxim ately 16 to 25%of cases.3,5 Th e m ost com m on presen t ing sym ptom s in clu de h eadach e, ataxic gait , con fu sion , ap h asia, an d variou s n on speci c com p lain t s. If th e CSDH is large an d causes sign i can t m ass e ect , paresis, seizure, an d com a m ay en su e. Mort alit y st at ist ics var y am ong in st it u t ion s, bu t gen erally range from 5 to 16%.6,7 Several th eories exist to exp lain th e p ath ogen esis of CSDH. The prevailing hypoth esis is th at m ost start as acute subdural bleeds th at t rigger a local in am m ator y respon se in th e surroun ding m en inges. In am m at ion t riggers th e m igrat ion of broblast s, w hich th en create m em bran es th at organ ize th e clot an d secrete vascu lar en doth elial grow th factor (VEGF) th at , in t urn , prom otes th e form at ion of capillaries w ith in th ese m em bran es.8 Over t im e, th ese m em bran e capillaries bleed an d preven t th e blood from being reabsorbed. Hem oglobin even t u ally is broken dow n in to h em osiderin , leading to th e ch aracterist ic ap p earan ce of CSDH on com pu ted tom ograp hy (CT)/m agn et ic reson an ce (MR) im aging (Fig. 2.1). Man agem en t of CSDH t yp ically involves su rgical evacu at ion of th e clot an d placem en t of post surgical drains to preven t reaccum ulation of blood in th e subdural space. In part icular, th e use of drain s after bur h ole evacuat ion of CSDH has been sh ow n to redu ce both recu rren ce an d m ort alit y at 6 m on ths.9 Several op erat ive ap proach es are available. Bu r h ole drain age is perform ed m ost com m on ly. A “m in i”-cran iotom y m ay augm en t visu alizat ion of th e subdural space. W hen th e radiograph ic appearan ce is favorable, bedside p rocedures—such as m in im ally invasive t w ist drill cath eter placem en t or suct ion evacu at ion —can be u sed to good e ect . In addit ion to th ese su rgical tech n iques, several sm all st u dies h ave suggested th at dexam eth ason e therapy m igh t sh ow som e prom ise in t reat ing CSDH.10,11 New er p h arm acological t reat m en t , such as th e u se of t ran exam ic acid (an an t ith rom bolyt ic agen t), is invest igat ion al.12 CSDH recu rren ce rates var y am ong in st it u t ion s, bu t gen erally range from 8 to 16%.13,14 Several st udies h ave suggested that CSDH recurren ce rates are h igh er w ith bilateral CSDH, w ith large volum es of pn eum oceph alus after evacuat ion , an d w ith use of an t icoagu lat ion th erapy.13,14
All Procedures • Su bacu te or ch ron ic su bdu ral h em atom a w ith m axim u m •
th ickn ess . 10 m m an d/or m idlin e sh ift . 7 m m Su bacu te or ch ron ic su bd u ral of any th ickn ess cau sing m ass e ect , m idlin e sh ift , or n eu rologic sign s an d sym ptom s.
Minimally Invasive • Favorable CT im aging ch aracterist ics—a un iform ly isoden se
•
• •
or hypoden se collect ion in th e subdural space—are presen t . Th is suggest s th e subdural h em atom a is su cien tly lique ed to perm it drain age via a ven t riculostom y cath eter. The presence of an isodense, or even slightly hyperdense, “ground glass” appearance is not necessarily a contraindication to catheter drainage. This ph enom enon is seen som etim es in the set ting of a subacute or “acute on chronic” subdural hem atom a, often w ith a gradual gradient from anterior hypodensit y to posterior hyperdensit y (re ecting dependen t acute blood m ixed w ith th e predom inantly ch ronic hem atom a). These usually can be drained e ectively w ith a bedside catheter or suction evacuation procedure. A sm all am oun t of acute, hyperden se subdural blood w ith in a larger, m ostly ch ron ic, hypoden se collect ion is n ot n ecessarily a con t rain d icat ion . W h ile adequate drain age can be ach ieved even in th e presen ce of a few su bdu ral m em bran es, exten sive m em bran es an d m u lt iple layers of su bdu ral h em atom a (SDH) of d i eren t ages or den sit ies m ay p ose a ch allenge. Bur h ole drain age or cran iotom y sh ould be con sidered in th is set t ing.
Preprocedure Considerations Radiographic Imaging (Figs. 2.1, 2.2, and 2.3) • X-ray: In gen eral, X-ray is a poor diagn ost ic tool for CSDH. •
Occasion ally, a p lain lm of th e sku ll m ay reveal a calci ed CSDH.15 CT: CT is t h e gold -st an dard im agin g m odalit y for d iagn osin g CSDH. SDHs classically d e m on st rate a crescen t ic con gu rat ion , as t h e ir d ist r ibu t ion over t h e cor t ical convexit y is n ot b ou n d ed by su t u re lin es (in con t rast to e p id u ral b lee d s). Mass e ect , cor t ical b u cklin g, an d m id lin e sh ift m ay also
2
•
Fig. 2.1 Patient with subacute subdural hematoma with a so-called “hematocrit” e ect with blood of di erent densities layering in a dependent fashion. There is mass e ect causing mild shift and left ventricular e acement. This patient was deemed a good candidate for bur hole drainage.
ap p ear d ep e n d in g on t h e t h ickn ess an d size of t h e clot . Th e ap p earan ce of blood on CT scan w ill ch an ge ove r t im e as t h e blood p rod u ct s age (Table 2 .1); su bacu te blood ap p ears isod e n se an d ch ron ic blood , h yp od en se relat ive to brain . Th e d egree of m id lin e sh ift an d t h ickn ess of su bd u ral blood are u sefu l rad iograp h ic m arke rs to assist clin ical d e cision
Chronic Subdural Hem atom as
m akin g regard in g op erat ive in te r ve n t ion . Non con t rast CT u su ally is ad e qu ate to assess t h e age of t h e blood p resen t , an d t h erefore, t h e likelih ood t h at it w ill be d rain ed su ccessfu lly via m in im ally invasive or op e n m ean s. Con t rast -en h an ce d im agin g sh ou ld be con sid ere d if t h e re is con cer n for su bd u ral e m pyem a or for clar it y in t h e set t in g of a su bacu te su bd u ral h em atom a t h at is isod en se w it h resp e ct to t h e b rain t issu e. En h an cem e n t of cor t ical vein s h elp s to d e n e t h e bou n dar y bet w ee n cor tex an d h em atom a. Con t rast m ay also d em on st rate t h e p rese n ce of m e m b ran es. MRI: Magn et ic reson an ce im aging (MRI) is sim ilarly sen sit ive an d sp eci c for diagn osing CSDH as CT scan ; it is p o ten t ially m ore sen sit ive in determ in ing size an d in ter n al st r u ct u re.16 CT gen erally is p referred d u e to th e h igh cost of MR im aging as w ell as th e t im e requ ired to p erfor m t h e st u dy. Sim ilarly to CT scan n ing, th e ap p earan ce of su bd u ral blood w ill also ch ange over t im e (Table 2.2). MRI m ay be con sid ered for m ore det ailed evalu at ion of m em bran es an d layers if th ere is con cern regard ing th e feasibilit y of cat h eter d rain age.
Medications • In t raven ou s (IV) an t ibiot ics sh ou ld be given w ith in 1 h ou r
• •
p rior to in cision . Th e u se of prophylaxis in th e set t ing of m in im ally invasive bedside p rocedu res is left to th e discret ion of th e su rgeon . An t iepilept ic drug prophylaxis sh ould be adm in istered. Sedat ion for bed side procedu res sh ou ld be adm in istered w ith caut ion . Min im ize dosing or avoid sedat ion , if possible, as pat ien t s w ith CSDH m ay be par t icularly sen sit ive to its e ects. On e of th e ben e ts of th e bedside SDH drain age p rocedu re is th e possibilit y to w it n ess rapid n eu rologic im p rovem en t
a
b Fig. 2.2a, b Large right frontoparietal subdural hematoma causing mass e ect and right ventricular e acement. There are some septations within the mixed densit y subdural. A small craniotomy was chosen to evacuate the collection.
17
I Cerebral Traum a and Stroke w h en m in im al or n o sedat ing m edicat ion s are used. Th is st an ds in con t rast to th e d elayed em ergen ce som e (often elderly) pat ien t s exp erien ce after bur h ole drain age u n der gen eral an esth esia. Bu r h ole p roced u res in th e op erat ing room can be perform ed u n der con scious sedat ion or gen eral an esth esia as p er su rgeon p referen ce or pat ien t toleran ce. Cran iotom ies t yp ically are p erform ed u n d er gen eral an esth esia.
Operative Field Preparation • Th e h air overlying th e a ected h em isph ere is clipped w ith • • •
Fig. 2.3 CT scan of a patient’s head with a homogenous right hemispheric subdural hematoma and right to left midline shift. This case was selected for t wist drill craniostomy.
Table 2.1 CT appearance of subdural blood over time 17
18
Time
Appearance relative to brain parenchyma
Hyperacute (, 24 hours) Acute (1–2 days) Subacute (2–13 days) Chronic (. 14 days)
Hypo-/isodense Hyperdense Isodense Hypodense
elect ric clippers. Sterile skin prep arat ion is perform ed w ith p ovidon e iodin e or ch lorh exidin e. Th e plan n ed in cision sites are in lt rated w ith 1% lidocain e w ith 1:100,000 epin eph rin e. Available im aging sh ou ld be st u died carefu lly to determ in e th e ideal en t r y poin t for th e t w ist drill cran iostom y. Th e target is alm ost alw ays m ore lateral th an th e t ypical in sert ion site for a ven t ricu lostom y or in t racran ial pressure (ICP) m on itor.
Table 2.2 MR appearance of subdural blood over time 18 Time Hyperacute (, 24 hours) Acute (1–3 days) Early subacute (3–7 days) Late subacute (8–13 days) Chronic (. 14 days)
T1
T2
Hypo-/isointense Hypo-/isointense Hyperintense Hyperintense Hypointense
Hyperintense Hypointense Hypointense Hyperintense Hyptointense
2
Chronic Subdural Hem atom as
Operative Procedure Bur Hole Drainage Positioning and Skin Incision (Fig. 2.4a, b)
b
a
Figure
Procedural Steps
Pearls
Fig. 2.4
The patient is positioned supine on a donut or a horseshoe, w ith the head rotated approximately 30 degrees to the contralateral side. A shoulder roll is placed longitudinally beneath the ipsilateral shoulder. The back of the bed is elevated slightly.
• For bilateral procedures, the head is kept in
Bur Holes (Right) Tw o incisions—each approximately 3 cm in length—are planned along a line that bisects the interval betw een midline and superior temporal line. The anterior incision is positioned just anterior to coronal suture and the posterior incision, over the parietal eminence. Small Craniotomy (Left) A “lazy ‘S’” incision is begun from approximately 1 cm below the superior temporal line extending superiorly approximately 2 cm lateral to the midline in the parietal region approximately 1 cm posterior to the coronal suture. The incision can be further tailored to the location and size of the hematoma.
•
•
a neutral position. Trace out a reverse question m ark–t ype incision over the a ected hem isphere. This will facilitate a m ore extensive opening, if necessary. The planned bur hole incision sites should fall along the superior lim b of the question m ark. If the CT appearance of the extra-axial uid is both hypodense and homogeneous, it m ay be possible to drain the collection through a single bur hole.
19
I Cerebral Traum a and Stroke
Incisions and Bur Holes/Craniotomy (Fig. 2.5)
20
Figure
Procedural Steps
Fig. 2.5
A no. 10 blade is used to open each incision to the level of pericranium. The pericranium is opened w ith Bovie electrocautery and sw ept to either side w ith a periosteal elevator. For the craniotomy, scalp clips are applied to the scalp edges. The temporalis is incised and is re ected w ith the skin incision. Self-retaining retractors are placed.
Pearls
Bur Holes (Right) Place a single bur hole at each incision site, using a round or matchstick bur, perforator, or acorn drill. Apply bone w ax to the bony edges as necessary.
• Bur Holes ◦ Bur holes should be 1.5 to 2 cm
Small Craniotomy (Left) • Place bur holes at the apices of the exposed calvarium. A footplate attachment, dental tool, or Pen eld no. 3 is used to free the underlying dura from the bone. Use the craniotome to create a small bone ap, limited to the size of the opening. • The craniotome is used to create a roughly ovoid ap. The bone is elevated—using a blunt surgical tool to dissect any remaining dural attachments to the undersurface of the bone—and set aside in antibiotic solution.
• Craniotomy ◦ Resistance m ay be encountered
in diam eter.
◦
at the level of coronal suture, where the dura is more rm ly adherent to bone. The bone ap will be 4 to 5 cm in diam eter.
2
Chronic Subdural Hem atom as
Dural Opening (Fig. 2.6)
Figure
Procedural Steps
Pearls
Fig. 2.6
Bur Holes (Right) • Coagulate the exposed dura w ith bipolar electrocautery at each bur hole site. • Open the dura in a cruciate fashion w ith a no. 11 blade. Coagulate the dural lea ets w ith bipolar electrocautery to prevent bleeding into the subdural space and to ensure opening of the dura across the full surface area of the bur hole. • Upon opening the dura, there may be immediate expulsion of liquid hematoma. If not, a membrane is likely present. The membrane should be coagulated w ith bipolar electrocautery and opened sharply w ith a no. 11 blade.
• Bur Holes ◦ The posterior site should be
Small Craniotomy (Left) • Drill holes circumferentially at the periphery of the craniotomy site. Line the edges of the craniotomy site w ith thin strips of gelatin sponge soaked in thrombin. Place epidural tacking stitches circumferentially w ith 4-0 braided nylon sutures. • Open the dura in a cruciate fashion, w ith a no. 11 blade, follow ed by tenotomy scissors. • An outer membrane may be present upon opening of the dura. Usually, it is possible to develop a distinct plane betw een the undersurface of the dura and the membrane, using a dissector and cotton patties. • Re ect the resulting dural aps to each quadrant and secure them w ith 4-0 braided nylon sutures.
• Craniotomy ◦ When subdural hem atom a is
◦
◦
◦
opened rst to encourage gravitational drainage. At tach one suction unit to a Luken’s trap prior to opening the dura in order to facilitate collection of a specimen for pathology.
present, the dura will have a bluish hue. A 4-0 silk suture, passed through the periosteal dural layer, m ay be used to lift the dura away from the underlying structures to facilitate opening. The subdural m em brane often has a brown-green hue.
21
I Cerebral Traum a and Stroke
Hematoma Evacuation (Fig. 2.7)
22
2
Chronic Subdural Hem atom as
Figure
Procedural Steps
Pearls
Fig. 2.7
Bur Holes (Right) • Once the initial egress of uid subsides, inspect each bur hole site. • Provided the brain has not expanded to ll the subdural space, a small red rubber catheter may be introduced—under direct vision. • Gravity irrigation may be performed w ith lukew arm saline. A x a 10- to 20-mL syringe—w ith the plunger removed—to the open end of the red rubber catheter. Elevate the syringe, ll the open end w ith irrigation, and allow it to funnel through the catheter, into the subdural space. Monitor the bur hole sites during this process to ensure that there is communication w ithin the subdural space betw een the tw o holes. Alternatively, the surgeon may elect simply to ush irrigate betw een the tw o bur holes. • Reorient the catheter w ithin the subdural space as necessary to permit access to additional hematoma. • Continue irrigation until the returning uid is predominantly clear in all directions.
• Additional holes m ay be placed along the
Small Craniotomy (Left) • Coagulate the surface of the membrane and open it w idely— w ithin the craniotomy eld—w ith the bipolar and scissors. • There w ill be immediate expulsion of liquid hematoma. Collect a specimen in the Luken’s trap for pathology. (Consider taking a specimen of membrane as w ell.) • Use bulb irrigation w ith lukew arm saline to ush additional clot from the subdural space at the periphery of the craniotomy site. Membranes and septations can be broken apart w ith bipolar coagulation. • Irrigation w ith a red rubber catheter in a systematic, circumferential fashion under the craniotomy edge is performed until the returning uid is clear in all directions. • Address bleeding points along the membrane and cortical surface w ith bipolar electrocautery and/or adjuvant hemostatic agents as necessary.
• The m embrane does not need to be cut
•
•
•
• • •
distal 2 to 3 cm of the red rubber catheter, taking care not to sever the tubing. If the uid introduced through one hole does not exit the second hole, there m ay be an additional m em brane that is lim iting com m unication. Halt irrigation and reassess. The red rubber catheter m ay be guided in any direction where there is presum ed to be hem atom a; however, if resistance is encountered, do not force the catheter into position. It is possible for the catheter to penetrate brain parenchym a or to tear a bridging vein, resulting in hem orrhage. If acute hem orrhage is suspected (and the uid does not clear with continued irrigation), consideration m ust be given to conversion from bur holes to a full craniotomy.
beyond the edges of the craniotomy. The vascularized m embrane can bleed, and such bleeding m ay be di cult to control if rem ote from the craniotomy. Craniotomy also facilitates ushing out of m ore organized rests of hem atom a not accessible via bur holes. The inner m em brane, if present, is not stripped from the surface of the brain due to the risk of precipitating cortical bleeding. It is important to control active bleeding. Placing gelatin sponge soaked in thrombin in small pieces or strips along the undersurface of the bone can be helpful in stopping bleeding from membranes in di cult-to-reach areas.
23
I Cerebral Traum a and Stroke
Drain Placement (Fig. 2.8)
24
Figure
Procedural Steps
Pearls
Fig. 2.8
Bur Holes (Right) • A small Jackson-Pratt drain or ventricular catheter may be introduced into the subdural space at the frontal site and advanced, over a Pen eld no. 3, until it is visualized at the parietal bur hole. The drain can be advanced further if no resistance is encountered. • Irrigate the bur holes w ith normal saline (using a syringe w ith an angiocatheter tip) to ush out air w ithin the subdural space. Cover each dural opening w ith a piece of gelatin sponge to prevent further air or blood from entering the subdural space.
• Bur Holes • On occasion, the brain expands to ll the
Small Craniotomy (Left) • A at or soft round small Jackson-Pratt drain is carefully placed in the subdural space under direct visualization w ithout resistance depending on how much brain expansion is encountered. The dura is closed in an interrupted or running fashion. The cavity is irrigated to remove most of the air. Gelatin sponge is placed over the cavity prior to replacing the bone ap to prevent air and blood from getting into the subdural space during closure.
• Craniotomy • Compressed gelatin sponge can be used to
subdural space, leaving lit tle or no room for a drain. In such circum stances, the risk of placing a subdural drain may out weigh the bene ts of ongoing drainage.
•
overlap the craniotomy edges especially if a watertight dural seal cannot be achieved. A subgaleal drain m ay be left in place as needed to help prevent a postoperative subgaleal hem atom a or leakage of subgaleal blood into the subdural space.
2
Chronic Subdural Hem atom as
Closing
• The galea and subcutaneous tissue are approxim ated in an in-
• Su p er cial skin an d su bcu t an eou s bleeding is con t rolled
•
• •
u sing bipolar elect rocauter y. Th e in cision site is irrigated w ith an t im icrobial solut ion . For th e sm all cran iotom y: ◦ Th e bon e ap is secured to th e skull w ith t it an iu m plates an d screw s. Th e su bd u ral drain sh ou ld exit via a bu r h ole. It is som et im es n ecessar y to create a groove (w ith a m atch st ick bu r) on th e u n dersu rface of th e bon e ap —at th e bur h ole site—in order to avoid kin king of th e drain at it s exit site. ◦ Th e tem poralis m uscle, if breach ed, is reapproxim ated u sing 2-0 braided nylon su t ures.
•
• • •
terrupted fashion using inverted 3-0 braided absorbable suture. Th e skin is closed w ith staples or w ith 3-0 nylon su t ures in a ver t ical m at t ress fash ion . A 2-0 braided sut ure is placed in a pursest ring fash ion aroun d th e su bdural drain exit site to an ch or th e drain to th e skin an d seal th e sp ace arou n d th e drain , p reven t ing in adverten t drain rem oval, as w ell as leakage of blood an d/or CSF from th e drain site. A sim ilar sut ure is placed aroun d th e subgaleal drain , if p resen t , at its exit site. Th e skin aroun d th e in cision s is clean ed of all blood products an d su rgical d ebris. A sterile dressing is applied.
25
I Cerebral Traum a and Stroke
Operative Procedure Tw ist Drill Craniostomy Positioning and Skin Incision (Fig. 2.9)
26
Figure
Procedural Steps
Pearls
Fig. 2.9
The patient’s head is positioned on a rm surface, such as a folded blanket or gel donut, and turned 15 to 30 degrees to the contralateral side (60 degrees if a more posterior parietal entry point is required). Make a small stab incision at the desired insertion site w ith a no. 15 blade. The entry point for the catheter insertion is chosen over a relatively thick part of the SDH that is safely accessible, usually in the frontal region, about 2 cm in front of the coronal suture and 4 to 8 cm o midline.
• Soft restraints are often necessary to prevent the
•
patient from inadvertently reaching into the sterile eld. An assistant may be useful to stabilize the patient’s head during the procedure, with hands placed gently on either side of the patient’s jaw, under the drapes. The ideal entry point is usually sim ilar to a ventriculostomy entry point, but m ore lateral. Occasionally, a predom inantly posterior SDH will require a parietal entry point.
2
Chronic Subdural Hem atom as
Drilling (Fig. 2.10a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 2.10
(a) A hand-operated tw ist drill is positioned at the desired entry point and a small hole is drilled through the skull. The tw ist drill can be started in the usual perpendicular angle, but once the hole is started and the drill bit is stable enough in the hole to not slide, the drill angle can be carefully adjusted o the perpendicular angle and into the direction in w hich you w ish the catheter to enter. Usually this means tilting the drill tip posteriorly in order to angle the hole posteriorly, thereby directing the catheter into the subdural space and tow ard the posterior dependent portion of the chronic SDH collection.
• Angling the drill helps to guide the
The dura is usually penetrated w ith the drill bit. Alternatively, a no. 11 blade or spinal needle can be used.
catheter into the subdural space sm oothly, and also helps to avoid inadvertently passing the catheter through the surface of the brain. (b) The “Kindt Drill” t ype of short straight-axis hand drill (Fig. 2.10b) is ideally suited for facilitating precise control of the drill position and angle; this is done by using the dom inant hand to t wist the drill while resting the nondominant hand on the patient’s head to stabilize the drill position and angle.
27
I Cerebral Traum a and Stroke
Catheter Placement (Fig. 2.11a, b)
a
b
28
Figure
Procedural Steps
Pearls
Fig. 2.11
A ventriculostomy-type catheter is inserted through the hole in the skull and the dura and into the subdural space. (a) The w ire stylet is used to advance the catheter through the dura. (b) As soon as the catheter has passed through the dura, the catheter should then be advanced o the stylet and “soft passed” into the subdural space, to minimize the risk of advancing the catheter into the brain parenchyma.
• Choose a ventricular catheter with a larger inner
•
diameter (e.g., 1.5–1.9 m m ) and larger side hole perforations to m axim ize the abilit y to drain thicker CSDH contents. Since the catheter is usually in place for only 12 to 48 hours, the author (ASL) usually does not tunnel the catheter, but som e may prefer to do so.
2
Closing • Th e in sert ion site is closed aroun d th e cath eter w ith 3-0 •
•
m on o lam en t nylon su t u res, w h ich are also u sed to an ch or th e cath eter in place. Sin ce th e cath eter is usu ally in p lace for on ly 12 to 48 h ou rs, th e au th or (ASL) prefers to place a closing st itch w h ere th e cath eter exit s (w h ile th e site is st ill an esth et ized), so th at it can be easily closed w h en th e cath eter is rem oved, w ith out th e n eed for open ing an oth er su t u re an d n eedle h older. Tip: Place th is st itch prior to th e an ch oring st itch so you can m ove th e cath eter aside an d p osit ion th e st itch w h ere th e cath eter w ill be on ce it rela xes back in to posit ion . Th row a su rgeon’s kn ot (t w o overh an d th row s in th e sam e d irect ion ) w ith ou t pu lling it t igh t , so th at th e sut ure w ill st ay in place, an d you can easily p u ll it t igh t on ce th e cath eter is rem oved (Fig. 2.12). Dress th e site w ith a dr y gau ze dressing an d a h ead w rap. Th e lat ter provides a secure dressing w ith w h ich to an ch or th e extern al drain age t ubing. A com plex extern al ven t ricular drain system is n ot required sin ce ICP w ill n ot be m easured; a sim ple drain age collect ion bag is su cien t .
Postoperative Management Monitoring • Pat ien t s are m on itored in an in ten sive care u n it to obser ve for
• • •
ch anges in n eurologic st at us an d h em odyn am ic param eters. ◦ Seizu re act ivit y an d p ostop erat ive re-bleed are th e t w o m ost com m on com p licat ion s. Pat ien t s are m ain t ain ed relat ively at in bed (0–20 degrees) u n t il th e drain s are rem oved . Drains are rem oved in a sterile fashion, usually w ithin 48 hours. ◦ All drain sites m ust be closed t ightly using 3-0 nylon su t ures to preven t egress of CSF an d/or en t r y of air. Skin st ap les or su t u res are rem oved after 1 to 2 w eeks.
Tw ist Drill Craniostomy • Th e pat ien t is m on itored in th e in ten sive care un it , w ith •
•
•
•
Fig. 2.12 The closing stitch. A suture is placed in position to serve as a closing suture for after the catheter is removed. A surgeon’s knot (t wo overhand throws in the same direction) is placed but not pulled tight until after the catheter is removed, usually the next day.
Chronic Subdural Hem atom as
h ou rly n eu rologic ch ecks as long as th e d rain is in p lace, an d u sually for 12 to 24 h ou rs after th e drain is discon t in u ed. Th e h ead of th e bed is kept at to prom ote gravit y drain age of th e SDH, an d to avoid n egat ive pressure aspirat ion of air back in to th e su bdural space. Th e pat ien t can be log rolled side-tosid e. Ch anges in p osit ion m ay act u ally facilit ate drain age of th e SDH. Th e pat ien t can be allow ed to raise th e h ead of th e bed to 10 to 15 degrees for eat ing, if n eurologically in dicated. Th e drain is placed to gravit y drain age, st art ing at or just below th e pat ien t’s ear (Fig. 2.13a), an d th e level is adjusted to m ain t ain a steady drain age rate. It w ill becom e n ecessar y to low er th e drain gradually (over several m in utes to several h ou rs) as th e p ressu re in th e su bdu ral sp ace decreases (Fig. 2.13b). Th e auth or (ASL) prefers to adjust th e drain level in order to m ain t ain an SDH drain age rate of app roxim ately 1 drop of SDH u id per secon d . Th is gives th e n u rses a clear object ive goal in order to m ake safe an d app rop riate adju st m en ts to th e drain level, an d resu lts in a slow, gradu al evacu at ion of th e SDH. Pat ien t s seem to bet ter tolerate slow drain age of th e SDH, w ith decreased risk of h eadach e, n au sea, n eu rologic d eteriorat ion , or con t ralateral h em orrh age. Th e drain age collect ion bag w ill en d up at or n ear oor level as th e last of th e SDH is drain ed; th e rate w ill d ecrease below 1 drop per secon d an d, ult im ately, stop. W h en th e SDH drain age h as ceased or slow ed sign i can tly, an d follow -u p CT dem on st rates ad equ ate drain age of th e SDH (u sually 50–90%), th e drain is rem oved. Th e skin is prepared in a sterile fash ion . Th e cath eter-an ch oring sut u re is cu t free from th e cath eter an d th e cath eter is rem oved, bu t th e st itch itself is left in place in th e skin to keep th at part of th e in cision closed. Th e previously placed closing sut u re is t ied t igh tly to com plete th e closure of th e exit site. In rare cases, xan th och rom ic-app earing CSF m ay con t in u e to drain in de n itely. Th e drain sh ould be discon t in ued after 2 to 4 days, regardless of th e volum e of con t in u ed drain age, an d follow -u p im aging w ill be requ ired to determ in e if any addit ion al th erapy is in dicated. Usually th e rem ain ing subdural u id w ill resolve sp on t an eou sly over t im e (w eeks to m on th s), an d a su bdu ral sh u n t is ver y rarely requ ired.
29
I Cerebral Traum a and Stroke
b
a Fig. 2.13a, b (a) The drain collection bag is initially leveled with the drip chamber “0” mark at or just below the level of the patient’s ear. Note the approximately 20-mL chronic subdural hematoma uid already in the drip chamber. (b) As more SDH is evacuated, and the pressure decreases in the subdural space, the drip chamber is gradually lowered.
Medication • An t iconvu lsan ts are adm in istered for a tot al of 7 days. • For cran iotom ies an d bu r h oles, an t ibiot ics are con t in ued for • •
24 h ou rs postoperat ively. Dexam eth ason e, in a 2-w eek tapering dose, m ay be u sed if m ild exp an sion of th e residu al collect ion is n oted in th e postoperat ive period. It is recom m en ded th at p at ien t s rem ain o an t icoagu lan t/ an t iplatelet agen ts u n t il th e residu al su bdu ral collect ion s resolve.
Radiographic Imaging • A postop erat ive CT scan is perform ed to evalu ate th e exten t
• • •
30
of subdural h em atom a evacuat ion , as w ell as to exclude n ew postoperat ive subdural or epidural h em orrh age (Figs. 2.14 an d 2.15). For t w ist drill cran iostom ies, on ce SDH drain age h as slow ed or ceased, a follow -up CT scan of th e h ead is obt ain ed (usually th e n ext m orn ing) (Fig. 2.16). Con sider a repeat CT scan about 3 days after drain rem oval to evaluate for reaccum ulat ion . Barring a ch ange in n eu rologic st at us, addit ion al CT scan s are u su ally obtain ed at 2 to 4 w eeks, 2 to 3 m on th s, an d th en as n eeded u n t il th e SDH is com pletely resolved.
Fig. 2.14 Postoperative CT scan of the patient in Fig. 2.1 undergoing bur hole drainage with drain in place. There is pneumocephalus and improvement in m ass e ect. The patient also has a smaller subacute right parietal subdural collection which was treated conservatively.
2
Chronic Subdural Hem atom as
a
b Fig. 2.15a, b (a) Postoperative CT of patient in Fig. 2.2 undergoing craniotomy for subdural evacuation. There is a Jackson-Prat t drain in the subdural space and mild pneumocephalus with improvement in mass e ect. (b) Delayed scanning after drain removal revealed further decrease in the residual collection.
Special Considerations Su bdu ral reaccu m u lat ion is a kn ow n risk of op erat ive t reatm en t . Reop erat ion m ay be n ecessar y. A secon d reaccu m u lat ion m ay requ ire su bd u ral–periton eal sh u n t ing (w ith ou t a valve), w h ich m ost often resolves th is di cult problem .
W h ile the focus of th is chapter does n ot in clude the m edical t reat m ent of subacute an d chron ic subdural h em atom as, it is w orth m en t ion ing th e u se of cort icosteroids as an adju n ct to surger y. Th e rat ion ale for th e u se of cort icosteroids is based on the ant iangiogenic propert ies an d inh ibit ion of the in am m ator y react ion , presum ed to play a key role in h em atom a form at ion an d m ain ten an ce.1,2 Five obser vat ion al st u dies p rovide class III eviden ce th at suggests th at t reat m en t w ith cort icosteroids for CSDH m igh t be as safe an d e ect ive as su rger y, an d th erefore ben e cial in th e t reat m en t of CSDH.3 How ever, n o ran dom ized con t rolled t rials exam ining th e use of cort icosteroids for this in dicat ion have been publish ed. Prim ar y t reat m en t w ith an oral an t i brin olyt ic, t ran exam ic acid, h as been dem on st rated to be e ect ive in a sm all series.12 A su bd u ral su ct ion evacu at ion system is com m ercially available. Th is m in im ally invasive ap p roach h as in d icat ion s sim ilar to t h e t w ist d r ill cran iotostom y, bu t d oes n ot involve p lacem en t of d evices w it h in t h e in t racran ial cavit y. Th e kit con t ain s d et ailed in st r u ct ion s regard in g it s u se an d in ser t ion . Th is tech n iqu e p rovid es yet an ot h er opt ion in t h e m an agem en t of p at ien t s w it h CSDH an d o ers t h e p ossibilit y of im m ediate relief of p ressu re if a p at ien t becom es severely let h argic or obt u n d ed .
References Fig. 2.16 Post-drainage CT of patient in Fig. 2.3 shows a signi cant decrease in the size of the chronic subdural hematoma, and decreased midline shift. The tip of the subdural catheter can be seen in the subdural space (arrow).
1. Nat ion al Neu rosu rgical Procedu ral St at ist ics. Rolling Meadow s, IL: Am erican Associat ion of Neu rological Su rgeon s; 2006 2. Mori K, Maeda M. Su rgical t reat m en t of ch ron ic su bdu ral h em atom a in 500 con secu t ive cases: clin ical ch aracterist ics, surgical ou tcom e, com plicat ions, an d recurrence rate. Neurol Med Ch ir 2011;41(8):371–381
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I Cerebral Traum a and Stroke 3. Hirakaw a T, Hash izu m e K, Fu ch in ou e T, Takah ash i H, Nom u ra K. St at ist ical an alysis of chron ic subdu ral h em atom a in 309 adu lt cases. Neurol Med Ch ir 1972;12(0):71–83 4. Kaw am at a T, Takesh ita M, Ku bo O, Izaw a M, Kagaw a M, Takaku ra K. Man agem en t of in t racran ial h em orrh age associated w ith an t icoagulan t th erapy. Surg Neurol 1995;44(5):438–442 5. Robin son RG. Ch ron ic su bdu ral h em atom a: su rgical m an agem en t in 133 pat ien t s. J Neurosurg 1984;61(2):263–268 6. Miran da LB, Braxton E, Hobbs J, Qu igley MR. Ch ron ic su bdu ral h em atom a in th e elderly: n ot a ben ign disease. J Neurosurg 2011;114(1):72–76 7. Ram ach an d ran R, Hegd e T. Ch ron ic su bdu ral h em atom as—cau ses of m orbidit y an d m ort alit y. Surg Neurol 2007;67(4):367–372 8. Shono T, Inam ura T, Morioka T, Matsum oto K, Suzuki SO, Ikezaki K, Iw aki T, Fukui M. Vascular endothelial grow th factor in chronic subdural haem atom as. J Clin Neurosci 2001;8(5):411–415 9. Santarius T, Kirkpatrick PJ, Ganesan D, et al. Use of drains versus no drains after bur-hole evacuat ion of chronic subdural hem atom a: a random ized controlled trial. Lancet 2009;374(9695):1067–1073 10. Delgado-Lop ez PD, Mar t in -Velasco V, Cast illa-Diez JM, et al. Dexam eth ason e t reat m en t of ch ron ic su bdu ral h em atom a. Neuroch irugia (Ast ur) 2009;20:346–359 11. Su n TF, Boet R, Poon WS. Non -su rgical p rim ar y t reat m en t of ch ron ic subdural h em atom a: prelim inar y result s of using dexam eth ason e. Br J Neu rosu rg 2005;19:327–333
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12. Kageyam a H, Toyooka T, Tsu zu ki N, Oka K. Non su rgical t reat m en t of ch ron ic subdu ral h em atom a w ith t ran exam ic acid. J Neurosurg 2012;119:331–337 13. Takayam a M, Ter u i K, Oiw a Y. Ret rospect ive st at ist ical an alysis of clinical factors of recurren ce in ch ron ic subdural h em atom a: correlat ion bet w een un ivariate an d m u lt ivariate an alysis. No Sh in kei Geka 2012;40(10):871–876 1 4 . St an išić M, Hald J, Rasm u sse n IA, et al. Volu m e an d d e n sit ies of ch ron ic su bd u ral h ae m at om a obt ain e d from CT im agin g as p re d ict ors of p ostop e rat ive re cu r re n ce: a p rosp ect ive st u d y of 1 0 7 op e rat e d p at ie n t s. Act a Ne u roch ir 2 0 1 3;1 5 5 (2 ): 323–333 15. Pap p am ikail L, Rato R, Novais G, Bern ardo E. Ch ron ic calci ed subdural h em atom a: Case repor t an d review of the literat ure. Surg Neu rol Int 2013;4:21 1 6 . Se n t u rk S, Gu zel A, Bilici A, Takm a z I, Gu zek E, Alu clu U, Ceviz A. CT an d MR im agin g of ch ron ic su b d u ral h ae m ato m as: a com p arat ive st u dy. Sw iss Me d W kly 2010;140(23-24): 335–340 17. Coh n DF, Avrah am i E, Ried er- Grossw asser I. Radiograp h ic isoden se subdural h em atom as in com puterized tom ography. Sch w eiz Med Woch ensch r 1981;111(12):427–429 18. Tu rh im S. In t racerebral h em orrh age. In : Fron tera JA, ed. Decision Making in Neurocrit ical Care. New York: Th iem e Medical Publish ers; 2009:36–52
3
Surgery for Cerebral Contusions of the Frontal and Temporal Lobes, Including Lobar Resections Pal S. Randhaw a and Craig Rabb
Introduction Cerebral con t usion s are obser ved in up to 8.2% of all t raum at ic brain injuries 1,2 an d are m ore com m on (13–35% of pat ien ts) in th e set t ing of severe t raum at ic brain injur y.1,3–7 W h ile con t usion s can occu r in alm ost any lobe, m ost occu r in th e fron t al an d tem poral lobes.8,9 Most sm all lesion s w ill n ot require su rgical in ter ven t ion 1,3,10,11 ; th e m ajorit y w ill reabsorb in 4 to 6 w eeks.
Indications • Guidelin es m ay assist clin ical decision m aking w ith respect •
to w h ich con t u sion s m igh t requ ire su rgical in ter ven t ion .1 Operat ive in ter ven t ion is in dicated in th e set t ing of: ◦ A fron t al or tem p oral con t u sion of greater th an 20 cm 3 in volu m e an d associated w ith any of th e follow ing: ▪ Glasgow Com a Scale (GCS) score 6 to 8 ▪ Midlin e sh ift at least 5 m m ▪ Cistern al com pression
◦ Any lesion calculated to be greater th an 50 cm 3 in volu m e ◦ A paren chym al m ass lesion th at is associated w ith : ▪ Progressive n eurologic declin e at t ribut able to th e lesion ▪ Refractor y in t racran ial hyperten sion ▪ Mass e ect on com p u ted tom ograp hy (CT) scan ◦ A tem poral lobe h em atom a greater th an 30 m L, w ith or w ith out any m idlin e sh ift or elevat ion of th e m iddle cerebral arter y. Th ese pat ien t s are part icularly at risk for t ran sten torial h ern iat ion given th e lim ited space of th e m idd le cran ial fossa.
Preprocedure Considerations Radiographic Imaging Non con t rast h ead CT is vit al in th e evalu at ion of all severe t raum at ic brain injuries. CT allow s for an atom ic localizat ion of su rgical path ology an d, in t u rn , facilitates p lan n ing of p at ien t posit ion ing an d operat ive approach . • Pre o pe rative im aging (Fig 3.1).
b
a Fig. 3.1a, b Axial CT images demonstrating (a) frontal and (b) temporal lobe cerebral contusions.
33
I Cerebral Traum a and Stroke
Medication
Choice of Surgical Approach
• Th e au t h ors p refer t h e u se of van com ycin for an t ibiot ic
• Tw o di eren t approach es—bicoron al an d m odi ed pterion al—
p rop hyla xis, p rovid ed t h e p at ien t d oes n ot h ave ren al failu re or any ot h er con t rain d icat ion s. Given t h e in creasin g p revalen ce of m et h icillin -resist an t Staphylococcus aureus, it is p ossible t h at t h e skin can or w ill be colon ized by t h is m icroorgan ism . An t ie p ile p t ic p rop h yla xis sh ou ld be p rovid e d . Fosp h e nyt oin m ay b e a d m in ist e re d in a loa d in g d ose of 1 7 t o 2 0 m g p h e n yt oin e qu ivale n t s (PE)/kg in n on a lle r gic p at ie n t s w h o are n ot on st a n d in g a n t ie p ile p t ic m e d icat ion ; a lt e r n at ely, levet ira cet a m m ay b e ad m in ist e re d at a load in g d ose of 2 0 m g/kg.
are ou tlin ed in th e Operat ive Procedu re sect ion ; th e ch oice of ap p roach w ill dep en d on th e site of th e path ology. Bilateral or un ilateral, m ed ial con t u sion s of th e fron tal lobes m ay be add ressed opt im ally by a bicoron al ap p roach . A far lateral fron tal con t usion m ay be approach ed by a m odied pterion al ap proach . Tem poral con t usion s gen erally can be approach ed via a m odi ed pterion al approach .
•
• • •
Operative Field Preparation • Alcoh ol prep is perform ed before th e applicat ion of povidone •
34
iodin e or ch lorh exidin e. Th e plan n ed in cision s are m arked an d in lt rated w ith 1% lidocain e w ith 1:100,000 epin eph rin e.
3
Surgery for Cerebral Contusions of the Front al and Tem poral Lobes
Operative Procedure Bicoronal Approach Positioning (Fig. 3.2)
Figure
Procedural Steps
Pearls
Fig. 3.2
The patient is positioned supine, w ith the head in a neutral, upright position. The head is stabilized w ith May eld three -point xation. The head of bed is elevated slightly.
• Consider using a horseshoe headrest to facilitate m ore rapid decompression in the em ergency set ting, or if a skull fracture prevents use of a May eld three-point xation.
35
I Cerebral Traum a and Stroke
Skin Incision (Fig. 3.3)
Figure
Procedural Steps
Pearls
Fig. 3.3
Mark out a bicoronal incision, starting at the level of zygoma and extending superiorly tow ard the midline, just posterior to the hairline. Carry the incision across midline, in a mirror fashion, to the contralateral zygoma.
• Scalp clips are applied to the skin
Initiate the skin opening w ith a no. 10 blade. Carry the incision dow n to the pericranium above the superior temporal line and dow n to the temporalis fascia in the temporal region.
36
edges to assist hemostasis.
3
Surgery for Cerebral Contusions of the Front al and Tem poral Lobes
Subcutaneous Dissection (Fig. 3.4)
Figure
Procedural Steps
Pearls
Fig. 3.4
The pericranium is opened w ith monopolar electrocautery, in line w ith the scalp incision. The super cial temporal fascia and temporalis muscle are opened, likew ise, using monopolar electrocautery. Pericranium and muscle are advanced w ith a combination of periosteal elevator and monopolar electrocautery. Leave the frontalis muscle intact if possible.
• Special care m ust be taken to avoid
• The myocutaneous ap is re ected anteriorly until the anterior middle fossa and supraorbital areas are accessible. The ap is secured w ith mini-tow el clips, hooks, or suture.
comprom ising the frontalis branch of the facial nerve. Rem ain above the zygom a when approaching the inferior aspect of the incision. A few rolled sponges are placed beneath the ap as it is re ected and secured.
37
I Cerebral Traum a and Stroke
Bur Hole Placement (Fig. 3.5)
38
Figure
Procedural Steps
Pearls
Fig. 3.5
Bur holes are placed w ith a high-speed drill at the follow ing sites: just above the root of zygoma; at the keyhole ; and just above superior temporal line, anterior to coronal suture. An additional pair of holes are placed straddling the midline, anterior to coronal suture. The base of each hole is cleared w ith a curette. The dura is stripped from the undersurface of the bone, locally and betw een each pair of holes, w ith a separator (e.g., Pen eld no. 3, Hoen, or similar).
• Exercise particular care when stripping the dural at tachments bet ween the t wo param edian holes overlying the sagit tal sinus.
3
Surgery for Cerebral Contusions of the Front al and Tem poral Lobes
Craniotomy (Fig. 3.6)
Figure
Procedural Steps
Fig. 3.6
The craniotome is used to connect each pair of bur holes circumferentially, taking care to stay low in the frontal and temporal regions and making the nal cut in the region of the superior sagittal sinus. The bone ap is carefully elevated aw ay from the underlying dura and set aside in antibiotic solution. Bone w ax is applied to the bony edges w here necessary. Bleeding along the midline sagittal sinus may be controlled w ith a combination of brillar hemostatic material, thrombin-soaked gelatin sponge, and hemostatic matrix sealant. If all other measures fail, the superior sagittal sinus may be ligated anteriorly, at the level of the crista galli.
39
I Cerebral Traum a and Stroke
Dural Opening (Fig. 3.7a–c)
a
c
b
Figure
Procedural Steps
Pearls
Fig. 3.7
Pilot holes are drilled circumferentially at the periphery of the craniotomy to create dural tack-up sites.
• Dural tacking stitches help prevent the formation of postoperative epidural hematomas. However, do not take time at this point in the procedure to place the actual stitches.
(a) The dural opening is initiated w ith a no. 15 blade and enlarged w ith tenotomy scissors. A strip of moistened nonadherent bandage or a cotton pattie may be introduced into the subdural space to protect the underlying cortex. A trap-door type opening ( apped tow ard the midline) provides w ide access to the frontal lobe. If access to the temporal fossa is necessary and/or ligation of the sagittal sinus anticipated, dural slits are made initially parallel to the anterior portion of the sinus and the dural opening extending laterally and inferiorly tow ard the middle fossa on either side. The dural aps are secured under modest tension w ith 4-0 braided nylon stitches.
40
(b) It may be necessary to divide the superior sagittal sinus and falx in order to achieve adequate decompression of the frontal lobes. After release of the sinus, use a double ligature technique to occlude the sinus, using a 2-0 polypropylene or nylon suture. Make a double circular course across the falx, just below the level of the sinus, and cinched tightly to occlude the sinus. Repeat this process w ith a second stitch, anterior to the rst.
• The sinus should be targeted for ligation and
(c) Sever the sinus between the ligatures and divide the subadjacent falx in its entirety to complete the exposure.
• Alternatively, ligation may be performed with
•
division at a point well forward of the coronal suture (along the anterior one-third of the sinus). The second needle pass should be m ore super cial (within the falx) than the rst.
a hemostatic double surgical clip at the inferior insertion of the sinus into the falx, near the crista galli. At tention must be paid to ensure that the clips cross the sinus completely.
3
Surgery for Cerebral Contusions of the Front al and Tem poral Lobes
Address the Contusion (Fig. 3.8a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 3.8
(a) Inspect the cortical surface. Select your site for entry—an area of obvious contusion or cortical disruption is ideal.
• If the cortical surface appears undisturbed, consider
Cauterize the super cial vessels and pia mater at the planned entry site. Use a no. 11 or no. 15 blade to open the pia. Approach the hematoma cavity in the subpial plane w ith a combination of gentle suction and bipolar electrocautery.
•
(b) Upon entry to the hematoma, suction out any liquid clot and remove solid clot in a piecemeal fashion. Continue evacuation of hematoma until gliotic brain is visible on all sides.
•
the use of ultrasound to localize the m ost super cial extent of the hem atom a. A handheld m alleable retractor—introduced over a saline-moistened 1- 3 3-cm cot ton pat tie (to protect the friable tissue along the cavit y wall)—m ay assist visualization during contusion resection and hem ostasis. Always be mindful of position relative to the anterior horn of the lateral ventricular while evacuating hem atom a from deep subcortical spaces. Avoid entry to the ventricle if feasible.
41
I Cerebral Traum a and Stroke
Anterior Frontal Lobectomy (Fig. 3.9)
42
Figure
Procedural Steps
Pearls
Fig. 3.9
In the event that the frontal lobe is extensively contused, consideration may be given to a frontal lobectomy. The margin of resection w ill depend on the size and appearance of contused frontal lobe. Alternatively, if contusion is di use, one may begin the cortical incision 7 to 8 cm from the frontal pole and extend laterally to the level of the lesser w ing of the sphenoid. If it is desired to avoid entry into the lateral ventricle, the medial aspect of the cortical incision should be made w here the tw o frontal lobes are clearly separate.
• In the set ting of signi cant intraoperative or anticipated postoperative swelling, consider frontal polectomy to ensure adequate decompression.
3
Surgery for Cerebral Contusions of the Front al and Tem poral Lobes
Modi ed Pterional Approach Positioning (Fig. 3.10)
Figure
Procedural Steps
Pearls
Fig. 3.10
The patient is placed on the table in a supine position. The head is turned 60 to 90 degrees aw ay from the side of the approach to help provide better surgical visualization. A roll is placed longitudinally beneath the ipsilateral shoulder. The head is stabilized w ith a three -pinion head holder.
• If the cervical spine has not been cleared, m aintain
•
the rigid collar and rotate head and body as a unit (a larger shoulder roll m ay be necessary) to provide the necessary exposure. A horseshoe headrest may decrease tim e to decompression in the em ergent set ting.
43
I Cerebral Traum a and Stroke
Skin Incision (Fig. 3.11)
Figure
Procedural Steps
Pearls
Fig. 3.11
Hair is clipped with an electric razor over the hemicranium of interest.
• Preserve the frontalis branch of the
A reverse question mark–type incision (i.e., trauma ap) is planned, starting 1 cm anterior to the external auditory meatus and within 1 cm of the superior aspect of the zygoma, extending posteriorly toward the parietal eminence and curving superiorly toward the midline, ending just behind the hair line. The incision is initiated with a no. 10 blade and carried down to the level of pericranium superiorly and temporalis fascia inferiorly. Scalp clips are applied to the skin edges.
44
facial nerve as well as the m ain trunk of the super cial temporal artery.
3
Surgery for Cerebral Contusions of the Front al and Tem poral Lobes
Subcutaneous Dissection (Fig. 3.12)
Figure
Procedural Steps
Pearls
Fig. 3.12
The pericranium and temporal fascia and muscle are opened in line w ith the scalp incision, using monopolar electrocautery.
• Som e advocate m obilizing the
The resulting myocutaneous ap is dissected subperiosteally and advanced forw ard until the root of zygoma and keyhole are visible. The ap is secured w ith mini tow el clips, hooks, or suture.
temporalis o the superior aspect of the zygom atic arch by approxim ately 1 to 2 cm .
45
I Cerebral Traum a and Stroke
Bur Hole Placement (Fig. 3.13)
46
Figure
Procedural Steps
Fig. 3.13
Bur holes are placed w ith a high-speed drill at the follow ing sites: just above the root of zygoma; at the keyhole ; over the parietal eminence ; and at a point 1 cm lateral to the midline and anterior to coronal suture. The base of each hole is cleared w ith a curette. The dura is stripped from the undersurface of the bone, locally and betw een each pair of holes, w ith a separator (e.g., no. 3 Pen eld, Hoen, or similar).
3
Surgery for Cerebral Contusions of the Front al and Tem poral Lobes
Craniotomy (Fig. 3.14)
Figure
Procedural Steps
Pearls
Fig. 3.14
The craniotome is used to connect each pair of bur holes circumferentially. It may be necessary to thin the bone crossing the sphenoid ridge w ith a bur. A no. 3 Pen eld or small, curved periosteal may be introduced along the posterior margin of the craniotomy to initiate elevation of the bone ap aw ay from the underlying dura. Once removed, the bone ap is set aside in antibiotic solution.
• Temporal exposure m ay be
The dural surface is irrigated. Branches of the middle meningeal artery observed on the exposed dural surface are coagulated w ith bipolar electrocautery.
•
Bone w ax is applied to the bony edges w here necessary.
augm ented by rem oval of additional bone with a Leksell rongeur until ush with the middle fossa oor and anterior temporal dura. Pay particular at tention to any open air cells at the temporal bone m argins. Pack and seal any observed opening.
47
I Cerebral Traum a and Stroke
Dural Opening (Fig. 3.15)
48
Figure
Procedural Steps
Pearls
Fig. 3.15
Pilot holes are drilled circumferentially at the periphery of the craniotomy to create dural tack-up sites.
• Do not take tim e at this point in the procedure to
A reverse C–shaped dural ap (re ected onto the sphenoid ridge) is planned.
•
The dural opening is initiated over the frontal area with a no. 15 blade and enlarged with tenotomy scissors. A strip of moistened nonadherent bandage or a cotton pattie may be introduced into the subdural space to protect the underlying cortex. The dural ap is secured under modest tension with 4-0 braided nylon stitches.
• Allow a dural m argin of at least 0.5 cm with respect •
place the tacking stitches unless active bleeding from the epidural space beneath the bony edge is observed. A ap fashioned in this m anner will maxim ize the vascular supply and, therefore, its viabilit y.
to the craniotomy edge to perm it prim ary closure after decompression. Keep the re ected dural ap m oistened with a damp sponge to minimize shrinkage.
3
Surgery for Cerebral Contusions of the Front al and Tem poral Lobes
Address the Contusion (Fig. 3.16a, b)
b
a
Figure
Procedural Steps
Pearls
Fig. 3.16
(a) Identify the Sylvian ssure. This is best done in relation to the location of the sphenoid ridge. It may be necessary to drill the bone of the sphenoid ridge until ush w ith the anterior and middle fossae to augment the surgical exposure.
• The sphenoid ridge separates the anterior
Inspect the cortical surface. Select your site for entry. An area of obvious contusion or cortical disruption is ideal.
•
Cauterize the super cial vessels and pia mater at the planned entry site. Use a no. 11 or no. 15 blade to open the pia. Approach the hematoma cavity in the subpial plane w ith a combination of gentle suction and bipolar electrocautery.
•
temporal lobe from the adjacent frontal lobe and, in general, serves as a m ore stable landm ark for identifying the Sylvian ssure than does the middle cerebral vein. If the cortical surface appears undisturbed, consider the use of ultrasound to localize the most super cial extent of the hem atom a. A handheld m alleable retractor—introduced over a saline-m oistened 1- 3 3-cm cot ton pat tie (to protect the friable tissue along the cavit y wall)—may assist visualization during contusion resection and hem ostasis.
(b) Upon entry to the hematoma, suction out any liquid clot and remove solid clot in a piecemeal fashion. Continue evacuation of hematoma until gliotic brain is visible on all sides.
49
I Cerebral Traum a and Stroke
Anterior Temporal Lobectomy (Fig. 3.17)
50
Figure
Procedural Steps
Fig. 3.17
In the event that the temporal lobe is severely contused, consideration may be given to an anterior temporal lobectomy. While one may resect up to 5 to 6 cm of the anterior, nondominant temporal lobe—carrying out the resection to the junction of the Rolandic and Sylvian ssures to demarcate the posterior limit of resection (as in tumor cases)—the posterior limit ultimately w ill depend on w hat the surgeon feels necessary for the patient’s survival.
3
Surgery for Cerebral Contusions of the Front al and Tem poral Lobes
Closing • Hem ostasis is at tain ed w ith in th e h em atom a cavit y u sing a
•
•
• • • • •
com binat ion of m ech an ical an d ch em ical tech n iques. Focal bleeding poin ts are con t rolled w ith bipolar elect rocauter y. Tem porar y packing w ith gelat in sponge soaked in th rom bin m ay be augm en ted w ith h em ostat ic m at rix sealan t an d salin e-m oisten ed cot ton p at t ies. Half-st rength hydrogen p eroxide or n orm al salin e-soaked cot ton balls m ay be u sed to t am pon ade gen eralized oozing as w ell. On ce adequate h em ost asis h as been ach ieved, th e w alls of th e h em atom a cavit y are lin ed w ith sm all p ieces of a brillar h em ostat ic m aterial. In th e absen ce of sign i can t sw elling, th e du ra m ay be reap p roxim ated w ith 4-0 braided absorbable or braided nylon su t u res in th e stan dard “w ater-t igh t” fash ion . Th e dural closu re can be su p p lem en ted w ith du ral graft m aterial (eith er au togen ou s or ar t i cial). If th ere is sign i can t sw elling, th e du ra m ay be left open an d a du ral patch graft su t u red to th e m argin s of th e n at ive du ra. Con siderat ion sh ould be given to leaving th e bon e ap out at th e t im e of closure. Pilot holes are drilled at regular in ter vals aroun d th e periph er y of th e craniotom y site. Epidural tacking st itches are placed w ith 4-0 braided nylon sut ures. Th e bon e ap is reapproxim ated w ith a m in i-plate system . Th e tem poralis m uscle is reapproxim ated w ith 2-0 braided absorbable su t u res. Th e galea an d subcutan eous t issue are reapproxim ated w ith 2-0 braided absorbable sut ures in an inverted, in terrupted fash ion . Th e skin is closed eith er w ith staples or w ith 3-0 nylon (in a vert ical m at t ress or ru n n ing fash ion ).
• Bacit racin oin t m en t , w ith a dressing of ch oice, is th en p laced •
over th e in cision site. If th e pat ien t is com atose, a ven t ricu lostom y sh ou ld also be p laced.
Postoperative Management Monitoring • It is th e au th ors’ p ract ice to p lace th e p at ien t in a m on itored
•
set t ing (e.g., th e in ten sive care u n it) overn igh t in th e p ostop erat ive p eriod to obser ve for seizu re act ivit y or eviden ce of in t racran ial bleeding or any oth er n eurologic com p licat ion s. It is also au th ors’ pract ice to give th ree doses of p rop hylact ic an t ibiot ics in th e im m ediate postop erat ive p eriod .
Medication • Antiepileptic prophylaxis of choice (phenytoin or levetiracetam ) is m aintained for a total of 7 days.
Radiographic Imaging • Postoperat ive im aging (Fig. 3.18).
Further Management • Skin su t u res or staples are rem oved after 2 w eeks.
a
b Fig. 3.18a, b Axial CT images after evacuation of (a) frontal and (b) temporal lobe contusions. In each case, an external ventricular drain has been placed to facilitate monitoring of intracranial pressure and therapeutic drainage of cerebrospinal uid.
51
I Cerebral Traum a and Stroke
References 1. Bullock MR, Chesnut R, Ghajar J, et al. Surgical m anagem ent of traum atic parenchym al lesions. Neurosurger y 2006;58(3): S25–46 2. Singou n as EG. Severe h ead inju r y in a p aediat ric pop u lat ion . J Neu rosu rg Sci 1992;36:201–206 3. Gallbraith S, Teasdale G. Pred ict ing th e n eed for op erat ion in th e pat ien t w ith an occult t raum at ic in t racran ial h em atom a. J Neurosurg 1981;55:75–81 4. Gen n arelli T, Spielm an GM, Lang t t T, et al. In u en ce of th e t yp e of in t racran ial lesion on outcom e from severe h ead inju r y. J Neurosurg 982;56:26–32 5. Jallo J, Narayan RK. Gen eral prin cip les of cran iocerebral t rau m a an d t raum at ic hem atom as. In : Sekhar LN, Fessler RG, eds. Atlas of Neurosurgical Tech n iques. New York: Th iem e; 2006: 895–905
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6. Lobato R, Cord obes F, Rivas J, et al. Ou tcom e from severe h ead injur y related to th e t ype of in t racran ial lesion. A com puterized tom ography st udy. J Neurosurg 1983;59:762–774 7. Mandera M, Zralek C, Krawczyk I, Zycinski A, Wencel T, Bazowski P. Surgery or conservative treatm ent in children w ith traum atic intracerebral haem atom a. Child’s Nervous System 1999;15(5):267–269 8. Miller JD, Bu t ter w or th JF, Gu dem an SK, et al. Fu r th er experien ce in th e m anagem en t of severe h ead inju r y. J Neurosurg 1981;54:289–299 9. Nordst rom C, Messeter K, Su n dbarg G, Wah lan der S Severe t rau m at ic brain lesion s in Sw eden. Par t I: Aspect s of m anagem en t in n on -n eu rosurgical clin ics. Brain Inj 1989;3:247–265 10. Solon iu k D, Pit t s LH, Lovely M, Bar tkow ski H. Trau m at ic in t racerebral hem atom as: Tim ing of appearan ce and in dicat ion s for operat ive rem oval. J Traum a 1986;26:787–794 11. Sujit S. Prabh u , Zau n er A, Bu llock MRR. In t racerebral h em atom a an d cerebral con t u sion . In : Win n HR, ed . You m an s Neu rological Surger y. Ph iladelph ia: Elsevier; 2010:5159–5162
4
Decompressive Craniectomy for Intracranial Hypertension and Stroke, Including Bone Flap Storage in Abdominal Fat Layer Roberto Rey-Dios and Dom enic P. Esposito
Introduction The use of a decom pressive craniectom y to treat the sym ptom s of intracranial hypertension w as rst proposed in the late 19th cen tur y by Sir Victor Horsley.1 Koch er popularized its use in Europe. Cushing introduced it in the United States in the early 20th cent ur y as a palliative treatm ent for m ultiple conditions causing intracranial hypertension, including tum ors, hydrocephalus, an d traum a.2 Th e operation fell in to disfavor as advances in neurosurgery during the rst half of the 20th century transform ed m ost of the original indications for decom pressive craniectom y into treatable conditions. In the 1970s, advances in life support increased the sur vival of patients w ith severe head injuries. This operation was revisited w ith the goal of treating traum atic brain injury patients w ith intracranial hypertension not responsive to “m edical treatm ent.”3,4 A collection of good results over th e past t wo decades 5–7 h as turn ed decom pressive craniectom y surgery into an accepted option for the m anagem ent of severe traum atic brain injury w ith refractory intracranial hypertension; new indications are being explored. Several st udies have dem onstrated a decrease in m ortalit y and im proved outcom es w hen this operation is perform ed in the correct patient population.8–10
Indications • Th ere is accum ulated eviden ce to suppor t th e use of decom -
•
pressive cran iectom y for th e follow ing path ologies: ◦ Traum atic brain injury w ith di use or localized cerebral edem a or m ultiple cont usions refractor y to m edical th erapy.10 ◦ Large cerebral in farct ion s resu lt ing in severe edem a an d m ass e ect .11,12 ◦ Som e st u dies h ave sh ow n p rom ising resu lts u sing decom pressive cran iectom y for oth er path ologies presen t ing w ith di use cerebral edem a like an eur ysm al su barach n oid h em orrh age,13 ven ou s th rom bosis,14 or in fect ious en ceph alit is,15 but th e available eviden ce is n ot st rong en ough to allow for a st an dard in dicat ion . Tw o p r im ar y t yp es of d ecom p ressive cran ie ctom ies are p er for m e d : ◦ Fron totem poropariet al (occipit al) decom pressive h em icran iectom y. Th is proced ure is in dicated for t raum at ic lesion s
•
or edem a con cen t rated in on e h em isph ere w ith m idlin e sh ift an d risk of u n cal h ern iat ion . Th is t ype of cran iectom y m ay also be p erform ed in th e set t ing of an isch em ic cerebrovascular even t involving a un ilateral, large vascular territor y (u su ally m id dle cerebral arter y [MCA] or in tern al carot id ar ter y [ICA]) ◦ Bifron tal decom p ressive cran iectom y. Th is p rocedu re is in dicated in cases of di u se, bilateral cerebral edem a or in th e set t ing bilateral fron tal lesion s w ith associated severe ed em a. Decom p ressive cran iectom y m ay be p erform ed early or late 16 : ◦ Early decom pressive cran iectom y is perform ed soon after th e pat ien t arrives to th e em ergen cy depart m en t . Early cran iectom y sh ould be con sidered in pat ien t s w ith m ore th an 5 m m of m idlin e sh ift or if the m idlin e sh ift is out of propor t ion to th e size of th e ext ra-axial m ass lesion (usu ally h em atom a) to be evacu ated.10 ◦ Late decom pressive cran iectom y is u su ally p erform ed w ith in 48 h ou rs of th e origin al in sult , in th e set t ing of m ed ically refractor y elevated in t racran ial pressu re (ICP; de n ed as ICP . 30 m m Hg for greater th an 20 m in utes by protocol at th e auth ors’ m edical cen ter). Late decom pressive cran iectom y sh ou ld on ly be con sidered after failu re of prim ar y t ier th erapy for in t racran ial hyper ten sion . ◦ “Later” decom pressive cran iectom y—longer th an 48 h ou rs after th e in it ial in su lt—m ay be in dicated for pat ien t s w h o develop m align an t edem a follow ing isch em ic st roke, delayed expan sion of con t u sion s, or delayed m align an t cerebral edem a an d/or hyperem ic brain syn drom e.
Preprocedure Considerations Radiographic Imaging • Com pu ted tom ography (CT) is th e m ost com m on im aging m odalit y u sed to evalu ate poten t ial can didates for a decom pressive cran iectom y. CT im ages n ot on ly dem on st rate acu te in t racran ial path ology bu t also provide in form at ion con cern ing bony an atom ic lan dm arks—useful for surgical p lan n ing— an d allow for iden t i cat ion of sku ll fract u res th at m igh t com plicate th e operat ion .
53
I Cerebral Traum a and Stroke
b
a Fig. 4.1a, b Axial CT images for t wo patients—(a) one with traum atic brain injury and (b) one with a large right MCA stroke—selected for decompressive craniectomy.
• CT angiograp hy can be u sefu l to diagn ose m ajor vascu lar oc•
•
clusion s an d vascular injuries associated w ith h ead injuries, part icularly w h en skull base fract ures are presen t . Magn et ic reson an ce im agin g (MRI) is u se d m ore sp ar in gly in t h e con t ext of t rau m a d u e t o t h e ad d e d d ifficu lt y of organ izin g t h e logist ics for life su p p or t in t h e MRI su it e an d t h e lon g d u rat ion of t h e st u d y, w h ich a cr it ically ill p at ie n t m ay n ot t ole rat e. MR d iffu sion -w e igh t e d im ages are u sefu l for early d et e ct ion of large isch e m ic st rokes. Early involve m e n t of t h e n e u rosu rge on in su ch cases is esse n t ial in t h e eve n t t h at lat e r n e u rologic d et e r iorat ion m igh t p rovid e an in d icat ion for e m e rge n t d e com p ressive cra n ie ctom y. Preo perative im aging (Fig. 4.1).
Operative Field Preparation • Th e h air is clipped w ith an elect ric razor. Any foreign bodies • • •
Medication • If the patien t is sh ow ing sign s of im m inent neurologic deterio-
•
54
ration (dilated nonreactive pupil, hem iparesis, decerebrate or decorticate post uring), a bolus dose of m annitol (0.5 to 1 g/kg) can be adm inistered as a tem porizing m easure en route to the operating room . Periop erat ive an t im icrobial p rophylaxis sh ou ld be adm in istered w ith in 1 h ou r of skin in cision . Th e auth ors prefer cefazolin . In th e set t ing of an open skull fract u re an d/or pen et rat ing brain inju r y, t riple an t ibiot ic coverage (gram posit ive, gram -n egat ive, an d an aerobic organ ism s) is in it iated.
•
m ay be rem oved from th e scalp at th is t im e. Hexach lorop h en e (or sim ilar) soap is u sed to clean se th e skin , an d th en 70% alcoh ol is ap plied. Th e skin in cision s are m arked, an d povidon e iodin e or ch lorh exidin e m ay be applied as a n al prep. Th e surgeon also n eeds to m ake a decision at th is t im e about h ow th e bon e ap w ill be preser ved for fu t u re sku ll recon st ru ct ion . Th ere is n ot en ough eviden ce in th e literat u re to su p p or t th e preferen t ial u se of su bcu t an eou s or cr yop reservat ion .17,18 In m ost in st it ut ion s, sterile deep -freezing storage (2 80°C) is available. If storage is n ot available, or if th e p at ien t is ant icipated to con t in ue t reat m en t at a di eren t in st it u t ion before th e an t icip ated t im e of recon st ru ct ion , th e su rgeon sh ou ld p roceed to prep th e abdom en for su bcu t an eous storage. We prefer to store th e bon e ap in th e righ t low er quadran t of th e abdom en . Many pat ien t s w h o sust ain a t raum at ic brain inju r y w ill even t u ally n eed a gast rostom y t u be, so th e left side sh ou ld be avoided. Th e righ t u p per qu adran t sh ou ld be reser ved in th e even t th at th e pat ien t m igh t requ ire a ven t ricu lop eriton eal (VP) sh u n t in th e fu t u re. Consideration should be given to perioperative placem ent of an invasive pressure m onitor, contralateral to the planned surgical site. W hen feasible, placem ent of an external ventricular drain (EVD) is preferred. An EVD w ill perm it both continuous assessm ent of ICP to guide therapy and therapeutic drainage of cerebrospinal uid (CSF) for treatm ent of intracranial hypertension.
4
Decom pressive Craniectom y for Intracranial Hypertension and Stroke
Operative Procedure Decompressive Hemicraniectomy (Frontotemporoparietal [Occipital] Craniectomy) Positioning (Fig. 4.2)
Figure
Procedural Steps
Pearls
Fig. 4.2
The patient is positioned supine on the operating table. The head is secured w ith a three-point head holder and turned a minimum of 60 degrees (ideally 90 degrees) to the opposite side of the planned operation. Depending on the body habitus and exibility of the neck, a roll under the ipsilateral shoulder may be needed to achieve the proper position. Ideally, the parietal eminence should be near parallel to the oor to avoid posterior sagging of the brain after the dural opening.
• The frontal pin is placed on the midpupillary line contralateral
•
to the side of the planned craniectomy. The t wo posterior pins should straddle the m idline, above the transverse sinus. The posterior pins should not be placed laterally, toward the side of the craniectomy, to prevent comprom ising the posterior extent of the craniectomy. If an ICP monitor has not been placed already, now is the tim e to do so. Usually, an entry point contralateral to the craniectomy is chosen. The catheter or wire should be tunneled away from m idline to avoid interference with the incision.
55
I Cerebral Traum a and Stroke
Skin Incision (Fig. 4.3)
Figure
Procedural Steps
Pearls
Fig. 4.3
For a standard hemicraniectomy, the incision w ill start at the level of the zygomatic arch, 1 cm in front the tragus, and extend superiorly and posteriorly in a reverse question mark fashion. The incision w ill end anteriorly at the hairline, close to midline.
• In m any patients, the super cial temporal artery (STA) can be
The skin opening technique varies w ith surgeon preference. The most expedient method that still minimizes blood loss should be used, since trauma patients often have already su ered severe hemorrhage and may be acutely anemic and hypovolemic. The authors prefer to open the skin w ith a no. 10 blade and to advance through the subcutaneous tissue w ith the monopolar. Focal bleeding points are controlled w ith both monoand bipolar electrocautery. Scalp clips are applied immediately to the skin edges to assist hemostasis.
56
•
•
palpated, and the incision designed to avoid it. Maintaining a patent STA will increase the viabilit y of the ap. The posterior portion of the question m ark should be kept uniform in width with the frontotemporal base of the ap to avoid a narrow, poorly vascularized distal end of the ap. This is achieved by allowing the reverse question mark to turn superiorly all the way to m idline rather than directing it inferiorly into the territory m ainly supplied by the occipital artery. A narrow or too caudally directed distal portion of the ap can result in tenuous perfusion, poor wound healing, or frank skin necrosis. In cases of traum a, the ap should extend as posteriorly as possible to include the parietal em inence. In cases of ischem ic stroke, the decompression area should be tailored to the m argins of the infarcted area, allowing only the devitalized brain to bulge through the defect. Once the whole incision is open and hemostasis has been achieved, the m onopolar is used to cut the pericranium along the incision line. The temporalis m uscle and fascia are also cut following the incision line.
4
Decom pressive Craniectom y for Intracranial Hypertension and Stroke
Subcutaneous Dissection (Fig. 4.4)
Figure
Procedural Steps
Pearls
Fig. 4.4
The pericranium is carefully separated from the skull using a Langenbeck type (square) periosteal elevator. A Hoen type (round) periosteal elevator is used to dissect the temporalis muscle. At the superior temporal line, the monopolar is often needed to dissect the more tenacious muscle insertion.
• The pericranium m ust be dissected carefully, without creating
The resultant myocutaneous ap is re ected anteriorly to expose the bone. Retraction can be applied by using Fisch hooks or mini-tow el clamps.
•
tears, since it will be used for the expansive duraplast y. The temporalis m uscle m ust be dissected caudally until the root of the zygom a can be easily palpated to allow for access to the m iddle fossa. A rolled lap sponge m ust be placed at the base of the ap, before applying retraction, to prevent kinking of the arterial supply and hypoperfusion of the ap during the procedure.
57
I Cerebral Traum a and Stroke
Bur Hole Placement (Fig. 4.5)
Figure
Procedural Steps
Pearls
Fig. 4.5
Bur holes are placed in the follow ing locations: 1. Key hole. 2. Above the mastoid posteriorly, high enough to avoid air cells. 3. As low as possible on the squamous portion of the temporal bone, just above the root of zygoma. 4. Tw o or three bur holes spanning the frontoparietal high convexity, about 2 cm lateral to midline to avoid bleeding from veins draining into the sagittal sinus.
• Ideally, the craniectomy should extend 12 to
A no. 3 Pen eld is used to strip the dural attachments from the undersurface of the calvarium at each bur hole site (and betw een holes, w here feasible). The craniotomy is performed using a craniotome. At the level of the sphenoid w ing, a small bur can be used to thin the bone betw een the craniotome cuts above and below the ridge.
58
15 cm in the anteroposterior dimension and from the oor of middle fossa to 2 to 3 cm from midline to avoid injury to the sagit tal sinus. There is evidence to suggest that smaller craniectomy defects are associated with worse outcomes.19 A measuring tape should be used to con rm the measurem ents before placing the bur holes.
4
Decom pressive Craniectom y for Intracranial Hypertension and Stroke
Elevation of the Bone Flap (Fig. 4.6)
Figure
Procedural Steps
Pearls
Fig. 4.6
A periosteal elevator or similar tool is introduced along the posterior edge of the craniotomy and used to elevate the bone ap aw ay from the underlying dura. Remaining dural attachments are severed and gentle leverage applied until the corner of the sphenoid w ing fractures easily. The explanted bone ap is rinsed w ith a saline and bacitracin solution. If freezing is planned, the bone ap can be handed o at this time. If abdominal storage is planned, the ap is kept in antibiotic solution until the time of implantation.
• The sphenoid ridge should fracture with
•
m inim al force. If resistance is encountered, the bone should be thinned further with a bur. Excessive leverage m ay cause a fracture through the sphenoid wing with m edial extension and the potential for severe complications. Elevation of the bone ap alone should produce a dem onstrable drop in ICP.
59
I Cerebral Traum a and Stroke
Re nement of the Temporal Craniectomy (Fig. 4.7)
60
Figure
Procedural Steps
Pearls
Fig. 4.7
Once the bone ap is removed and hemostasis is achieved, the remainder of the squamous portion of the temporal bone must be removed to allow for a subtemporal decompression. This portion of the craniectomy can be performed w ith a Leksell rongeur or w ith the drill, depending on the surgeon’s preference.
• The squam ous portion of the temporal bone must be rem oved until ush with the oor of m iddle fossa. If mastoid air cells are exposed, bone wax should be applied until completely sealed.
4
Decom pressive Craniectom y for Intracranial Hypertension and Stroke
Dural Opening (Fig. 4.8)
Figure
Procedural Steps
Pearls
Fig. 4.8
The dura can be opened in several di erent patterns. The most common is in a U-shape, w ith the base attached to the temporal edge of the craniotomy defect. Other patterns include a medially based ap or stellate opening.
• This is the key portion of the operation. • When opening the dura, it is important to leave a generous cu from the bony edge to facilitate the closure.
61
I Cerebral Traum a and Stroke
Duraplasty (Fig. 4.9)
62
Figure
Procedural Steps
Pearls
Fig. 4.9
Once the dura is open, the surface of the brain is inspected for subdural hematoma. If present, it should be evacuated. The duraplasty can be performed w ith autogenous materials (e.g., pericranium) or synthetic, suturable implants. Pericranium can be harvested easily from its galeal attachment by sharp dissection w ith Metzenbaum scissors. If the pericranium is damaged or contaminated (e.g., open skull fractures, scalp avulsions, etc.), an arti cial implant should be considered.
• If the ICP is high, the dura should be opened
•
slowly, 1 or 2 inches at a tim e. While the brain is decompressing, the pericranial graft can be sutured in placed as the opening is slowly being m ade. In the authors’ experience, a watertight duraplast y, using an autologous pericranial graft, produces the best results. We use 4-0 braided nylon suture in a running fashion for this purpose. The expansive duraplast y should be m ade as generous as possible.
4
Decom pressive Craniectom y for Intracranial Hypertension and Stroke
Bone Flap Storage (Fig. 4.10a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 4.10
(a) A linear incision is performed in the previously designated area of the right low er quadrant. The monopolar is used to create a pocket of adequate size w ithin Camper’s fascia. Good hemostasis must be achieved to prevent formation of hematomas. (b) The bone ap is introduced— convex side out—into the subcutaneous pocket. The skin should be closed in at least tw o layers, according to the surgeon’s preferences.
• This part of the operation can be perform ed by •
an assistant surgeon during the cranial closure or imm ediately after the closure is completed. The subcutaneous pocket should be of su cient size that there is not tension on the skin edges when reapproximation is at tempted. In a particularly sm all and/or skinny patient, it m ay be necessary to split the bone ap in half and “stack” the pieces in the pocket.
63
I Cerebral Traum a and Stroke
Bifrontal Decompressive Craniectomy Positioning (Fig. 4.11)
64
Figure
Procedural Steps
Fig. 4.11
The patient is positioned supine on the operating table. The head is secured w ith a three -point head holder, in a slightly exed position. The pins are placed on the equator of the skull, in a slightly posterior position in order to allow for access to middle fossa.
4
Decom pressive Craniectom y for Intracranial Hypertension and Stroke
Incision Planning (Fig. 4.12)
Figure
Procedural Steps
Pearls
Fig. 4.12
A large, bicoronal incision is planned, w ith the limbs positioned behind the hairline at approximately the level of the coronal suture, extending bilaterally 1 cm in front of the tragus and inferiorly to the zygoma.
• If the preoperative CT provides evidence of temporal lobe injury or edem a with threatened uncal herniation, a m ore posterior incision (up to 3 to 5 cm posterior to the coronal suture) should be planned to allow for temporal bone exposure and subtemporal decompression.
65
I Cerebral Traum a and Stroke
Subcutaneous Dissection (Fig. 4.13)
66
Figure
Procedural Steps
Pearls
Fig. 4.13
A skin incision is made along the previously marked line and clips applied to the skin edges to assist hemostasis. The incision is carried dow n to the level of pericranium superiorly and temporalis fascia inferiorly. The pericranium is opened w ith monopolar cautery—1 to 2 cm posterior to the scalp incision. The temporalis muscle and fascia, likew ise, are opened in line w ith the scalp incision. A periosteal elevator is used to carefully separate the pericranium and anterior belly of the temporalis muscle from the skull, advancing the myocutaneous ap forw ard.
• The dissection should be carried anteriorly to the level of
•
the supraorbital ridges. Fisch hooks, m ini-towel clamps, or heavy silk sutures can be used to m aintain the ap retraction. Opening the pericranium a few centim eters posterior to the scalp incision gains a few extra centimeters of graft material for later use.
4
Decom pressive Craniectom y for Intracranial Hypertension and Stroke
Craniotomy (Fig. 4.14)
Figure
Procedural Steps
Pearls
Fig. 4.14
Bur holes are placed in the follow ing locations and in this order: 1. Bilateral keyhole 2. Bilateral temporal—in the line of the coronal plane from the sagittal sinus bur holes 3. One or tw o just above the frontal sinus 4. One on either side of the sagittal sinus; these bur holes can be placed 1 to 5 cm behind the coronal suture, depending on the amount of exposure desired
• It is imperative to localize the frontal sinuses on the preoperative
•
CT and, whenever possible, to avoid them at the tim e of surgery. If the patient has an extensive, high-reaching frontal sinus system, intraoperative entry is inevitable. In this case, the surgeon should anticipate the need for cranialization of the sinuses before closure and use appropriate antibiotics to cover potential sinus pathogens. We strongly recomm end perform ing the craniotom e cut bet ween the t wo m idline bur holes only after all the other cuts have been made. The dura bet ween the t wo bur holes is stripped from the undersurface of the calvarium with a no. 3 Pen eld and the cut made promptly. This m aneuver allows for adequate exposure to perm it im m ediate control of any bleeding from the sagit tal sinus.
67
I Cerebral Traum a and Stroke
Dural Opening (Fig. 4.15a–c)
a
b
68
c
Figure
Procedural Steps
Pearls
Fig. 4.15
(a) The dura is opened in a broad, U-shaped fashion w ith the base oriented posteriorly. The initial opening is made anteriorly, on either side of the midline. (b) The anterior portion of the sagittal sinus is ligated using tw o silk sutures and severed betw een the ligatures. (c) The opening is carried laterally and once enough exposure is obtained, the falx should be divided completely. At the temporal corners of the opening, a Y-shape incision can be performed to release tension and allow the dural ap to fall posteriorly.
• The falx m ust be divided in its entiret y in the anterior portion. Failure to do so will result in compression of m idline structures, as the swollen frontal lobes will expand again.
4
Decom pressive Craniectom y for Intracranial Hypertension and Stroke
Duraplasty (Fig. 4.16)
Figure
Procedural Steps
Pearls
Fig. 4.16
The same principles described for the hemicraniectomy apply to the bifrontal craniectomy. Whenever possible, autogenous materials should be used. The pericranium can be easily harvested from the elevated scalp ap and usually cut into tw o pieces to allow coverage of the length of the durotomy. Again, w atertight closure is recommended.
• If the frontal sinuses have been violated, the surgeon m ust proceed to cranialize and obliterate them . This should be done after the duraplast y has been completed, to avoid entry of sinus contents into the CSF spaces. The m ucosa is stripped with a curet te and the posterior wall of the sinus is rem oved using rongeurs. The ostia of the sinuses can be obliterated by using temporalis m uscle or fat. A vascularized pedicle of pericranium (usually there is enough left after harvesting the duraplast y graft) is draped over the cranialized sinuses and sutured to the dural cu .
69
I Cerebral Traum a and Stroke
Closing
Th ere is in su cien t eviden ce to recom m en d a speci c regim en or du rat ion of th erapy.
• Per fect h em ost asis sh ou ld be ach ieved on t h e galeal an d
•
• •
tem p oralis m u scle su r faces to avoid su bgaleal h em atom a accu m u lat ion , w h ich w ou ld d efeat t h e p u r p ose of t h e op erat ion . If act ive bleeding is p resen t at th e in terface bet w een th e du ra an d bon e edge, ep idu ral tack-u p su t u res can be p laced . Th is is m ostly h elp fu l along th e superior fron topariet al edge (adjacen t to th e m idlin e), w h ere ven ous bleeding can som et im es be profu se. A su bgaleal d rain (u su ally a 10-m m Jackson -Prat t [JP]) is left in p lace. Th e scalp is closed in a single layer, using 2-0 vert ical m att ress m on o lam en t sut ures.
Postoperative Management Monitoring • Im m ed iately p ostop, th e blood p ressu re m u st be m on itored
• •
•
closely an d kept w ith in a t igh t range—h igh en ough to guaran tee good cerebral p erfu sion pressu re bu t n ot so h igh as to risk h em orrh age. Placem en t of an invasive pressu re m on itor is st rongly recom m en ded, if n ot already don e, to p erm it accu rate assessm en t of ICP in th e postop period. JP drain ou t pu t sh ou ld be m on itored . Th e drain is u su ally left in p lace for up to 48 h ou rs. CSF in th e drain is n orm al an d act u ally ben e cial—both for ICP con t rol an d to preven t leakage from th e in cision . Focal p oin t s of leakage along th e in cision lin e sh ou ld be addressed prom ptly w ith sut ure rein forcem en t an d, if persisten t , prom pt con sid erat ion of fur th er radiograp h ic invest igat ion . Nu rsing st a m u st be in st ru cted to exercise st rict cran iectom y p recau t ion s, in cluding posit ion ing of th e h ead to preven t any pressu re on th e defect , avoidan ce of t igh t dressings, an d rem oval of any equ ipm en t in th e vicin it y th at could injure th e u np rotected brain .
Medication
Radiographic Imaging • Mobilizat ion of th e pat ien t du ring th e rst 24 h ou rs m u st
•
Further Management • Th e ICP m on itor can be rem oved if th e values h ave been sta• •
•
• Adequ ate sedat ion an d an algesia sh ou ld be p rovided du ring
•
• •
70
th e postoperat ive period, w h ile th e pat ien t rem ain s in t u bated an d at risk for in t racran ial hyp erten sion . Neu rom u scu lar blockade can be in t roduced for pat ien t s w ith h igh er ICP valu es or severe respirator y com plicat ion s. Hyperosm olar th erapy—w ith m an n itol or hyper ton ic salin e— is app ropriate if th e ICP rem ain s h igh after decom pression an d rep eat CT iden t i es n o sp ace-occu pying lesion s am en able to surgical th erapy. Periop erat ive an t im icrobial prop hylaxis is given for 24 h ou rs (or un t il th e JP drain is rem oved). If th e pat ien t p resen ted w ith an op en sku ll fract u re, pen et rat ing brain inju r y, or degloving injur y of the scalp, a lon ger cou rse of t riple an t ibiot ic th erapy sh ou ld be con sidered .
be m in im ized to preven t t raum a to th e exposed brain . Th e au th ors d o n ot perform rou t in e p ostop erat ive im aging for th e rst 48 h ours u n less a ch ange in n eurologic exam or a su stain ed in crease in ICP suggests a com plicat ion th at m igh t be am en able to su rgical in ter ven t ion (e.g., subgaleal h em atom a or blossom ing of con t usion s). If im aging is con sidered n ecessar y, CT is th e m odalit y of ch oice for th e sam e reason s described in th e preoperat ive evaluat ion sect ion . MRI can be usefu l in isch em ic st roke pat ien t s to evaluate for possible exten sion of th e st roke volum e if th e pat ien t’s n eurologic st at us deteriorates fur th er an d th ere is n o CT eviden ce of any of th e com plicat ion s m en t ion ed above. Po sto pe rative im aging (Fig. 4.17).
• •
ble an d th e n eurologic st at us of th e pat ien t is st able. Post t rau m at ic hydrocep h alu s is a w ell-described p h en om en on , an d th e in cid en ce h as been rep or ted to be h igh er in pat ien t s un dergoing decom pressive cran iectom y.20 Du ring th e early postoperat ive period, pat ien ts experien ce a dist urbance in CSF dynam ics th at m ay result in the appearance of extra-axial e usions—m ost often ipsilateral, but som et im es cont ralateral or in terhem ispheric—w ith or w ithout an associated increase in ventricular size. This early presentat ion of “extern al” hydroceph alu s is often ben ign an d ten ds to resolve on ce the bone ap is replaced. Th e integrit y of the w oun d in th ese cases can be protected by tem porar y CSF diversion. In som e patien ts, resolut ion of th e extra-axial e u sion s after cran ioplast y is follow ed by the onset of sym ptom atic hydrocephalus, w ith an associated increase in vent ricular size. This delayed presentat ion can occur w eeks or even m onths after su rger y. Th ese pat ien ts t ypically com e to m edical at ten t ion due to an un ant icipated plateau or regression in th eir neurologic recover y and usually require shunting. Sut ures are usually rem oved 14 days after surgery. Th e incision should be m onitored closely for any leaks, especially in patients know n to have posttraum atic hydrocephalus. If CSF continues to leak despite suture reinforcem ent, hydro cephalus and infection should be ruled out. It is im portant to rem em ber that patients w ith hydrocephalus w ho have an active leak m igh t not h ave ventricular en largem ent in im aging studies. W h en ready for m obilizat ion , pat ien t s sh ould be t ted for a protect ive h elm et to be w orn w h en ou t of bed an d d u ring t ran sport . Th e pat ien t sh ou ld be evaluated for recon st ruct ion of th e cran ial vault approxim ately 4 to 6 w eeks post injur y. Replacem en t of th e bon e ap is addressed in Ch apter 25. Ad dit ion al alloplast ic tech n iques for cran ial recon st ruct ion are discussed in Ch apter 26.
4
Decom pressive Craniectom y for Intracranial Hypertension and Stroke
a
b
Fig. 4.17a, b Axial CT images for t wo patients who underwent decompressive craniectomies for (a) traumatic brain injury and for (b) a large MCA stroke. Note that in the case of the MCA stroke, the craniectomy was tailored to encompass the infarcted area only.
Special Considerations
Intraoperative ultrasound can be useful in this context. Postoperative im aging should be obtained as soon as possible.
• Malignan t cerebral edem a m ay be encountered upon opening
• A severely dam aged scalp an d/or sign i can t soft t issue loss
of the dura. W hen this happens, it m ust be addressed expedien tly to prevent herniation of the brain and shearing against the dural and bone edge. Earlier in this chapter w e explained our technique of slow ly opening the dura as the duraplast y graft is being sut ured in place to allow for gradual expan sion of the brain. If the surgeon instead has opened the dura com pletely and brain herniation occurs, the follow ing m easures should be taken :
m ay p resen t a p ar t icu lar ch allenge in th e set t ing of t rau m a. In su ch sit u at ion s, collaborat ion w ith a p last ics or h ead an d n eck su rgeon is essen t ial. Art i cial graft s often are u sed as a tem p orar y m easu re u n t il t issu es h eal su cien tly an d are clean enough to receive a perm an en t graft , if n eeded. Th e so-called “syn drom e of th e t reph in ed” (or “sin king scalp ap syn drom e”) in clu des a com bin at ion of n eu rologic sym p tom s th at can be directly related to th e presen ce of a cran iectom y defect an d th at even t ually im prove after cran ioplast y. Pat ien t s u su ally becom e sym ptom at ic w h en th ey start to sit u p or am bu late. Most com m on sym ptom s are h eadach e, discom fort in th e region of th e cran ial defect , dizzin ess, seizu res, an d p sych iat ric alterat ion s. Som e p at ien ts w ill exp erien ce m ore severe sym ptom s, in clu d ing orth ostat ic veget at ive dysfu n ct ion an d focal cran ial n er ve or m otor de cit s. Sym ptom s are u su ally t riggered or aggravated by th e u p righ t posit ion . Sym ptom at ic pat ien t s sh ou ld be evaluated for a cran ial vault recon st ruct ion as soon as possible.
1. Positioning: Elevate the head of the bed to im prove venous drainage. Rule out kinking of the endotracheal tube and/ or neck. 2. Ven t ilat ion : Ch eck th e air w ay pressure. Th e an esth esiologist sh ou ld u se th e ven t ilat ion m ode th at ach ieves th e low est air w ay p ressu res possible. 3. PCO2 : Ch eck th e en d-t idal PCO2 . Hyper ven t ilat ion can be p erform ed for a brief p eriod of tim e w ith out det rim en t al e ects, an d it can buy som e t im e. 4. Hyperosm olar th erapy: Man n itol, hyperton ic salin e, an d loop diu ret ics can be u sed. Investigate th e volu m e st at us of th e pat ien t an d elect rolytes. 5. CSF drain age: If a ven t ricular cath eter is in place, m ake su re it is open to drain an d set as low as possible. Con sider t apping th e ven t ricle th rough th e exposed an terior fron tal lobe if a ven t riculostom y w as n ot previou sly in serted. 6. Low ering of CMRO2 : Con sid er a bolu s of barbit u rates or etom idate. 7. Undiagnosed m ass lesion: Bear in m ind that a hem atom a— either extra-axial or intraparenchym al—m ay develop as a result of reperfusion achieved by opening the cranial compartm ent.
•
References 1. Horsley V. Address in Su rger y: Delivered at th e seven t y-fou r th an n ual m eet ing of th e brit ish m edical associat ion . Br Med J 1906;2(2382):411–423 2. Cu sh ing H. Tech n ical m eth ods of p erform ing cer t ain cran ial op erat ion s. Surg Gyn ecol Obstet 1908;3(6):227–246 3. Kjellberg RN, Prieto A Jr. Bifron t al d ecom p ressive cran iotom y for m assive cerebral edem a. J Neurosurg 1971;34(4):488–493
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I Cerebral Traum a and Stroke 4. Ve n es JL, Collin s W F. Bifron t al d e com p ressive cran ie ct om y in t h e m an age m e n t of h ead t rau m a . J Ne u rosu rg 1 9 7 5 ;4 2(4 ): 429–433 5. Gaab MR, Rit t ierodt M, Loren z M, Heissler HE. Trau m at ic brain sw elling an d operat ive decom pression : a prospect ive invest igat ion . Act a Neu roch ir Suppl (Wien ) 1990;51:326–328 6. Aarabi B, Hesdor er DC, Ah n ES, Aresco C, Scalea TM, Eisen berg HM. Ou tcom e follow ing decom p ressive cran iectom y for m align ant sw elling du e to severe h ead injur y. J Neurosurg 2006;104(4):469–479 7. Morgalla MH, Will BE, Roser F, Tat agiba M. Do long-term resu lt s ju st ify decom pressive cran iectom y after severe t raum at ic brain injur y? J Neurosu rg 2008;109:685–690 8. Weiner GM, Lacey MR, Mackenzie L, et al. Decom pressive craniectomy for elevated intracranial pressure and its e ect on the cum ulative ischem ic burden and therapeutic intensity levels after severe traum atic brain injury. Neurosurgery 2010;66(6):1111–1118 9. Eberle BM, Sch n ü riger B, In aba K, Gr u en JP, Dem et riades D, Belzberg H. Decom pressive cran iectom y: su rgical con t rol of t rau m at ic in t racranial hyper ten sion m ay im prove outcom e. Injur y 2010;41(7):934–938 10. Bu llock MR, Ch esn u t R, Gh ajar J, et al. Gu idelin es for th e Su rgical Man agem en t of Traum at ic Brain Inju r y Auth or Group. Neurosurger y 2006;58(3):S2–62 11. Kakar V, Nagaria J, Kirkp at rick JP. Th e cu rren t st at u s of d ecom pressive cran iectom y. Br J Neurosurg 2009;23(2):147–157 12. Vah edi K, Hofm eijer J, Ju et tler E, et al. Early decom pressive su rger y in m align an t in farct ion of th e m iddle cerebral ar ter y: a pooled an alysis of th ree ran dom ised con t rolled t rials. Lan cet Neurol 2007;6(3):215–222
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13. Sch irm er CM, Hoit DA, Malek AM. Decom p ressive h em icran iectom y for th e t reat m en t of in t ract able int racranial hyperten sion after an eur ysm al subarach n oid h em orrh age. St roke 2007;38(3):987–992 14. Ste n i R, Lat ron ico N, Corn ali C, Rasu lo F, Bollat i A. Em ergen t decom pressive cran iectom y in p at ien t s w ith xed dilated p u p ils du e to cerebral ven ou s an d du ral sin u s th rom bosis: rep or t of th ree cases. Neu rosu rger y 1999;45(3):626–629 15. Adam o MA, Desh aies EM. Em ergen cy decom pressive cran iectom y for fulm in at ing infect ious en ceph alit is. J Neu rosurg 2008;108(1):174–176 16. Coloh an AR, Gh ost in e S, Esp osito D. Exploring th e lim it s of su rvivabilit y: rat ion al in dicat ion s for decom p ressive cran iectom y an d resect ion of cerebral con t u sion s in adu lt s. Clin Neu rosu rg 2005;52:19–23 17. Flan n er y T, McCon n ell RS. Cran iop last y: w hy th row th e bon e ap out? Br J Neurosurg 2001;15(6):518–520 18. In am asu J, Ku ram ae T, Nakat su kasa M. Does di eren ce in th e storage m eth od of bon e ap s after d ecom p ressive cran iectom y a ect th e in ciden ce of su rgical site in fect ion after cran iop last y? Com parison bet w een su bcu t an eou s p ocket an d cr yopreser vat ion . J Traum a 2010;68(1):183–187; discussion 187 19. Jiang JY, Xu W, Li W P, et al. E cacy of st an dard t rau m a cran iectom y for refractor y in t racran ial hyper ten sion w ith severe t raum at ic brain injur y: a m ult icenter, prospect ive, ran dom ized cont rolled st udy. J Neurot rau m a 2005;22(6):623–628 20. Ch oi I, Park HK, Ch ang JC, Ch o SJ, Ch oi SK, Byu n BJ. Clin ical factors for th e develop m en t of p ost t rau m at ic hydrocep h alus after decom pressive cran iectom y. J Korean Neurosurg Soc 2008;43(5):227–231
5
Surgery for Cerebellar Stroke and Suboccipital Trauma Faiz U. Ahm ad and Ross Bullock
Introduction Acu te cerebellar p ath ology—in th e form of h em orrh age, sw elling, an d/or in farct ion —rep resen ts on e of th e m ost urgent an d t reach erou s of n eurosurgical em ergen cies. Pat ien ts presen t ing w ith th ese con dit ion s can deteriorate rapidly an d irreversibly. Posterior fossa h em atom as an d in farct s m ay com p ress th e low er brain stem respirator y an d cardiovascu lar cen ters, t riggering respirator y arrest an d cardiac in st abilit y. Em ergen t surgical in ter ven t ion is usually life-saving.1–4 Tim ely in ter ven t ion len ds it self to a bet ter overall progn osis in su ch p at ien t s becau se com a often resu lt s from hydrocep h alu s (u sually reversible) an d brain stem com pression (rath er th an d est ru ct ion ).5–10 Also, th e fact th at th e cerebral h em isph eres rem ain relat ively u n a ected allow s m any of th ese pat ien t s to retain th eir prem orbid person alit ies an d h igh er-order cogn it ive fu n ct ion d esp ite presen t ing in com a before su rger y.
Indications Spontaneous Cerebellar Hemorrhage Several factors m u st be con sidered before deciding to op erate: • Size of h em atom a: Surgical in ter ven t ion gen erally is in dicated for lesion s of greater th an 3 to 4 cm to im prove clin ical con dit ion an d preven t secon dar y deteriorat ion du e to cerebellar sw elling an d h ern iat ion .9,11 • Neu rologic st at u s: Th e p resen ce of sign s an d sym ptom s att ribut able to hydroceph alus (agitat ion , con fusion , leth argy), brain stem com pression (sixth or seven th n er ve palsy, h orizon t al gaze paresis, hem iparesis), or com a sh ould prom pt em ergen t su rgical in ter ven t ion . • Tim e sin ce ict u s: Pat ien t s presen t ing w ith in 6 to 48 h ou rs of h em orrh age often experien ce n eu rologic deteriorat ion due to a com bin at ion of sw elling an d re-h em orrh age. By con t rast , th ose presen t ing 5 to 7 days after th e in it ial bleed t ypically im p rove or rem ain st able. • Issu es t angen t ial to th e p rim ar y path ology: Age, com orbidit ies, social sit u at ion , an d advan ce direct ives also m ust be taken in to accoun t . A n u rsing h om e–con n ed, 80-year-old pat ien t w ith dem en t ia an d m ult iple m edical com orbidit ies, presen t ing in com a, m ay n ot an appropriate can didate for su rgical m an agem en t .11–14
Cerebellar Infarction • Th e in dicat ion s for decom pressive surger y are broadly th e
•
sam e as th ose for h em orrh age. How ever, th e clin ical cou rse ten ds to evolve m ore slow ly.15,16 Resect ion of th e in farcted cerebellum itself is seldom h elpful. Cerebellar h em isph ere in farct ion (due to dist al posterior in ferior cerebellar arter y [PICA] occlusion ) cau sing brain stem com pression sh ould be di eren t iated—by com puted tom ography (CT) an d/or m agn et ic reson an ce im aging (MRI)—from brain stem dest ruct ion due to proxim al isch em ia, as th e lat ter w ill n ot im prove w ith surger y.
Trauma • Pat ien ts p resen t ing w ith posterior fossa epidu ral h em atom a
•
•
(EDH) or acu te subdural h em atom a (SDH) w h o are aw ake an d m eet all of th e follow ing radiograp h ic criteria can be m an aged con ser vat ively, un der close super vision : clot volum e less th an 10 m L, h em atom a th ickn ess less th an 15 m m , an d m idlin e sh ift less th an 5 m m .17 Conversely, pat ien ts w h o presen t w ith a depressed level of con sciousn ess, focal n eurologic de cit s, an d/or om in ou s n dings on CT scan (hydrocep h alu s, obliterated p erim esen cep h alic cistern s, an d/or a disp laced fou rth ven t ricle) are can didates for early surgical in ter ven t ion .1,3,6,18,19 Th e in dicat ion s for operat ive in ter ven t ion in th e set t ing of t raum at ic in t racerebellar h em atom as are sim ilar to th ose for spon t an eou s h em orrh age (see above).
Preprocedure Considerations Radiographic Imaging • Non con t rast CT p rovides ad equ ate in it ial im aging in th e set• •
t ing of t raum a or h em orrh age. MRI—in p art icu lar, di u sion -w eigh ted im aging (DW I)—m ay be a usefu l adjun ct in th e set t ing of st roke to di eren t iate brain stem from cerebellar h em isph ere isch em ia. If th e in it ial CT scan reveals eviden ce of su barach n oid h em orrh age an d/or blood in th e fou r th ven t ricle, preoperat ive vascu lar im aging (angiogram or CT angiogram ) sh ould st rongly be con sidered to ru le out an un derlying an eu r ysm or arterioven ou s m alform at ion . Th e p resen ce of an u n derlying vascu lar lesion m ay dictate a ch ange in operat ive plan an d/or p reop erat ive en dovascu lar in ter ven t ion .
73
I Cerebral Traum a and Stroke • A pat ien t w ith a kn ow n p osterior fossa h em atom a (t rau m at ic
• A st at bolus dose of m an n itol (0.5–1 g/kg in t raven ous pig-
or spon t an eous) w h o is deteriorat ing rapidly sh ould be t aken to th e op erat ing room directly, w ith ou t a rep eat CT scan . Th e t im e requ ired to com plete an addit ion al diagn ost ic st u dy m ay n ot be w or th th e diagn ost ic yield in th is set t ing. Preo perative im aging (Fig. 5.1).
gyback [IVPB]) m ay be given if clin ical deteriorat ion occurs. Oth er w ise, a bolu s is adm in istered prior to skin in cision in th e operat ing room . Th ere is n o role for preoperat ive an t iepilept ics un less th ere is con curren t supraten torial h em orrh age. Prophylact ic an t im icrobial prophylaxis (th e auth ors prefer cefuroxim e) to cover gram -posit ive organ ism s is given per h osp it al p rotocol.
•
• •
Ventriculostomy • Th e propen sit y of posterior fossa m ass lesions to cause
•
•
obst ruct ive hydroceph alu s m ean s th at a presurgical ven t ricu lostom y is alm ost alw ays m an dator y before decom pression . Failure to do so m ay result in m assive hern iat ion of th e posterior fossa con ten t s in to th e decom pression , cau sing death on th e operat ing table. Th e ven t riculostom y sh ould be in serted ver y rap idly to avoid delay in th e deteriorat ing pat ien t , an d m ay be don e as a p ar t of th e decom pression (see below ). Occasion ally, in m oribu n d pat ien t s, or in th ose w ith sm aller posterior fossa h em orrh agic lesion s, a ven t riculostom y m ay be placed, an d th e pat ien t obser ved an d re-scan n ed in 3 to 4 h ours to determ in e if de n it ive su rger y is in dicated (e.g., if clin ical im provem en t or en largem en t of h em atom a occurs). Many au th ors advocate carefu l t it rat ion of th e h eigh t of th e drain (e.g., st art ing at 30 cm w ater an d th en low ering it by 5 cm w ater decrem en t s ever y h our un t il 10 cm w ater is reached) in order to avoid “upw ard t ran sten torial h ern iat ion .” Th is m ay be m ore im por tan t in th e set t ing of n eoplast ic posterior fossa m ass lesion s, w h ere edem a an d a m ore prot racted clin ical cou rse m ake th is com plicat ion m uch m ore com m on .
Positioning and Operative Field Preparation • To m ain t ain adequate h ead
•
•
Medication • Th e use of sedat ive-hypn ot ic agen t s sh ould be avoided. Such m edicat ion s m ay con fou n d th e clin ical exam in at ion an d p recipit ate respirator y depression .
74
•
exion an d rot at ion , a th reepin ion h ead h older is essen t ial. Th e cross bar sh ou ld be padded to preven t pressure injur y w ere slippage of th e pin s to occur (e.g., w h ere th e bridge of th e n ose or foreh ead w ould con t act th at cross bar). For evacu at ion of a p red om in an t ly u n ilateral h em atom a, t h e lateral p ark ben ch p osit ion —w it h t h e h ead t u r n ed to t h e con t ralateral sid e an d exed —is su it able. For su bd u ral or ext rad u ral h em atom as exten d in g bilaterally, an d for u n ilateral cerebellar in farct ion s (w h ere exten sive foram en m agn u m d ecom p ression is n eed ed), t h e p ron e p osit ion is ch osen . For t rau m a cases, w e at tem pt to red u ce/m in im ize cer vical exion d u r in g p osit ion ing if t h e cer vical sp in e h as n ot been cleared . Th e cer vical collar is rep laced after t h e p roced u re. Eith er an iodin e-based prep arat ion or ch lorh exidin e/alcoh olbased solut ion is u sed for skin preparat ion , taking care th at th e solut ion does n ot en ter th e eyes, especially in pron e posit ion . We use a t ran sparen t adh esive dressing lm over th e eyes to protect th e corn ea. Th e in cision is m arked an d in lt rated w ith 1% lidocain e w ith ep in ep h rin e 1:100,000.
5
Surgery for Cerebellar Stroke and Suboccipit al Traum a
a
b
c
d
e
Fig. 5.1a–e Axial CT images demonstrating an (a) epidural hematoma, (b) intracerebellar hematoma, and (c) left cerebellar infarction with m ass e ect on the fourth ventricle. (d) MRI DWI sequence dem onstrating restricted di usion in the region of the infarction depicted in (c). DWI m ay distinguish the cerebellar stroke shown in from one that extends proximally to the adjacent brainstem (e). This distinction is important as the lat ter is unlikely to improve with surgery.
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I Cerebral Traum a and Stroke
Operative Procedure Positioning (Fig. 5.2a, b)
a
b
76
Figure
Procedural Steps
Pearls
Fig. 5.2
Choice of the (a) prone or (b) lateral park bench position is dictated by the location of the clot, anticipated extent of exposure, and urgency of the situation (see above).
• Make sure to protect the eyes, face, and cervical spine (if not cleared). Ensure that an arm ored endotracheal tube is used and secured well (by suture or tape and ties) to the external face and head holder.
5
Surgery for Cerebellar Stroke and Suboccipit al Traum a
Skin Incision (Fig. 5.3)
Figure
Procedural Steps
Pearls
Fig. 5.3
The skin incision is alw ays marked prior to skin preparation to avoid confusion after draping. If positioned prone, a midline incision is planned from the inion to the spinous process of C2. It can be extended later, if needed. A paramedian incision is used for unilateral intraparenchymal hematomas.
• Mark the m idline and the
The entry point for a ventriculostomy (if not placed preoperatively) should be planned and marked, using anatomic landmarks: 5 cm above the inion and 3 cm lateral to midline.
position of transverse sinus (extrapolate from a line connecting the zygom a to the inion) prior to skin incision.
A no. 10 blade is used to incise the skin along the previously marked line. The initial incision is carried dow n to the level of deep dermis.
77
I Cerebral Traum a and Stroke
Subcutaneous Dissection (Fig. 5.4a, b)
a
78
b
Figure
Procedural Steps
Pearls
Fig. 5.4
(a) If using a midline approach, monopolar electrocautery is used to incise the subcutaneous fat and then deepen the incision in the avascular plane of ligamentum nuchae. The fascia should be cut sharply w ith a knife, instead of cautery, to avoid shrinkage. Self-retaining posterior fossa retractors assist retraction of the skin edges at this level. (b) If using a paramedian approach, muscle is divided in line w ith the skin incision, using monopolar electrocautery. The occipital branch of the external carotid artery (betw een the third and fourth layers of posterior cervical muscles) should be identi ed, coagulated w ith bipolar cautery, and divided sharply. Hemostasis is attained w ith monopolar or bipolar electrocautery.
• Monopolar electrocautery should not be used when dissecting the tissue laterally at the level of foram en m agnum and C1. Careful sharp dissection with Met zenbaum scissors (after thinning out the tissue by spreading) is recom mended to avoid injury to the vertebral artery at this level.
5
Surgery for Cerebellar Stroke and Suboccipit al Traum a
Bony Exposure (Fig. 5.5)
Figure
Procedural Steps
Pearls
Fig. 5.5
The bony exposure should extend from the inion to the foramen magnum. A w ide exposure is needed for cerebellar infarcts, extending laterally to a centimeter from the mastoid process. This essentially means incorporating the w hole of the w ide bony exposure into the craniotomy. A smaller exposure (either unilateral or bilateral depending upon the pathology) is needed for hematomas. Additional exposure can be obtained if necessary based on the CT scan ndings.
• Care should be taken to avoid stripping the muscles o the spinous process and lam ina of C2 as this is a m ajor insertion point for m any of the stabilizing m uscles of the neck.
The C1 posterior arch is alw ays exposed (20 mm on each side) but need not be resected. Deep cerebellar retractors spread the skin and dissected muscles at this level.
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I Cerebral Traum a and Stroke
Bur Hole Placement (Fig. 5.6a, b)
a
80
b
Figure
Procedural Steps
Pearls
Fig. 5.6
(a) Bur holes are placed at the level of the transverse sinus (approximately 1 cm below the inion), to either side of midline. We typically use a perforator drill; alternately, a matchstick or acorn bur may be employed. A second set of bur holes can be made at the lateral edge of the craniotomy if the dura is very stuck to the bone, but typically only tw o are required. (b) For a paramedian approach, one bur hole is placed in the midline position and one at the lateral edge of the planned opening.
• Protect the drill from slipping into the foram en m agnum region during initial stages of the drilling.
5
Surgery for Cerebellar Stroke and Suboccipit al Traum a
Craniectomy (Fig. 5.7)
Figure
Procedural Steps
Pearls
Fig. 5.7
An 8-mm acorn bur is used to thin the thick bone buttresses over the transverse sinuses and cerebellar convexities. When a thin shell of bone remains, a combination of Leksell rongeur and Kerrison punches may be used to complete the craniectomy.
• The size of the craniectomy depends on the underlying pathology. Typically, infarction requires a larger exposure than hem atom a.
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I Cerebral Traum a and Stroke
Epidural Hematoma Evacuation (Fig. 5.8)
Figure
Procedural Steps
Pearls
Fig. 5.8
In the case of an epidural hematoma, clot is immediately visible upon bony removal. Hematoma is evacuated by gentle suction. Focal bleeding points along the dural surface are identi ed and coagulated. Gelatin sponge pow der (or bone w ax, if pow der is not e ective) is applied to the bone edges.
• Rapid, partial decompression of the
Clot removal over the sinus may produce heavy bleeding from a sinus tear. Small amounts of clot stuck to the sinuses should be left intact. There is no need to open the dura if the brain appears slack after evacuation of the epidural hematoma. How ever, if the dura is tense, subdural exploration is indicated to look for any additional clots (subdural or intracerebellar hematoma).
82
brain can be achieved by suctioning visible clot through the bur holes, prior to completion of the bony opening. However, care must be taken to avoid suctioning in the direction of the venous sinuses.
5
Surgery for Cerebellar Stroke and Suboccipit al Traum a
Dural Opening and Subdural Hematoma Evacuation (Fig. 5.9)
Figure
Procedural Steps
Pearls
Fig. 5.9
The dura is opened in a Y-shaped fashion to gain adequate access to the posterior fossa contents. The superior limbs of the Y should commence just inferior to the transverse sinus. Either clot or cerebellum w ill usually bulge out from the dural opening at this stage. Complete the dural opening expediently w hile protecting the brain w ith a piece of nonadherent bandage or a cotton pattie to avoid incarceration betw een the dural edges. The inferior aspect of the opening (the stem of the Y) should extend to the foramen magnum. The dural edges may be held open w ith 4-0 braided nylon sutures.
• The ventriculostomy should be opened to drain at a • •
height of 10 to 15 cm water (zeroed to ear level) at this stage. Be prepared for tears of the transverse sinus in trauma cases (ligating clip system , pressure, head up position). A persistent circular sinus (or venous lakes within the dural leaves) can be a problem in children and occasionally m ay be encountered in adults. Coagulation with bipolar electrocautery and/or the use of ligating vascular clips m ay be necessary.
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I Cerebral Traum a and Stroke
Intracerebellar Hematoma Evacuation (Fig. 5.10)
84
Figure
Procedural Steps
Pearls
Fig. 5.10
In case of an intracerebellar hematoma, a 2- to 3-cm corticectomy is made over the site of clot presentation w ith a bipolar and microscissors/ no. 11 blade. White matter is gently suctioned in the direction of the clot until the hematoma cavity is accessed. A brain cannula (e.g., Dandy) can be passed into the clot to assist in localization.
• Ultrasound can be useful for sm aller
The clot is gently suctioned out using no. 9 or no. 12 suction tips. Discrete bleeding points are identi ed and coagulated. Self-retaining brain retractors assist the exposure during hemostasis. Fukushima (teardrop side port) suction tips (e.g., no. 7) may be useful during the hemostasis stage.
• Surgical loupes and a headlight are
The brain w ill usually be slack after clot removal. If not, cerebrospinal uid drainage from the cisterna magna should be attempted prior to resection of edematous cerebellum.
• Always keep in m ind the location of
and/or deeply located hem atom as, or if the hem atom a is not found at the anticipated site after the corticectomy.
useful adjuncts at this point.
the fourth ventricle while suctioning the depths of the hem atom a cavit y.
5
Surgery for Cerebellar Stroke and Suboccipit al Traum a
Decompression of Infarcted Brain (Fig. 5.11)
Figure
Procedural Steps
Pearls
Fig. 5.11
In the case of surgery for infarction, w ide decompression is the primary objective. The posterior rim of the foramen magnum should alw ays be opened. Resection of infarcted cerebellum is required only if closure is di cult. Release of cerebrospinal uid from the cisterna magna is more useful for infarcts than for hematoma.
• In som e cases, severe cerebellar swelling due to autonom ic dysregulation can occur.
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I Cerebral Traum a and Stroke
Hemostasis (Fig. 5.12)
86
Figure
Procedural Steps
Fig. 5.12
Hemostasis is attained w ithin the resection cavity w ith pinpoint bipolar coagulation and again con rmed by Valsalva maneuver. The w alls of the cavity then are lined w ith an absorbable hemostatic agent.
5
Surgery for Cerebellar Stroke and Suboccipit al Traum a
Dural Closure (Fig. 5.13)
Figure
Procedural Steps
Pearls
Fig. 5.13
Once an adequate decompression is achieved, the native dura is not reapproximated. Duraplasty may be performed w ith local pericranium, cadaveric dura, or synthetic materials. Dural substitutes may be used as an onlay or incorporated w ith the native dural edges using a 4-0 braided nylon suture.
• Duraplast y, in the set ting of cerebellar
Epidural tacking stitches are not necessary except in the setting of epidural hematoma.
• If epidural tacking stitches are placed, care
infarction, is m andatory to accom m odate anticipated swelling.
must be taken (in particular, along the superior edge) to avoid the venous sinuses.
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I Cerebral Traum a and Stroke
Closing
of use. Altern ately, 3-0 nylon or polypropylen e in terrupted st itch es m ay be u sed for skin closu re.
• Th e cran iectom y defect is n ot closed. Replacem en t of bon e
• • • • •
or m esh recon st ruct ion of th e calvarium w ould defeat th e purpose of th e procedure. Pat ien ts seldom require delayed cran ioplast y for th is in dicat ion . After ach ieving h em ostasis an d irrigat ing th e w ou n d w ith an t ibiot ic solu t ion , th e n eck m u scles are ap proxim ated loosely w ith 2-0 braided absorbable in terru pted sut u res. The need for a subgaleal drain is assessed on a case-by-case basis. Th e fascia is closed t igh tly w ith th e sam e sut ure. Su bcu t an eou s t issu es are ap p roxim ated w ith 3-0 braided ab sorbable su t u res. Th e auth ors prefer to approxim ate th e skin w ith st aples due to th eir in er t n ess, m in im al risk for t issu e n ecrosis, an d sp eed
Postoperative Management Ventriculostomy • Ven t ricu lostom y is m an dator y to p reem pt recu rren ce of •
obst ruct ive hydroceph alus (secon dar y to h em orrh age or sw elling) in th e early postoperat ive period . Th e drain is m ain tain ed in th e open posit ion , at a h eigh t of 10 cm H2 O. If drain age is m in im al (, 50 m L) in 24 h ou rs, it is closed for 24 h ou rs an d th en rem oved, provided a repeat CT scan sh ow s n orm al ven t ricu lar size.
a
b
c
d Fig. 5.14a–d (a) Axial CT image demonstrating resolution of hydrocephalus following evacuation of a posterior fossa epidural hem atoma. (b) Axial CT soft tissue and (c) bone windows dem onstrating a tailored approach for evacuation of an intracerebellar hematoma. (d) Axial CT bone window demonstrating the bony margins of a wide suboccipital craniectomy for decompression in the set ting of ischemic stroke.
88
5
Monitoring • Th e pat ien t is obser ved in a m on itored set t ing (in ten sive care •
u n it), at least overn igh t . No sedat ion is given if th e p at ien t is ext u bated.
Medication • Prophylact ic an t ibiot ics are con t in ued for 24 h ours, regardless of th e p resen ce of ven t ricu lostom y.
Radiographic Imaging • A n on con t rast CT scan is obt ain ed in th e early postopera-
•
t ive period to assess th e st at us of th e h em orrh age, decom p ression , an d ven t ricular size. Th e early postoperat ive st udy also allow s screen ing for th e develop m en t of a delayed epidural or in t racerebral h em orrh age at a dist an t , supraten torial locat ion —w h ich is n ot un com m on . Po sto perative im aging (Fig 5.14).
Further Management • Th e drain (if presen t) is rem oved over th e n ext 24 to 48 h ours. • Skin su t u res or st aples are rem oved after 1 to 2 w eeks.
References 1. Hayash i T, Kam eyam a M, Im aizu m i S, Kam ii H, On u m a T. Acu te epidural h em atom a of the posterior fossa—cases of acute clin ical deteriorat ion . Am J Em erg Med 2007;25:989–995 2. Elliot t J, Sm it h M. Th e acu t e m an age m e n t of in t race reb ral h e m or rh age: a clin ical review . An est h An alg 2010;110:1419– 1427 3. Karasu A, Saban ci PA, Izgi N, Im er M, Sen cer A, Can sever T, Can bolat A. Trau m at ic epid u ral h em atom as of th e p osterior cran ial fossa. Surg Neurol 2008;69:247–251 4. Koc RK, Pasaoglu A, Men ku A, Oktem S, Meral M. Ext radu ral h em atom a of th e posterior cran ial fossa. Neu rosurg Rev 1998;21:52–57
Surgery for Cerebellar Stroke and Suboccipit al Traum a 5. Ciu rea AV, Nu tean u L, Sim ion escu N, Georgescu S. Posterior fossa ext radu ral h em atom as in ch ild ren : rep or t of n in e cases. Ch ilds Ner v Sys 1993;9:224–228 6. Berker M, Cat altepe O, Ozcan OE. Trau m at ic epid u ral h aem atom a of th e posterior fossa in ch ildh ood: 16 n ew cases an d a review of th e literat u re. Br J Neu rsu rg 2003;17:226–229 7. Bozbuga M, Izgi N, Polat G, Gu rel I. Posterior fossa ep idu ral h em atom as: obser vat ion s on a series of 73 cases. Neurosu rg Rev 1999;22:34–40 8. Moh an t y A, Kollu ri VR, Su bbakrish n a DK, Sat ish S, Mou li BA, Das BS. Prognosis of ext radural h aem atom as in ch ildren . Pediat r Neurosurg 1995;23:57–63 9. Don au er E, Loew F, Fau ber t C, Alesch F, Sch aan M. Progn ost ic factors in th e t reat m en t of cerebellar h aem orrh age. Act a Neuroch ir (Wien ) 1994;131:59–66 10. Mah ajan RK, Sh arm a BS, Kh osla VK, Tew ari MK, Math uriya SN, Path ak A, Kak VK. Posterior fossa ext radural h aem atom a— experien ce of n in eteen cases. An n Acad Med Singap ore 1993;22:410–413 11. Auer LM, Auer T, Sayam a I. In dicat ion s for surgical t reat m en t of cerebellar h aem orrh age and in farct ion . Act a Neuroch ir (Wien ) 1986;79:74–79 12. Ogungbo BI. Posterior fossa decom pression an d clot evacuat ion for fou r th ven t ricle h em orrh age after an eu r ysm al ru pt u re: case report . Neurosurger y 2002;50:1166–1167 13. Kirollos RW, Tyagi AK, Ross SA, van Hille PT, Marks PV. Man agem en t of spon t an eous cerebellar h em atom as: a prospect ive t reatm en t protocol. Neurosurger y 2001;49:1378–1386 14. Math ew P, Teasdale G, Ban n an A, Oluoch - Olunya D. Neurosu rgical m an agem en t of cerebellar h aem atom a an d in farct . J Neurol Neurosurg Psych iat r y 1995;59:287–292 15. Tan eda M, Ozaki K, Wakayam a A, Yagi K, Kan eda H, Irin o T. Cerebellar in farct ion w ith obst r uct ive hydroceph alus. J Neurosurg 1982;57:83–91 16. Kh an M, Polyzoidis KS, Adegbite AB, McQueen JD. Massive cerebellar infarct ion : “con ser vat ive” m an agem en t . St roke 1983; 14:745–751 17. Wong CW. Th e CT criteria for con ser vat ive t reat m en t—bu t un der close clin ical obser vat ion —of posterior fossa epidural h aem atom as. Act a Neurochir (Wien ) 1994;126:124–127 18. Bor-Seng-Sh u E, Aguiar PH, de Alm eida Lem e RJ, Man del M, An drade AF, Marin o R, Jr. Epidural h em atom as of th e posterior cran ial fossa. Neu rosurg Focus 2004;16:ECP1 19. d’Avella D, Ser vadei F, Scerrat i M, et al. Trau m at ic in t racerebellar h em orrh age: clin icoradiological an alysis of 81 pat ien t s. Neurosurger y 2002;50:16–25
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6
Elevation of Depressed Skull Fractures Anand Veeravagu, Bow en Jiang, and Odet te A. Harris
Introduction
Preprocedure Considerations
Depressed cran ial sku ll fract u res often resu lt from h igh en ergy, blun t , t rau m at ic im pact s. Most depressed fract ures are located in th e fron topariet al region . Alth ough clin ical p resen tat ion is variable, ap p roxim ately 25% of p at ien ts w ith dep ressed fract ures presen t w ith loss of con sciousn ess an d clin ical sequelae of in t racran ial h em orrh age.1 A depressed cran ial fract ure m ay be ch aracterized fu rth er as “open ” or “closed,” based on th e in tegrit y of th e overlying scalp . Closed fract u res, w h erein th e scalp is in tact , m ay be t reated n on su rgically if th e depth of th e dep ressed segm en t is less th an th e m easu red w idth of th e calvarial bon e adjacen t to th e fract ure. Open fract ures com m un icate w ith th e extern al environ m en t an d, as su ch , are presu m ed con tam in ated. Su rgical in terven t ion is often requ ired in th ese cases for debridem en t , rep air of dural lacerat ion s, clean sing of bon e fragm en ts, evacu at ion of u n derlying h em atom a, an d elevat ion of th e depressed fract u re.
Radiographic Imaging • Com puted tom ography (CT) is th e st an dard im aging m odalit y
• • •
u sed to assess calvarial in tegrit y an d associated in t racran ial injur y in th e acu te set t ing. CT ven ogram (CTV) m ay be u t ilized to assess sin u s inju r y. Magn et ic reson an ce im aging (MRI)/angiograp hy (MRA) m ay be used to diagn ose suspected vascular injur y (e.g., to a dural ven ou s sin u s). An teroposterior an d lateral skull radiograph s are used rarely to delin eate bony injur y an d/or th e presen ce of m issile fragm en t s. Preo perative im aging (Fig. 6.1).
Medication • Op en fract u res sh ou ld be t reated con sisten t w ith oth er op en
Indications
2
• Prese n ce of an op en , d ep ressed fract u re in an in fan t or • • •
•
90
ch ild . Dep ression of t h e fract u re segm en t greater t h an 5 m m below t h e in n er t able of t h e adjacen t calvar ial bon e in an ad u lt . Presence of gross contam ination, signi cant ext ra- or int raaxial h em atom a, an d/or pn eum oceph alus suggest ive of a dural tear. Neu rologic p rogression in th e set t ing of a closed fract u re m ay be due to an associated expan ding h em atom a or com pressive e ect of th e depressed bon e fragm en t . In th is case, elevat ion of th e fract ure is in dicated. Depressed fract u res crossing du ral ven ou s sin u ses d eser ve sp ecial con siderat ion . W h ile com pression of a du ral ven ou s sin u s m ay in du ce elevated in t racran ial p ressu re an d h eigh ten th e risk of ven ous th rom bosis, th e risk of h em orrh age w ith fract u re m obilizat ion m ay also be sign i can t . Th erefore, it is reason able to obser ve a n eurologically st able pat ien t w ith a closed fract u re overlying a du ral ven ous sin u s. Likew ise, scalp debridem en t alon e (w ith out fract ure elevat ion ) is an opt ion for a n eu rologically stable p at ien t w ith an op en fract u re overlying a paten t sin us. A n eu rologically un st able pat ien t , h ow ever, sh ou ld u n dergo elevat ion u rgen tly.
•
•
lacerat ion s. Th is in cludes adm in ist rat ion of tet an u s toxoid an d broad-sp ect ru m an t im icrobial p rophylaxis. If elevated intracranial pressure is suspected, additional m anagem ent, in accordance w ith traum atic brain injury (TBI) guidelines, is recom m en ded. This m ay include hyperosm olar therapy. An t iepilept ic drug (AED) prophyla xis is appropriate for th e p reven t ion of early seizu res in th e set t ing of TBI, w ith in t racran ial path ology iden t i ed on CT im aging.
Operative Field Preparation • Lim ited clip ping of local h air is reason able for a closed, com -
• • • •
p ressed fract ure. A w ider approach m ay be n ecessar y in th e set t ing of an op en , com pou n d fract u re w ith an t icip ated or kn ow n in t racran ial inju r y. St an dard sterile su rgical tech n iqu e is used to prepare th e op erat ive site. In cision s are m arked an d in lt rated w ith 1% lid ocain e w ith 1:100,000 epin eph rin e. Prophylact ic an t ibiot ics are adm in istered. Availabilit y of blood produ cts sh ou ld be dictated by th e t yp e of injur y an d plan n ed surgical in ter ven t ion . Rapid an d sign i can t blood loss is p ossible, for exam ple, in th e set t ing of a su sp ected du ral ven ou s sin u s inju r y.
6
a
Elevation of Depressed Skull Fractures
b
Fig. 6.1a, b Axial CT (a) brain and (b) bone windows dem onstrating a focal comminuted and depressed left frontal skull fracture with associated extra-axial blood and parenchymal contusion.
91
I Cerebral Traum a and Stroke
Operative Procedure Positioning (Fig. 6.2)
92
Figure
Procedural Steps
Pearls
Fig. 6.2
Patient position is dictated by location of injury and planned surgical procedure. In the event of a standard frontotemporoparietal craniotomy, the patient may be positioned supine, w ith the head turned to the contralateral side. An ipsilateral shoulder roll may be placed and the head of the bed elevated slightly. A horseshoe -shaped headrest should be used. 3
• A slightly elevated position m ay improve the surgeon’s view of the injury, but m ay also increase the risk of air em bolism. Head exion should be minimized to avoid obstruction of venous out ow and increased airway resistance.
6
Elevation of Depressed Skull Fractures
Skin Incision (Fig. 6.3a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 6.3
Super cial debridement may be necessary at the planned incision site for open fractures. A (a) linear, (a) inverted horseshoe, or (b) lazy-S incision may be selected, based on the actual fracture location and the presence of a scalp disruption. (b) Scalp lacerations should be excised as an ellipse and incorporated into the incision if possible. A bicoronal incision is preferred for access to depressed fractures in the forehead area.
• When feasible, the incision should be planned posterior to the hairline.
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I Cerebral Traum a and Stroke
Subcutaneous Dissection (Fig. 6.4)
Figure
Procedural Steps
Pearls
Fig. 6.4
Bipolar electrocautery is used for hemostasis. The scalp ap can be separated from the pericranium using a periosteal elevator. The plane betw een pericranium and galea may be developed w ith sharp dissection.
• Where palpable and/or
The temporalis muscle may be exposed and the fascia incised for dissection using monopolar cautery. Well-preserved muscle can be separated from the underlying bone using sharp dissection. The muscle should be re ected inferiorly and secured w ith suture or hook-based retraction.
• For closed fractures, the underlying skull is inspected and loose fragments removed. Contused pericranium in an open fracture is incised, w ith the corresponding clean pericranium elevated to allow for inspection of the bone.
94
visible bony depression is present, the temporalis should be dissected away from the underlying bone with a periosteal elevator. Avoid the use of m onopolar electrocautery in these areas. Any impacted fragm ents that m ay be com pressing or lacerating dura are not yet rem oved at this stage.
6
Elevation of Depressed Skull Fractures
Craniectomy (Fig. 6.5a–c)
b
a
c
Figure
Procedural Steps
Pearls
Fig. 6.5
(a) A standard, high-speed neurosurgical drill is used to create several points of trephination in the normal bone lateral to the rim of the depressed bone. (b) In the setting of an open fracture, a larger craniectomy that incorporates the traumatic fracture line may be planned. (c) Leksell rongeurs (or a matchstick bur) can be used to complete a circumferential craniectomy, maintaining a margin of normal bone around the area of depression. Free bone fragments are carefully removed and discarded.
• Bone edges are waxed. Salvageable bony fragm ents should be soaked in antibiotic solution before being reassembled.
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I Cerebral Traum a and Stroke
Depressed Fracture Elevation and Exploration of Dural Tears 4 (Fig. 6.6)
Figure
Procedural Steps
Pearls
Fig. 6.6
The depressed bone is elevated w ith a no. 1 Pen eld. Epidural hematoma, if present, is evacuated. Bleeding dural vessels are cauterized. Any area of dural penetration should be explored. This may require extension of the dural defect to permit adequate visualization of the subdural space and cortex. If the dural tear cannot be approximated primarily, interposition of a pericranial graft may be necessary.
• Autograft m ay be preferable
• Holes are drilled circumferentially at the periphery of the craniectomy defect. Epidural tacking stitches are placed w ith 4-0 braided nylon sutures.
96
to allograft for dural repair in the set ting of an open fracture given presumed contam ination of the wound and increased risk of infection. “Ping pong”-t ype depressed skull fractures in the pediatric population can be elevated with gentle aspiration using a breast m ilk extractor.
6
Elevation of Depressed Skull Fractures
Venous Sinus Repair (Fig. 6.7a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 6.7
If injury to the superior sagittal sinus is identi ed, management is dictated by anatomic considerations.
• Depressed fractures with
(a) If initial mechanical maneuvers to achieve hemostasis fail, the anterior one third of the sinus can be ligated w ithout serious adverse e ects. (b) How ever, injury involving the posterior tw o -thirds requires repair w ith a galeal or pericranial patch.
•
potential venous sinus involvem ent m ay require additional preoperative im aging to assess sinus patency and injury. Management of venous sinus injury is discussed in Chapter 10.
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I Cerebral Traum a and Stroke
Calvarial Reconstruction (Fig. 6.8)
Figure
Procedural Steps
Pearls
Fig. 6.8
If explanted bone fragments are not excessively comminuted or contaminated, they may be replaced using a mini-plate and screw xation system.
• Salvageable fragm ents m ay be reassem bled on the back table prior to
If the bone fragments are not salvageable, titanium mesh may be used to bridge the defect.
98
• • •
reimplantation, so as to achieve reasonable cosm esis. Special at tention (and possibly the participation of a plastic surgeon) m ay be required in areas of high visibilit y, such as the orbital rim and forehead. Methyl m ethacrylate should be avoided in children but can be used as a reconstructive adjunct for adults—either to augm ent the reimplanted bony construct or to provide contour if m esh m ust be used to cover larger defects. Absorbable bone plates and screws are recom m ended for pediatric patients. A custom cranioplast y implant is an option for an adult patient with a large cranial defect. However, this does require a second surgical procedure, as well as use of a protective helm et during the interval bet ween injury and receipt of the implant.5
6
Closing • Th e w oun d is irrigated w ith copious am ou n ts of an t ibiot ic • • • • •
solu t ion . Depen ding on t ype of t rau m at ic inju r y, sterile drain age t u bing m ay be im p lan ted an d secu red. Tem poralis m uscle an d fascia are reapproxim ated w ith 2-0 braided nylon sut ures. Th e galea is closed w ith inverted, in terrupted 3-0 braided absorbable su t u res. Th e skin is closed eith er w ith st aples or 3-0 nylon vert ical m at t ress st itch es. A sterile dressing is applied an d accom pan ied by a com pressive h ead w rap , if n ecessar y.
Postoperative Management
Radiographic Imaging • Patients w ith contam inated, open depressed fractures m an -
•
• Depressed fract ure over a venous sinus poses a unique situ-
•
• Post t raum at ic an d postoperat ive m an agem en t are perform ed • •
•
a
aged surgically should be follow ed w ith CT im aging over the 2 to 3 m onth s after initial debridem ent. Clin ical signs/sym ptom s of infection, as w ell as w ound com plications and seizures, m ay prom pt unscheduled CT investigation. Intravenous contrast infusion is indicated if a diagnosis of infection is contem plated. Po sto perative im aging (Fig. 6.9).
Special Considerations
Further Management in accordan ce w ith p ublish ed TBI gu idelin es. Skin su t u res or st ap les m ay be rem oved in 7 to 10 days, dep en ding on t ype of injur y an d w ou n d closu re. Prophylact ic an t ibiot ics are given for 5 to 7 days to lessen th e risk of cen t ral n er vou s system in fect ion . Th e au th ors p refer in t raven ou s cefazolin or piperacillin -t azobact am . How ever, th ere is in su cien t eviden ce to support a speci c agen t or durat ion of th erapy in th is set t ing. An t iconvulsan t s are often given to reduce risk of seizures, alth ough th e su pp or t ing eviden ce is equ ivocal.
Elevation of Depressed Skull Fractures
•
•
ation. A preoperative angiogram w ith venous ow phase, CT ven ogram , or MRA is recom m en ded. The decision to operate is based on the neurologic stat us of the patient, the location of sin us involvem ent, and the degree of venous ow com prom ise. A n eu rologically st able pat ien t w ith a closed, depressed fract ure over a ven ous sin u s can be obser ved. A pat ien t w ith an open , depressed fract ure over a paten t ven ous sin us should u n dergo skin debridem en t w ith out elevat ion of th e dep ressed bon e segm en t . How ever, if th e pat ien t is n eurologically un st able, urgen t elevat ion m ay be required. In the case of sinus throm bosis, the anterior one-third of the superior sagit tal sinus usually can be ligated w ithout consequence. However, injury to the posterior t w o-thirds of the sinus requires either prim ary repair or interposition grafting (w ith a galeal or pericranial patch). Alternatively, a piece of m uscle or gelatin sponge can be sutured over the sinus as a bolster. If the native bone cannot be replaced, either titanium cranioplast y or a polyetheretherketone (PEEK) im plant m ay be considered.
b
Fig. 6.9a, b Axial CT (a) brain and (b) bone windows demonstrating elevation and repair of the depressed skull fracture depicted in Fig. 6.1. An external ventricular drain has been placed to facilitate monitoring of intracranial pressure and therapeutic drainage of cerebrospinal uid.
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References 1. Qu resh i N, Harsh G. Sku ll fract u re. Availab le on lin e at: h t t p :// em e d icin e.m e d scap e.com /ar t icle /248108- ove r view 2. Bullock MR, Chesnut R, Ghajar J, et al. Surgical m anagem ent of depressed cranial fract ures. Neurosurger y 2006;58(3 Suppl):S56–60
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3. Con n olly ES. Fu n dam en t als of Op erat ive Tech n iqu es in Neu rosurger y, 2n d ed. New York: Th iem e Medical Publish ers; 2010 4. Sekh ar LN, Fessler RG. Atlas of Neu rosu rgical Tech n iqu es: Brain . New York: Th iem e Medical Publish ers; 2006 5. March er S, An dres RH, Fath i AR, Fan din o J. Prim ar y recon st ru ct ion of open depressed skull fract ures w ith t it aniu m m esh . J Cran iofac Surg 2008;19(2):490–495
7
Invasive Neuromonitoring Techniques Mathieu Laroche, Michael C. Huang, and Geof rey T. Manley
Introduction Invasive neurom onitoring assists the diagnosis and treatm ent of patients presenting w ith—or at risk for—intracranial hypertension, de ned as intracranial pressure (ICP) greater than 20 m m Hg. A variety of intracranial pathologies such as traum atic brain injury, subarachnoid hem orrhage, intracerebral hem orrhage, and ischem ic stroke (associated w ith m alignant edem a) m ay contribute to an altered level of consciousness and, therefore, an unreliable neurologic exam . Further decline in neurologic status m ay be di cult to detect based on serial clinical evaluation alone. Invasive neurom onitoring can point to signs of deterioration and trigger appropriate interventions. Although ICP m onitoring is m ost com m on, additional advanced m odalities for the m onitoring of brain tissue oxygen tension, m icrodialysis, cerebral blood ow, and jugular venous saturation can help the practitioner achieve a m ore com prehensive understanding of pathologic cerebral physiology and, in turn, provide individualized treatm ent w ith targeted therapies.
Monitoring of Brain Tissue Oxygen Tension, Jugular Venous Saturation, and/or Cerebral Blood Flow 3 • An cillar y m on itoring of cerebral physiology m ay facilitate •
Microdialysis 4 • An cillar y m on itoring of cerebral m et abolic param eters m ay •
Indications Monitoring of ICP by External Ventricular Drain or Intraparenchymal Pressure Probe 1 • Diagn osis an d t reat m en t of in t racran ial hyper ten sion ◦ An extern al ven t ricu lar drain (EVD) is con sidered th e gold
•
stan dard for ICP m easu rem en t . Placem en t of an EVD allow s both for diagn ost ic m on itoring of ICP an d th erapeut ic drain age of cerebrospin al uid (CSF). ◦ An in t rap aren chym al p ressu re m on itor ( beropt ic or m icro st rain gauge device) allow s for m on itoring of ICP alon e. Th e in t raparen chym al probe m ay be coupled w ith oth er n eurom on itoring m odalit ies in a m ult ip or t bolt app arat us or used in isolat ion . As per publish ed guidelin es, in dicat ion s for ICP m on itoring in th e set t ing of severe t raum at ic brain injur y (TBI) 2 ◦ Glasgow Com a Scale (GCS) score 8 after resuscitation, in com bination w ith an abnorm al head com puted tom ography (CT; hem atom a, contusions, swelling, herniation, com pressed basal cisterns) (Level II recom m endation) ◦ GCS 8 after resuscitat ion , w ith a n orm al h ead CT, an d associated w ith t w o or m ore of th e follow ing on adm ission (Level III recom m en dat ion ): ▪ Age . 40 years ▪ Un ilateral or bilateral m otor post uring ▪ Systolic blood pressure , 90 m m Hg
cerebral perfusion pressu re (CPP) m an agem en t in severe TBI w ith loss of au toregulat ion (Level III recom m en dat ion ). Th e brain t issue oxygen ten sion probe usu ally is placed in th e less injured cerebral h em isph ere for m ore con sisten t m easu rem en t an d early detect ion of secon dar y brain inju r y.
facilitate CPP an d brain -sp eci c m an agem en t in severe TBI (Level III recom m en dat ion ). Placem en t of th e m icrodialysis cath eter is dictated by th e speci c p ath ology: ◦ In th e righ t fron tal lobe of p at ien t s w ith di u se brain inju r y. ◦ In th e pericon t u sion al t issu e (p en u m bra) in pat ien t s w ith a focal m ass lesion ; a secon d p robe m ay be placed in un injured or “n orm al” t issue for com p arison . ◦ In th e region of th e brain at risk of vasosp asm follow ing severe su barach n oid h em orrh age.4
Preprocedure Considerations Radiographic Imaging • Non con t rast h ead CT sh ou ld be review ed for: ◦ Size of th e ven t ricular system ◦ In t raven t ricu lar h em orrh age ◦ Mass e ect or focal lesion ◦ Sku ll fract u res ◦ Distan ce from th e bon e to th e fron tal h orn (for EVD placem en t)
Coagulation Parameters • In tern at ion al n orm alized rat io (INR), p ar t ial th rom boplast in •
t im e (PTT), an d platelets sh ould be in n orm al range. In t h e coagu lop at h ic p at ien t , con sid er t ran sfu sion of p latelet s, fresh frozen p lasm a (FFP), an d /or p rot h rom bin com p lex con cen t rate—as ap p rop r iate—before t h e p roced u re.
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Availablity of All Necessary Equipment • Placem en t can be perform ed eith er in th e operat ing room or at th e bedside (m ost com m on ly).
Medication • Lidocain e 1%w ith epin ep h rin e 1:100,000 for local an esth esia • Midazolam or prop ofol for sedat ion • Fen t anyl for an algesia
• Elevate th e h ead of th e bed ap p roxim ately 30 degrees. • Clip h air overlying th e fron tal quadran t using an elect ric razor. • Iden t ify im port an t an atom ic lan dm arks: ◦ Midlin e ◦ Nasion ◦ Mid-p u p illar y lin e ◦ Extern al auditor y can al ◦ Coron al sut ure (by palpat ion ) • Iden t ify th e app roxim ate locat ion of Koch er’s p oin t by on e of
Operative Field Preparation for Intracranial Neuromonitoring
•
• Posit ion th e h ead in th e n eu t ral posit ion (a rigid C-collar,
•
bean bag, or xat ion w ith t ape are e ect ive w ays to ach ieve th is at th e bedside).
•
th e follow ing st rategies: ◦ 11 cm posterior to th e n asion an d 3 cm lateral to m idlin e ◦ 1 cm an terior coron al sut ure an d 3 cm lateral to m idlin e ◦ In tersect ion of th e m idpu pillar y lin e w ith a p erp en dicu lar lin e exten ding from th e m idpoin t of an im agin ar y lin e con n ect ing th e extern al can th us to th e t ragus In lt rate th e skin at th e p lan n ed in cision site w ith 1% lidocain e w ith epin eph rin e 1:100,000. Prepare th e skin w ith alcoh ol before applicat ion of proviodin e iodin e or ch orh exidin e. Anato m ic landm arks fo r placem e nt o f EVD (Fig. 7.1).
a Fig. 7.1a–c Multiple measurement strategies have been proposed to determine the optim al entry point for insertion of an EVD (or comparable invasive monitor): (a) 11 cm posterior to the nasion and 3 cm lateral to midline, (continued)
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b
c Fig. 7.1a–c (continued) (b) 1 cm anterior to coronal suture and 3 cm lateral to midline, and (c) intersection of the midpupillary line with a perpendicular line extending from the midpoint of an imaginary line connecting the external canthus to the tragus.
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Operative Procedure Placement of Intracranial Monitors Positioning (Fig. 7.2)
Figure
Procedural Steps
Pearls
Fig. 7.2
The head is maintained in the neutral position w ith the head of bed at 30 degrees.
• The operator stands behind the patient. • A C-collar or bean bag is useful to m aintain the head in the •
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neutral position. EKG electrodes can be placed on the nasion and tragus for easier palpation of the landm arks after draping.
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Skin Incision (Fig. 7.3)
Figure
Procedural Steps
Pearls
Fig. 7.3
A small stab incision is made at the planned entry site and extended through the scalp to the level of bone.
• • • •
For EVD: at Kocher’s point. For brain tissue oxygen: 1 to 2 cm behind Kocher’s point. For cerebral blood ow : 1 to 2 cm in front of Kocher’s point. If advanced neurom onitoring probes are too close to the EVD, or each other, they m ay not provide accurate and reliable inform ation.
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Tw ist Drill Craniostomy (Fig. 7.4)
Figure
Procedural Steps
Pearls
Fig. 7.4
Using the tw ist drill, a small craniostomy is performed, follow ed by copious irrigation to remove blood and bone debris.
• An assistant is helpful to stabilize the head during drilling to m aintain neutral positioning. • •
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As a general rule, each cannulation system com es equipped with a proprietary drill bit. For an EVD, a 5.3-m m drill bit is provided. If available, a drill safet y stop should be used. It is important to perform the craniostomy absolutely perpendicular to the plane of the skull. The trajectory m ay be assisted by aim ing at the ipsilateral inner canthus in the coronal plane and just anterior to the tragus in the sagit tal plane or with the use of a tripod device. The operator is able to feel a change in the resistance as the drill travels through the outer cortex (hard), diploe (soft), and inner cortex (hard). The operator should slow down as more resistance is felt while the drill penetrates into the inner cortex to avoid plunging into the brain tissue. After rem oving the t wist drill, the dura can be palpated using a spinal needle or a small blunt instrum ent.
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Variation for Bolt-type Monitors (Fig. 7.5)
Figure
Procedural Steps
Pearls
Fig. 7.5
If a bolt-based system is being used, the bolt should be screw ed into the craniostomy site to nger tightness.
• The dura then is punctured by passage of the central st ylet. The beroptic pressure monitor or EVD catheter is threaded through the central opening in the bolt to the desired depth. The cu is tightened and the locking sheath pulled over top to secure the system .
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Opening of Dura and Leptomeninges (Fig. 7.6)
Figure
Procedural Steps
Pearls
Fig. 7.6
The dura is punctured using a 18-gauge spinal needle or a 14-gauge needle.
• A loss of resistance will be felt when the dura is perforated using •
The pia is perforated using the spinal needle or a no. 11 blade.
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•
the needle. Multiple punctures m ight be necessary to open the dura completely. For brain tissue oxygen m onitors: The dura m ust be opened completely beneath the craniostomy to avoid dam aging the electrode tip. To achieve a bet ter result, a no. 11 blade is used to open the dura in a cruciate m anner, under direct visualization. A slight y larger skin incision m ay be necessary. A good pial opening is essential to m inim ize the risk of subdural placem ent of neurom onitors.
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Variation for External Ventricular Drain (Fig. 7.7)
Figure
Procedural Steps
Pearls
Fig. 7.7
The ventricular catheter—w ith stylet—is inserted slow ly to a maximal depth of 6 cm from the outer table of the bone. When the frontal horn is cannulated, a slight increase in resistance, follow ed by a loss of resistance (a “pop”), is classically felt. The stylet then is removed. There should be clear CSF drainage from the ventricular catheter.
• The ipsilateral frontal horn should be punctured at a depth of
• •
3 to 5 cm from the inner table of the bone with the catheter oriented perpendicular to the bone and targeted at the inner canthus of the ipsilateral eye in the coronal plane and just in front of the tragus in the sagit tal plane.5,6 If the ventricle is not cannulated after three at tempts, the ventricular catheter should be left in place and its position veri ed with a head CT. EVD placement is m ore di cult in patients with sm all ventricles. In this situation, adjuncts such as a tripod (a sm all device that ensures that the catheter is perpendicular to bone),7 neuronavigation, and ultrasound m ay be considered to assist accurate catheter positioning.
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Tunneling and Securing the Cathether (Fig. 7.8a, b)
a
110
b
Figure
Procedural Steps
Pearls
Fig. 7.8
(a) Using a trocar, the ventricular catheter is tunneled about 5 cm from the incision.
• Secure the Luer lock connection with a 2-0 silk tie.
(b) After removing the trocar, a Luer lock and cap are applied. The EVD is secured to the skin at multiple points w ith 3-0 nylon stitches.
• A gentle loop of the external portion of the catheter perm its stay sutures at 3, 6, 9, and 12 o’clock. Failure to secure the EVD adequately to the patient may leave the system vulnerable to unintended, traumatic explantation.
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Variations for Monitor Placement (Fig. 7.9)
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Figure
Procedural Steps
Pearls
Fig. 7.9
The beroptic ICP probe is zeroed w ith respect to air.
• To zero the probe, follow the individual m anufacturer’s instructions.
Intraparenchymal Monitor The probe then is introduced into the central opening of the bolt apparatus and advanced into the brain parenchyma—deep enough to obtain a reliable ICP measurement (no more than 2.5 cm). The pressure probe then is secured to the bolt system or tunneled and secured to the skin depending on the system.
• Visualization of the ICP waveform during insertion can assist
Variation for Brain Tissue Oxygen Monitor After ensuring that the dura and the pia are opened, the inner sleeve is inserted into the bolt. The brain tissue oxygen probe, in turn, is inserted through the inner sleeve into its predetermined port. The inner sleeve then is secured to the bolt by a screw.
• There should be no resistance when the inner sleeve and the
Variation for Cerebral Blood Flow Monitor After connecting to the monitor, the cerebral blood ow probe is inserted into the w hite matter (2 to 2.5 cm deep to the dura, into the centrum semiovale). The probe is secured to a bolt or tunneled and secured to the skin. Variation for Microdialysis Cathether The microdialysis probe is inserted into the parenchyma to a depth of about 2 cm, depending on the region of interest. It is secured to the skin after tunneling, or it can be secured through a bolt system. 8
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•
in the placem ent. If no waveform or an unexpectedly high pressure is observed, rem ove the probe temporarily, reassess the patency of the dural opening, and consider irrigation with a sm all am ount of sterile saline. The ICP m onitor can be tested after insertion with brief bilateral m anual compression of the jugular veins (Queckenstedt m aneuver). This m aneuver reduces venous out ow and, thereby, increases ICP.
brain tissue oxygen probe are inserted if the dura is widely open and the pia has been pierced. Any signi cant resistance during placem ent of the inner sleeve indicates a need for wider dural opening. Resistance during probe placem ent could m ean that the probe is m igrating in the epidural space or sliding over the brain. An FiO2 challenge (rapid increase in inspired oxygen to 100%) should be used to verify that the probe is functioning.
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Placement of Jugular Venous Saturation (SjVO2 ) Monitor Positioning (Fig. 7.10)
Figure
Procedural Steps
Pearls
Fig. 7.10
The patient is positioned in a slight Trendelenburg position to distend the jugular vein. The entire neck and the upper thorax are prepped and draped.
• Retrograde catheterization of the internal jugular vein is accomplished using the sam e Seldinger technique as for the placem ent of central venous catheters.
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Skin Incision and Insertion (Fig. 7.11)
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Figure
Procedural Steps
Pearls
Fig. 7.11
The puncture site is medial to the sternocleidomastoid muscle, about 3 cm lateral and 2 cm above the medial border of the clavicle. After the internal jugular vein is cannulated, the Seldinger technique is used to advance the introducer sheath. The medial and distal port of the beroptic catheter are ushed w ith a heparinized solution and the catheter is advanced to a depth of 16 to 18 cm.
• The needle m ust be advanced from the insertion point toward
• •
the external auditory m eatus under constant aspiration with a 30-degree angle in the sagit tal plane. When the internal jugular vein is cannulated, there will be a blush of dark blood and a loss of resistance. The guidewire should not be introduced m ore than the intended length of the beroptic catheter (16 to 18 cm ). An ultrasound device can be helpful in identi cation and cannulation of the vessels.
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Veri cation of Position (Fig. 7.12)
Figure
Procedural Steps
Pearls
Fig. 7.12
Anteroposterior (AP) and lateral skull X-rays are obtained to verify position. In this representative lateral X-ray, the tip of the catheter is denoted by the arrow.
• The tip of the beroptic catheter should be high in the jugular bulb to m axim ize the likelihood of m easuring the venous blood draining from the brain and to m inim ize contam ination from extracranial blood. X-ray veri cation is recom m ended to ensure that the tip of the catheter is just m edial to the base of the m astoid bone in the AP plane and at the lower portion of C1 in the lateral plane. The position of the catheter can also be veri ed with a head CT, where it should be seen in the jugular foram en at the base of the skull.
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Closing • Th e in cision site is irrigated. Th e skin in cision is closed w ith • •
3.0 nylon sut ures. A sterile t ran sp aren t dressing is placed over th e in cision site (or arou n d th e bolt apparat us). Calibrat ion ◦ EVD: after cath eter placem en t , th e drain h eigh t is selected (in cm H2 O). Th e drain age system is set w ith th e zero poin t level to th e top of th e pat ien t’s ear. Th is correspon ds to th e ap proxim ate level of th e foram en of Mon ro—th e m idp oin t of th e vent ricular system . Th e pressure w aveform m ay be record ed by at t ach m en t to an extern al st rain gauge or by in ser t ion of a beropt ic pressure probe or m icro st rain gauge d evice in to th e EVD lu m en (an d con n ect ion to a stan d-alon e m on itor box). ◦ Parenchym al ICP m onitor: the beroptic pressure probe is at tached to a stand-alone m onitor box and zeroed w ith respect to air prior to insertion into the seated bolt apparatus. ◦ Brain tissue oxygen m o nito r: Calibrat ion is ach ieved th rough th e use of a sm artcard. ◦ Cerebral blood f ow m onitor: To ensure that the probe is op tim ally placed, the K value on the m onitor should be between 4.8 and 5.6 and the probe position assistant (PPA) below 2. The K value varies depending on the conductivity of the tissue. The K value of w hite m atter is between 4.8 and 5.9. PPA indicates the artifact created by the pulsation of the brain tissue (if the probe is close to a vessel). A value of 0 indicates no artifact. ◦ Jugular ve no us saturatio n m o nito r: On ce correct probe posit ion h as been veri ed, ligh t in ten sit y calibrat ion of th e oxim et r y system can be p erform ed. A blood sam p le from th e t ip of th e cath eter is also sen t for an alysis to con rm th e value on th e oxim et r y system . Frequen t recalibrat ion is requ ired an d sh ou ld be prom pted by any su dden ch ange in th e jugu lar ven ous sat urat ion —p rior to any alterat ion of m edical m an agem en t .
Radiographic Imaging • It is com m on pract ice to p erform a p ost-procedu re n on con •
•
Further Management • Advan ces in th e elds of n eu roin ten sive care an d m u lt im odal
•
Postoperative Management Monitoring • Patients for w hom invasive neurom onitoring is indicated generally w ill be housed in the intensive care unit setting. The m ajorit y w ill be intubated. Intensive adjunctive m onitoring w ith a com bination of frequent neurologic checks, an arterial line, a central venous catheter, telem etry, pulse oxim etry, and, in som e cases, end-tidal CO2 capnography is routine in this population.
Medication • Sedat ion w ith prop ofol or dexm edetom id in e is preferred •
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because th e sh or t-act ing n at ure of th ese agen ts perm it s serial assessm en t of n eu rologic st at u s. A p rophylact ic dose of an t ibiot ics (cefazolin , or clin dam ycin in th e set t ing of allergy to pen icillin ) sh ou ld be adm in istered w ith in th e h our prior to skin in cision for m on itor placem en t .
t rast h ead CT in order to verify th e posit ion of th e probe(s) an d to exclu d e iat rogen ic h em orrh age. Most invasive in t racran ial m on itors, w ith th e except ion of th e extern al ven t ricular drain , are n ot MRI-com pat ible. For fu rth er in form at ion , refer to th e m an u fact u rer gu idelin es for th e speci c device. Po stpro ce dure CT im aging (Fig. 7.13).
•
n eu rom on itoring h ave sign i can tly ch anged th e m an agem en t of severe t rau m at ic brain injur y (TBI) in th e last t w o decades. Sin ce 1995, th e Brain Traum a Foun dat ion h as publish ed m an agem en t gu idelin es for th e t reat m en t an d p reven t ion of in t racran ial hyp erten sion (ICP . 20 m m Hg) an d th e m ain ten an ce of adequ ate CPP (50 to 70 m m Hg) in order to m in im ize secon dar y inju ries. Th e u se of advan ced n eu rom on itoring m odalit ies su ch as th e brain t issu e oxygen , cerebral blood ow, an d m icrodialysis probes sh ou ld be con sidered in cases w h ere cerebral autoregulat ion is com prom ised. W h en used ap prop riately, th ese addit ion al m on itors m ay p rovide a m ore com preh en sive un derst an ding of th e altered physiology an d en able in dividu alized, t argeted th erapy. Cerebral tissue oxyge n (PbtO2 ) is m easured by a sm all, polarograph ic, Clarke-t ype in t raparen chym al probe th at records th e part ial pressure of brain t issue oxygen ten sion . It is u su ally in serted in n on inju red w h ite m at ter, aw ay from any con t u sion , to perm it an est im ate of “global” cerebral physiology an d ser ve as an early detect ion system for secon dar y brain injur y. Accurate, real-t im e m easurem en ts can be obtain ed 1 to 2 h ours after insert ion . Th e frequen cy an d durat ion of cerebral desat u rat ion episodes—de n ed as PbtO2 less th an 15 m m Hg—correlate w ith ou tcom e. Alth ough th ere seem s to be a t ren d tow ard bet ter ou tcom e w ith PbtO2 targeted th erapy to preven t an d agressively t reat episodes of subth resh old PbtO2 , it is u n clear w h eth er a h igh er PbtO2 o ers any ben e cial e ect for th e pat ien t .3,9–11 Mon itoring of PbtO2 also h igh ligh t s th e in terd ep en den ce of brain t issu e oxygen ten sion an d p u lm on ar y fu n ct ion . Before at t ribu t ing a low PbtO2 to a reduct ion in cerebral blood ow, it is n ecessar y to exclud e any ext racran ial con dit ion s th at cou ld n egat ively im pact blood oxygen at ion , such as lung con t u sion s, acu te resp irator y dist ress syn drom e, p n eu m on ia, atelect asis, or an em ia. Adjun ct ive diagn ost ic m odalit ies—arterial blood gas (ABG), com p lete blood cou n t (CBC), ch est X-ray, an d FiO2 ch allenges—m ay h elp to elucidate th e un derlying cause of an obser ved desat u rat ion . Moreover, th e posit ion of th e probe sh ou ld be assessed before in it iat ing m ore aggressive t reatm en t s. Im p roper p robe p osit ion ing in th e ep idu ral sp ace, in a su lcu s, in th e cortex, or adjacen t to con t u sed brain can cau se erron eou s read ings. Jugular veno us saturatio n m o nito r (SjVO2 ): Ret rograde can n ulat ion of th e dist al por t ion of th e in tern al jugular vein perm it s a “global” m easurem en t of th e oxygen deliver y to th e brain . Norm al SjVO2 ranges bet w een 55 an d 70%. A low
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a
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b
d
e
Fig. 7.13a–e Normal appearance of the indwelling blood ow and cerebral tissue oxygen probes, as well as the EVD catheter, at the level of the left frontal lobe (a, bone window; b, brain window). From anterior to posterior: cerebral blood ow, EVD, and cerebral tissue oxygen. (c, e) Optimal positioning of the EVD catheter in the right anterior horn, near the foramen of Monro, and (d) the cerebral brain tissue oxygen probe in the white mat ter of the right frontal lobe.
sat u rat ion (, 50%) h as been correlated w ith isch em ia an d w orse ou tcom e after severe TBI, w h ereas a h igh valu e (. 80%) m ay correlate eith er w ith hyp erem ia (w h ere in creased ow redu ces th e sat u rat ion di eren ce) or w ith brain death (w h ere im p aired m etabolism an d t issue death redu ce th e sat urat ion di eren ce). Th e obser ved value is sen sit ive to th e posit ion of th e cath eter. Con t am in at ion by ext racerebral ven ous blood, for exam p le, w ill lead to a low er valu e.12,13 As w ith brain t issu e oxygen m on itoring, p oten t ial system ic cau ses (hypoxia, hypoten sion , hypocarbia, an em ia) m ust be ruled out w h en a low valu e is obser ved. Alth ough m u ch con t roversy exists regarding th e opt im al sid e for p lacem en t of th e SjVO2 probe, it is t yp ically in ser ted on th e righ t side becau se th e righ t t ran sverse sin u s is th e m ost frequ en tly th e dom in an t site for th e ven ou s drain age of th e brain . Th e jugu lar ven ou s sat u rat ion m on itor, w h en u sed in com bin at ion w ith th e PbtO2 probe, p rovides both a global (SjVO2 ) an d a focal (PbtO2 ) assessm en t of brain t issue oxygen at ion . Th is com bin at ion allow s for th e dist in ct ion bet w een hyperem ia an d h ardw are failure if a valu e seem s to be ou t of range. Moreover, th e t an dem u se of SjVO2 an d PbtO2 m ay facilitate m odi cat ion of th erapy to opt im ize CPP in th e set t ing of im paired autoregulat ion . Th e
•
•
p ract it ion er sh ould be aw are th at th e m easurem en t of SjVO2 is ext rem ely labor in ten sive because of th e frequ en t n eed to assess th e p osit ion of th e p robe an d to com pare blood sam ples obtain ed from th e t ip of th e cath eth er to th e valu es ob t ain ed by oxim et r y. Cerebral blo o d f ow (CBF) m o nitoring: An in t rap aren chym al p robe m easu res th e local blood ow u sing a th erm al di usion tech n ique. Th e probe is in serted in th e w h ite m at ter (n orm al CBF 20–35 m L/100 g/m in ). A valu e of less th en 9 m L/100 g/m in in dicates a degree of isch em ia th at w ill lead to irreversible cellular dam age. It is im port an t to n ote th at th e m easu red valu e re ects th e st at u s of on ly th e sm all, sph erical volu m e of brain t issue (27 m m 3 ) aroun d th e cath eter t ip an d th at th e m easurem en t is ext rem ely probe posit ion depen den t .14–16 Proxim it y of th e probe to inju red t issu e w ill produ ce a low er CBF valu e as com pared w ith th at m easured by a probe position ed w ith in n orm al-appearing cor tex. Micro dialysis: A m icrodialysis p robe allow s for th e st u dy of th e brain t issue ch em ist r y th rough m easurem en t s of cerebral m et abolism . Glucose, pyruvate, an d lact ate are m arkers of en ergy m et abolism . Glutam ate an d glycerol are m arkers for n eu ron al inju r y. Th e rat io of lact ate to pyruvate correlates
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I Cerebral Traum a and Stroke w ith th e severit y of clin ical sym ptom s an d outcom e after brain injur y. Microdialysis h as been used in th e set t ing of severe TBI an d su barach n oid h em orrh age to p redict isch em ia an d vasosp asm .4 Th e use of m icrodialysis is labor in ten sive an d n ecessitates a h igh ly t rain ed team . Resu lts w ill d i er depen ding on w h eth er th e probe is posit ion ed w ith in n orm al or con t used t issue.17
Special Considerations ICP rem ain s th e corn erston e of invasive brain m on itoring. Advan ced n eu rom on itoring tech n iqu es p rovide an op port u n it y for bet ter u n derstan ding of cerebral path ophysiology; h ow ever, e ect ive u se of th is tech n ology requ ires an u n d erst an ding of h ow to both properly p lace th e p robe an d in terpret th e dat a. Dat a derived from th ese m odalit ies are ext rem ely depen den t on th e posit ion of each probe. Th erefore, veri cat ion of probe posit ion is essen t ial prior in it iat ing sign i can t ch anges in clin ical m an agem en t . Fu rth erm ore, pat ien t s requiring su ch m on itoring t yp ically are com p lex an d m ay p resen t w ith a variet y of cerebral path ophysiologic abn orm alit ies. Th e pract it ion er m ust possess a deep an d clear un derst an ding of cerebral physiology an d m et abolism in order to u se th e in form at ion e ect ively in th e pat ien t-speci c t reat m en t of TBI. In sum m ar y, w h ile th ere does exist a role for th e use of advan ced n eu rom on itoring tech n iques, th e resu lt s m ust be in terp reted an d ap plied crit ically.
References 1. Brat ton SL, Ch est n u t RM, Gh ajar J, et al. Gu idelin es for th e m an agem en t of severe t rau m at ic brain injur y. VII. In t racran ial pressure m on itoring tech n ology. J Neu rot raum a 2007;24 Suppl 1:S45–54 2. Brat ton SL, Ch est n u t RM, Gh ajar J, et al. Gu idelin es for th e m an agem en t of severe t raum at ic brain injur y. VI. Indicat ion s for in t racranial pressu re m on itoring. J Neurot raum a 2007;24 Suppl 1:S37–44 3. Brat ton SL, Ch est n u t RM, Gh ajar J, et al. Gu idelin es for th e m an agem en t of severe t raum at ic brain inju r y. X. Brain oxygen m on itoring an d th resh old s. J Neu rot rau m a 2007;24 Su p pl 1:S65–70
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4. Bellan der BM, Can t ais E, En blad P, et al. Con sen su s m eet ing on m icrodialysis in neu roin ten sive care. In ten sive Care Med 2004;30(12):2166–2169 5. O’Lear y ST, Kole MK, Hoover DA, Hysell SE, Th om as A, Sh a rey CI. E cacy of th e Gh ajar Guide revisited: a prospect ive st udy. J Neu rosurg 2000;92(5):801–803 6. Tom a AK, Cam p S, Watkin s LD, Grieve J, Kitch en ND. Extern al ven t ricu lar drain in ser t ion accu racy: is th ere a n eed for ch ange in pract ice? Neurosurger y 2009;65(6):1197–1200; discussion 1200–1191 7. Gh ajar JB. A gu ide for ven t ricu lar cath eter p lacem en t . Tech n ical n ote. J Neurosu rg 1985;63(6):985–986 8. Poca MA, Sah u qu illo J, Vilalt a A, d e los Rios J, Robles A, Exp osito L. Percut an eous im plan t at ion of cerebral m icrodialysis cath eters by t w ist-drill cran iostom y in n eurocrit ical pat ien t s: descript ion of th e tech n ique an d resu lt s of a feasibilit y st udy in 97 pat ien t s. J Neu rot raum a 2006;23(10):1510–1517 9. Narot am PK, Morrison JF, Nath oo N. Brain t issu e oxygen m on itoring in t rau m at ic brain inju r y an d m ajor t rau m a: ou tcom e an alysis of a brain t issue oxygen -directed th erapy. J Neurosurg 2009;111(4):672–682 10. Rose JC, Neill TA, Hem p h ill JC, 3rd. Con t in u ou s m on itoring of th e m icrocircu lat ion in n eurocrit ical care: an update on brain t issue oxygen at ion . Cu rr Op in Crit Care 2006;12(2):97–102 11. Spiot t a AM, St iefel MF, Gracias VH, et al. Brain t issu e oxygen directed m an agem en t an d ou tcom e in pat ien t s w ith severe t rau m at ic brain injur y. J Neurosurg 2010;113(3):571–580 12. Fan din o J, Stocker R. Cath eterizat ion of th e in tern al jugu lar vein for jugular bulb oxygen sat urat ion m on itoring after brain injur y. J In ten Care Med 1999;14:270–290 13. Bh at ia A, Gu pt a AK. Neu rom on itoring in th e in ten sive care u n it . II. Cerebral oxygen at ion m on itoring and m icrodialysis. In ten sive Care Med 2007;33(8):1322–1328 14. Jaeger M, Soeh le M, Sch u h m an n MU, Win kler D, Meixen sberger J. Correlat ion of con t in u ously m onitored region al cerebral blood ow an d brain t issue oxygen . Act a Neuroch ir (Wien ) 2005;147(1):51–56; discussion 56 15. Bh at ia A, Gu pt a AK. Neu rom on itoring in th e in ten sive care u n it . I. In t racran ial pressure an d cerebral blood ow m on itoring. In ten sive Care Med 2007;33(7):1263–1271 16. Vajkoczy P, Roth H, Horn P, et al. Con t in u ou s m on itoring of region al cerebral blood ow : experim en t al an d clin ical validat ion of a n ovel th erm al di usion m icroprobe. J Neurosurg 2000;93(2):265–274 17. Engst rom M, Polito A, Rein st ru p P, et al. In t racerebral m icrodialysis in severe brain t raum a: th e im por t an ce of catheter locat ion . J Neu rosu rg 2005;102(3):460–469
8
Surgical Debridement of Penetrating Injuries Roland A. Torres and P.B. Rak sin
Introduction
Indications
Alth ough open h ead inju ries are com m on ly referred to as penet rat ing, n ot all su ch inju ries are alike. Th e term penet rat ing inju r y tech n ically describes th e sit uat ion in w h ich a project ile en ters th e sku ll bu t does n ot exit . A perforat ing injur y occurs w h en th e project ile passes en t irely th ough th e h ead, leaving both an en t ran ce an d an exit w oun d. Th is dist in ct ion h as progn ost ic im plicat ion s. In a series of project ile-related h ead inju ries du ring th e Iran -Iraq War, p at ien ts t reated for perforating w ou n d s h ad a poorer post su rgical outcom e (50% greater m orbidit y an d m ort alit y) th an th ose t reated for p en et rat ing w ou n ds.1 Pen et rat ing h ead inju ries m ay resu lt from in ten t ion al or un in ten t ion al even ts, in clud ing sh oot ings, st abbings, blast in ju ries, an d m otor veh icle or occup at ion al acciden t s (e.g., n ails). Stab w ou n ds are ch aracterized by a sm aller im pact area an d low er velocit y th an m issile w oun ds. For th e p urp oses of th is chapter, w e lim it ou r discussion to m issile w oun ds. Historically, th e m an agem en t of civilian m issile inju ries h as been in form ed by an d evolved in con cer t w ith m ilit ar y pract ice. Sin ce World War II, m ilitar y n eurosurgeon s h ave un iform ly advocated th orough debridem en t an d w ater t igh t du ral closu re to preven t cerebrosp in al u id (CSF) leak an d p ossible in fect ion . During th e Viet n am War era, cran iectom y or cran iotom y w as accom pan ied by aggressive d ebridem en t of th e in -driven bon e, project ile fragm en t s, an d associated debris. Th e pursuit of debris in to areas of poten t ially viable brain t issue w as believed to be respon sible for addit ion al n eu rologic de cit s an d im pairm en t .2,3 Part ially in respon se to th is n ding an d as th e result of experien ce glean ed from m ult iple m ilitar y con icts over th e past 40 years, a n ew m an agem en t paradigm h as em erged. In it ial t reatm en t of project ile w oun ds of th e brain is n ow design ed to p reser ve th e m axim u m cerebral t issu e an d fu n ct ion eith er by lim it ing th e w ou n d debridem en t p erform ed th rough a cran iectom y or by care of scalp w ou n ds on ly.4–6 Branvold et al fou n d n o relat ion sh ip bet w een th e presen ce of ret ain ed fragm en ts an d th e developm en t of eith er a seizure disorder or an in fect ion of th e cen t ral n er vous system .7 Fin dings such as th is on e support th e grow ing con sen su s th at rout in e reoperat ion for rem oval of retain ed fragm en ts is u n n ecessar y. Th e n et result of th is st rategy h as been im p roved ou tcom es w ith sign i can tly d ecreased m orbidit y an d m ort alit y.
• The totalit y of the obser ved injury re ects a com bination of
• •
•
forces: (1) direct crush injur y in icted by the projectile along its path; (2) cavitation produced by the centrifugal e ects of the projectile on the parenchym a; and (3) stretch injury resulting from th e shock wave generated by the projectile in transit. Each m ust be factored into the decision-m aking process. Tw o fun dam en tal decision s drive m an agem en t: (1) w h eth er or n ot to operate an d, if so, (2) th e exten t of th e in ter ven t ion to be un der taken . Th e decision of w hether or not to operate is dict ated both by clin ical st at us an d th e obser ved radiograph ic path ology. ◦ Su pp ort ive, expect an t (n on operat ive) m an agem en t m ay be ap p rop riate for a pat ien t p resen t ing w ith a Glasgow Com a Scale (GCS) score 5 an d bilateral xed, dilated pupils post-resuscit at ion . ▪ If such a patient presents w ith a potentially reversible m ass lesion and is deem ed otherw ise m edically viable, consideration m ay be given to em ergent operative intervention. ▪ If n o ext ra-axial m ass lesion is presen t , con siderat ion m ay be given to a t rial of hyperosm olar th erapy (20% m an n itol bolus 1 g/kg); if a sign i can t im provem en t in m otor exam an d/or pu pillar y respon se is n oted , th e p at ien t m ay be con sidered a poten t ial can didate for surger y. ◦ Hem odyn am ic in st abilit y an d/or p rofou n d coagu lopathy m ay in u en ce th e d ecision to forego op erat ive in ter ven t ion . ◦ Certain om inous radiographic ndings portend a poor prognosis: anteroposterior or bilateral hem ispheric throughand-through trajector y; or trajectory through the brainstem , hypothalam us, posterior fossa, and/or venous sinuses. These factors should be taken into account w hen determ ining candidacy for operative inter vention. ◦ On th e oth er h an d, a p at ien t p resen t ing w ith a GCS score of 14 or 15 an d m in im al radiograph ic injur y m ay require on ly local w oun d care an d close obser vat ion . Clin ical exam an d radiograph ic feat u res gu ide th e extent of operat ive intervent ion.5,8 ◦ Lim ited su rger y m ay be app ropriate for a pat ien t presen ting w ith a sm all en t ran ce w oun d, coupled w ith m in im ally depressed bon e fragm en t s an d lit tle or n o m ass e ect an d/ or h em atom a on h ead com puted tom ography (CT). Su ch a pat ien t m ay ben e t from super cial debridem en t .9
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•
◦ Craniotom y/craniectom y w ith targeted, lim ited debridem ent
• Non con t rast CT p rovides th e m ost com preh en sive sou rce
m ay be appropriate for a patient presenting w ith lim ited m ass e ect, som e in-driven bone fragm ents, som e projectile fragm ents, and m ild to m oderate cerebral edem a. Only the easily accessible bone and projectile fragm ents should be retrieved. Aggressive adjacent brain debridem ent should be avoided. These patients do very well w ith a com bination of copious intraoperative antibiotic irrigation, form al dural closure, good scalp closure, and periprocedural broad-spectrum antibiotics. ◦ Craniotom y/craniectom y w ith m ore extensive debridem ent is appropriate in the presence of signi cant m ass e ect. Space-occupying lesions should be evacuated. Debridem ent of necrotic brain tissue, along w ith safely accessible bone and m issile fragm ents, is recom m ended.5,10,11 Deep-seated bone and m issile fragm ents—especially in eloquent areas—should not be retrieved because this has been show n to correlate w ith worse outcom es. When the projectile’s trajectory traverses an air sinus, operative intervention is recom m ended to achieve water-tight closure of the dam aged dura.1,9 This m ay decrease the risk of CSF stula and abscess form ation.1,12 No eviden ce-based recom m en dat ion s address th e t im ing of in ter ven t ion . Here, pragm at ism ap plies. ◦ If a sign i can t space-occu pying lesion is p resen t , em ergen t su rgical in ter ven t ion is w arran ted for relief of m ass e ect as a life-saving m easu re—w ith th e recogn it ion th at it m ay n ot ch ange ou tcom e. ◦ If n dings suggest ing m ass e ect are less com p elling, it w ou ld be reason able to m on itor in t racran ial pressu re (ICP) an d m an age expect an tly. ◦ If th e goal is sim ple w ou n d care, it w ou ld follow th at exp edien t in ter ven t ion m ay dim in ish th e risk of in fect ion an d CSF com p licat ion s.9,10
of an atom ic in form at ion . CT w ill reveal th e presen ce of h em atom a an d foreign bodies—both bony an d m et allic—as w ell as in form at ion regard ing th e likely m issile t rajector y. Th e CT sh ould be st udied for poten t ial violat ion of vascular st ru ct u res. If direct vascu lar inju r y is su spected , em ergen cy vascu lar im aging m ay be approp riate. ◦ Im aging n dings arou sing su spicion m ay in clu de: orbitofacial or pterion al locat ion ; t rajector y th rough a ven ous sin us or th e Sylvian ssure; th e presen ce of fragm en t s crossing dural com par t m en t s; or th e presen ce of a large h em atom a proxim ate to a n am ed vessel. ◦ Form al cerebral angiograp hy n ot on ly perm it s d iagn ost ic assessm en t bu t also o ers th e poten t ial for in ter ven t ion . ◦ In recogn it ion of expedien cy, CT angiograp hy m ay be an oth er opt ion in th is set t ing.9 ◦ A single n egat ive st u dy does n ot d e n it ively ru le ou t inju r y. Th e developm en t of un explain ed subarach n oid h em orrh age or h em atom a in th e days follow ing th e in it ial inju r y m ay p rovide an in dicat ion for delayed or rep eat im aging. Magn et ic reson an ce im agin g (MRI) is ge n e rally con t rain d icate d in t h e set t in g of a p e n et rat in g in ju r y w it h m et allic fore ign b od y. How eve r, it sh ou ld b e n ot e d t h at m ost civilian am m u n it ion —p ar t icu larly p istol am m u n it ion —is act u ally n on fe r rom agn et ic an d , h yp ot h et ically, sh ou ld n ot p re clu d e MRI evalu at ion . Cau t ion m u st b e exe rcise d w it h sh ot gu n w ou n d s as m any sh ot gu n sh ells n ow d elive r st e el sh ot (d u e to Environ m e n t al Prote ct ion Age n cy legislat ion regard in g lead p ollu t ion ). MRI m ay p lay a role in t h e d iagn ost ic evalu at ion of p e n et rat in g in ju r ies from w ood e n or n on m agn et ic obje ct s. Ke e p in m in d t h at MRI is n ot p ract ical in t h e acu te set t in g, give n t h e t im e n e cessar y to p e rfor m t h e st u d y as w ell as p ote n t ial r isks associat e d w it h t ran sp or t in g a cr it ically ill p at ie n t to an ofte n “re m ote ” area of t h e h osp it al. Pre o pe rative im aging (Fig. 8.1).
•
•
Preprocedure Considerations General • At ten d to th e ABCs of resu scitat ion (air w ay, breath ing, •
• •
circulat ion ). Con t rol brisk bleeding from th e scalp an d associated w oun ds w ith h em ost at s or tem porar y st aple closure, as w ell as a pressu re dressing. Large, isolated scalp w ou n d s m ay lead to fat al blood loss. Docu m en t en t ran ce an d exit (if p resen t) w ou n ds, as w ell as th e presen ce of pow der burn s, CSF leak, an d brain h ern iat ion . Early invasive ICP m on itoring is an opt ion w h en un able to follow a serial n eurologic exam , w h en th e n eed to evacu ate an obser ved m ass lesion is u n cert ain , an d/or w h en im aging suggest s in creased in t racran ial p ressu re.9 Brain t issu e oxygen m on itoring m ay be con sidered as w ell.
Radiographic Imaging • Anteroposterior and lateral skull X-rays m ay provide general inform ation regarding the presence of radiopaque foreign bodies as well as entrance and exit sites. The ease w ith w hich m ultiplanar CT can be obtained in m ost settings has largely obviated the need for this diagnostic m odalit y.
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•
Medication • An t im icrobial prophylaxis is adm in istered. Broad-spect rum • • •
coverage, perh aps skew ed tow ard skin ora, is appropriate in th e set t ing of gross con t am in at ion of th e w ou n d. An t iepilept ic drug prophyla xis is in it iated. A loading dose of m an n itol 20% (1 g/kg) m ay be given . A t ype an d cross-m atch sh ou ld be perform ed. Coagulopathy often develops in th e set t ing of pen et rat ing injur y due to in creased t issue th rom boplast in act ivit y. En sure availabilit y of a range of blood p rodu cts (red blood cells, fresh frozen plasm a, an d p latelets), as w ell as adju n ct ive agen ts (aprot in in , desm opressin , recom bin an t factor VII, t ran exam ic acid, vit am in K, an d p roth rom bin com p lex con cen t rates) th at m igh t becom e n ecessar y p erioperat ively.
Operative Field Preparation • If vascu lar inju r y is su sp ected, en su re th at app rop riate su p p lies (m icroscop e, an eu r ysm clip s, m icrosu rgical in st ru m en t s, blood produ cts) are available prior to skin in cision .
8 Surgical Debridem ent of Penetrating Injuries
a
b
Fig. 8.1a–c Axial CT (a) brain and (b) bone windows demonstrating a comminuted bilateral frontal bone fracture, associated with a large left frontal intraparenchymal hematoma, in-driven bone, and pneum ocephalus. (c) Three-dimensional reconstructed image demonstrates the full extent of the bony injury; note that the missile is actually lodged in the extracranial space, just posterior and lateral to the depressed fracture.
c
• Con t rol bleeding from scalp an d associated w oun ds. Tem -
• Th e surgical site is prepared w ith alcoh ol, follow ed by a
p orar y st aple or su t ure closure m ay be n ecessar y to perm it p reparat ion of th e eld. Foreign bod ies prot ruding from th e h ead are left in place d uring prep arat ion of th e su rgical site. A w ide area of scalp is sh aved to ensure iden t i cat ion of en t ran ce an d exit sites, to clear su p er cial scalp d ebris, an d to allow for a large cran ial open ing.
p ovidon e-iodin e or ch lorh exidin e solu t ion in th e usu al sterile fash ion . Avoid th e lat ter if exp osed brain is presen t . A dilu ted p ovidon e-iodin e solut ion m ay be u sed for th e preparat ion of large con t am in ated w ou n ds. Th e in cision is m arked an d in lt rated w it h 1% lid ocain e w it h 1:100,000 ep in ep h r in e. Avoid areas of exp osed brain t issu e.
• •
•
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Operative Procedure Positioning (Fig. 8.2)
Figure
Procedural Steps
Pearls
Fig. 8.2
The patient position w ill be dictated by the localization of the pathology. A donut or horseshoe head holder is used to expedite the procedure.
• If the cervical spine has not been cleared,
If a unilateral procedure is planned, the patient is positioned supine, w ith the head turned contralateral to the side of the approach. A shoulder roll is placed longitudinally beneath the ipsilateral shoulder. If a bilateral procedure is planned, the patient’s head is positioned in a neutral, upright position. The back of the bed is raised slightly.
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the cervical collar should be m aintained and the patient rotated in-line to expose the side of the approach.
8 Surgical Debridem ent of Penetrating Injuries
Incision Planning (Fig. 8.3)
Figure
Procedural Steps
Pearls
Fig. 8.3
A reverse question mark–type incision is traced on the scalp for a unilateral approach. A bicoronal incision—positioned posterior to the hairline—is marked for a bilateral procedure.
• Avoid incorporating the entrance/exit
A no. 10 blade is used to incise the skin along the previously marked line. The incision is carried dow n to the level of pericranium superiorly and temporalis fascia inferiorly. Scalp clips are applied to the skin edges to facilitate hemostasis.
wound into the incision, given the high likelihood of devitalized local soft tissue. By the sam e token, be sensitive to the position of the wound(s) with respect to the planned incision and scalp blood supply.
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Subcutaneous Dissection (Fig. 8.4)
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Figure
Procedural Steps
Pearls
Fig. 8.4
The pericranium is opened w ith monopolar electrocautery, in-line w ith the scalp incision. The temporalis fascia and muscle are also opened w ith monopolar electrocautery. The resultant myocutaneous ap is re ected forw ard until the keyhole and root of zygoma are visible. The ap is secured w ith the surgeon’s retraction system of choice.
• Dissection of soft tissue away from areas of
•
known bony defect (i.e., entrance and exit sites) should be accomplished with a periosteal elevator rather than electrocautery. In the set ting of a bicoronal approach, the pericranium may be elevated in a separate layer to provide vascularized grafting material later in the procedure.
8 Surgical Debridem ent of Penetrating Injuries
Bur Hole Placement (Fig. 8.5)
Figure
Procedural Steps
Pearls
Fig. 8.5
For a unilateral approach, bur holes are placed at the key hole, just above the root of zygoma, over the parietal eminence, and at a point that is just anterior to coronal suture and 1 cm lateral to midline.
• If substantial bony injury is present, it
For a bilateral approach, bur holes are placed bilaterally at the keyhole ; just above the root of zygoma; at the junction of superior temporal line and coronal suture ; and at one or tw o points straddling the midline, anterior to coronal suture.
• Bone w ax is applied to the bony edges. A no. 3 Pen eld is used to strip the dural attachments from the undersurface of the calvarium betw een each set of holes.
m ay be feasible to rem ove portions of the involved calvarium without the use of power tools. In such cases, bur holes should be positioned to facilitate creation of a bone ap that allows access to adequate surface area to perm it control of vascular structures, judicious debridem ent, and dural closure. Take particular care when adequate access requires crossing the m idline. If the path is not readily cleared, rem em ber that bur holes are cheap relative to a sinus injury.
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Craniotomy (Fig. 8.6)
Figure
Procedural Steps
Pearls
Fig. 8.6
The craniotome is used to create a path that circumnavigates the previously placed bur holes.The resulting bone ap is carefully elevated aw ay from the underlying dura and set aside in antibiotic solution.
• Direct visualization of the dural
For a bilateral approach, it may be easier to create tw o separate unilateral aps, temporarily leaving a strip of bone along the midline. Craniotome cuts then can be made across the midline and the bony isthmus removed. Venous sinus bleeding is controlled w ith a combination of gentle pressure and hemostatic agents. Epidural hematoma, if present, may be evacuated at this time.
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•
surface during elevation of the bone ap is key, as the craniotomy site likely includes an area of known bony and dural defect. If direct injury to the sinus is suspected, it may be necessary to proceed with repair and/or ligation (anterior one-third only). Preoperative imaging should prompt appropriate forethought and preparation.
8 Surgical Debridem ent of Penetrating Injuries
Dural Opening (Fig. 8.7)
Figure
Procedural Steps
Fig. 8.7
By de nition, the dura is already “open.” In certain cases, it may be appropriate simply to enlarge the existing dural opening to permit the necessary exposure for local debridement. If a need for broad exposure is anticipated, a cruciate or reverse C-shaped dural opening should be considered. In the setting of a bicoronal approach, trap-door dural aps can be re ected tow ard the midline sagittal sinus.
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Approach to Parenchymal Injury (Fig. 8.8a, b)
a
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8 Surgical Debridem ent of Penetrating Injuries
b
Figure
Procedural Steps
Pearls
Fig. 8.8
Subdural hematoma, if present, should be evacuated w ith a combination of gentle suction and saline irrigation. (a) Inspect the cortical surface. Address obvious points of arterial or venous bleeding. There is likely obvious cortical disruption. This should be the portal of entry for debridement. Associated large intraparenchymal hematoma should be approached w ith a combination of gentle suction and bipolar electrocautery. Upon entry to the hematoma cavity, suction out any liquid clot. Remove solid clot in a piecemeal fashion. (b) If no signi cant hematoma is present, super cial, necrotic brain tissue should be debrided w ith gentle suction and irrigation. Readily accessible missile and bone fragments should be retrieved. Continue until gliotic brain is visible on all sides. Hemostasis should be achieved w ith a combination of bipolar electrocautery and hemostatic agents.
• Principles of debridem ent for penetrating injuries
• • •
encom pass techniques previously discussed for evacuation of subdural hem atom a (Chapter 1) and cerebral contusions (Chapter 3). Managem ent of venous sinus injury is discussed in Chapter 10. Techniques for frontal sinus reconstruction are discussed in Chapter 27. Please refer to these sections for m ore detailed nuances of m anagem ent. A hand-held m alleable retractor, introduced over a saline-m oistened 1 3 3 cm cot ton pat tie m ay assist visualization. No at tempt should be made to follow m issile trajectory to deep subcortical structures. Always maintain awareness of position relative to the lateral ventricles. Avoid entry to the ventricle, if feasible.
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Duraplasty (Fig. 8.9)
Figure
Procedural Steps
Pearls
Fig. 8.9
Once debridement of devitalized brain tissue is complete, assess the extent of the dural defect.
• It is important to determ ine the relationship •
For a unilateral approach, a piece of pericranium may be harvested to bridge the defect. The graft is incorporated circumferentially w ith 4-0 braided nylon sutures. For a bicoronal approach, the previously harvested vascularized pericranial graft may be apped over the exenterated frontal sinus and secured w ith 4-0 braided nylon suture, augmented by brin glue.
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of the defect to adjacent air sinuses. If no viable pericranium is available, temporalis fascia, fascia lata, or synthetic dural substitute may be prepared for this purpose.
8 Surgical Debridem ent of Penetrating Injuries
Closing • Th e surgical site is irrigated w ith an t ibiot ic solu t ion . • Th e decision of w h eth er to replace th e bon e ap at th e con -
•
• • • •
clusion of th e procedure is based both on th e degree of brain sw elling p resen t an d w h eth er th e bon e ap can be salvaged . In som e cases, th e bon e ap is too com m in u ted or too grossly con t am in ated to perm it re-im plan t at ion . Th e soft t issue elem en t s (m uscle an d scalp) m ust be in spected at sites of en t r y an d exit . Sh arp local debridem en t back to viable t issu e m ay be n ecessar y. Irrigate w ith cop iou s am ou n t s of an t ibiot ic solut ion prior to single-layer reapproxim at ion w ith 3-0 nylon in terrupted st itch es. Th e part icipat ion of a p last ic surger y colleagu e m ay be ap prop riate if exten sive soft t issue injur y is presen t an d ch allenges to ach ieving su cien t su rface area coverage are an t icipated . A Jackson -Prat t drain is laid in th e subgaleal space prior to closure. Th e tem poralis m uscle an d fascia are re-approxim ated w ith 0 braided absorbable sut ures. Th e galea an d su bcut an eou s t issue are reapproxim ated w ith 2-0 braided absorbable sut ures. Th e skin is closed w ith st aples. A run n ing-locking 3-0 nylon st itch m ay assist h em ostasis if coagu lop athy is presen t or bolster th e closu re if su bst an t ial sw elling is p resen t .
•
Medication • Th e opt im al prophylact ic an t im icrobial regim en an d durat ion
•
• Im m ediate p ostop erat ive CT allow s for assessm en t of residu al
•
Postoperative Management Monitoring •
•
t ing follow ing operat ive in ter ven t ion . Th e use of invasive n eurologic m on itors (in t raparen chym al or in t raven t ricu lar) is appropriate for pat ien ts in w h om serial n eu rologic exam is n ot feasible an d/or w h ose GCS rem ain s 8. Th e out put of subgaleal an d/or su bdural drains—if presen t— sh ou ld be m on itored . Drain rem oval m ay be con sidered w h en
of th erapy rem ain a m at ter of debate. Th ere is th e suggest ion th at broad-spect ru m coverage sh ould probably con t in ue for a p eriod th at is som ew h at longer th an stan dard prop hylaxis for a clean , elect ive p rocedu re. Th e au th ors con t in u e broadsp ect ru m coverage for 3 to 5 days p ost-inju r y.9 An t iepilept ic drug prophylaxis is con t in ued for a tot al of 7 days post-injur y.
Radiographic Imaging
•
• Pat ien t s sh ou ld be m on itored in th e in ten sive care u n it set-
out put s becom e m in im al an d/or serial im aging dem on st rates resolu t ion of th e t argeted collect ion . Mon itor for clin ical eviden ce of CSF otorrh ea or rh in orrh ea.
•
or n ew h em atom a, exten t of foreign body debridem en t , an d edem a pat tern . On ce st abilit y of any evolving h em atom a h as been establish ed, CT im aging sh ould be repeated on ly for sign i can t ch anges in n eu rologic st at u s. Th e persisten ce or delayed developm en t of pn eum oceph alus beyond th e im m ediate postoperat ive period—in th e absen ce of an overt CSF leak—sh ould prom pt a search for an occult p oin t of egress. Th e presen ce of n ew su barach n oid h em orrh age or h em atom a in th e area of a n am ed vessel sh ou ld prom pt vascu lar im aging. Likew ise, repeat vascular im aging at an in ter val of several days is appropriate for any pat ien t w h o un der w en t such im aging at p resen tat ion —w ith a n egat ive resu lt—on th e basis of su sp iciou s CT n d ings. Po sto perative im aging (Fig. 8.10).
Further Management • Invasive n eu rom on itoring devices are rem oved w h en n eu ro•
logic st at u s dictates. Skin su t u res or staples are rem oved at an in ter val of 10 to 14 days.
c a b Fig. 8.10a–c Axial CT (a) brain and (b) bone windows demonstrating evacuation of the frontal hematoma and accessible foreign body fragment s. A bony defect remains. (c) CT obtained approximately 3 months later (at the tim e of cranioplast y) demonstrates expected frontal encephalomalacia.
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I Cerebral Traum a and Stroke
Special Considerations • CSF leak ◦ The inciden ce of CSF leak follow ing m issile injury approached
•
132
28%in one large series.13 ◦ Th is com p licat ion resu lts from direct violat ion of th e dura—by project ile or bony fragm en t s—along w ith failure to seal th e defect by n orm al t issu e h ealing p rocesses. ◦ CSF drain age occu rs along th e p ath of least resist an ce— from en t ran ce or exit w ou n ds or from th e ear or n ose in th e set t ing of air sin us violat ion . ◦ Th e m ost feared com p licat ion of CSF leak is in fect ion — m en ingit is an d /or abscess.1,12,14 ◦ Ever y e ort sh ou ld be m ade to at t ain a w ater-t igh t closu re of th e du ra at th e t im e of in it ial su rgical debridem en t .1,9 Prim ar y su t ure closure m ay be feasible. Som et im es, augm en t at ion w ith a p ericran ial graft or syn th et ic m aterial is n ecessar y. In oth er cases, th e leak occu rs along th e sku ll base, w h ere “closure” is n ot n ecessarily feasible. A m ult ilayer w ou n d closu re w ill bolster th e repair. ◦ CSF leak m ay be a d elayed p h en om en on . In it ial brain sw elling m ay t am p on ade a site of poten t ial egress. Th e leak m ay on ly becom e eviden t as sw elling subsides several days after th e injur y. ◦ If a CSF leak develop s, in it ial m an agem en t m ay con sist of tem porar y diversion via ven t ricu lostom y or lum bar drain (if n ot con t rain dicated). Th e h ead of th e bed sh ou ld be elevated . Many leaks w ill resolve sp on tan eou sly w ith con servat ive m easu res. If th e leak is refractor y to CSF diversion , su rgical repair is recom m en ded.9 ◦ If th e p oin t of egress is n ot obviou s by im aging, a CT sin u s m et rizam ide st u dy m ay assist localizat ion . Low -dose in t rath ecal uorescein (less th an or equ al to 50 m g) m ay provide an adju n ct at th e t im e of en doscopic exp lorat ion . In fect iou s com plicat ion s ◦ Th e rate of in fect ion follow ing pen et rat ing brain inju r y is low er in th e civilian th an m ilitar y popu lat ion an d appears to var y directly w ith th e u se of broad-sp ect ru m an t ibiot ics in th e early m an agem en t of th ese pat ien ts.9 ◦ Risk factors for in fect ion in clu de CSF leak, w ou n d deh iscen ce, violat ion of an air sin us, t ran sven t ricular t rajector y, an d/or inju r y crossing m idlin e.15 Ret ain ed m issile an d bon e fragm en ts dem on st rate a less con clu sive relat ion sh ip to th e developm en t of in fect ion . ◦ Most in fect ion s occu r relat ively early in th e post-inju r y period. In on e st udy, 55% occurred w ith in 3 w eeks an d 90% w ith 6 w eeks; rarely, a delay in on set of several years m ay be obser ved.16 ◦ Th ere exist s great variabilit y in pract ice arou n d th e issu e of an t im icrobial prophylaxis in th e set t ing of pen et rat ing inju r y. Th e cu rren t Pen et rat ing Brain Inju r y guidelin es m ake th e argu m en t th at if exten sive Class I an d Class II dat a suppor t th e use of prophylaxis in th e set t ing of clean procedures, it w ould be reason able to provide broader coverage of longer du rat ion in th e set t ing of a kn ow n open , con tam in ated w oun d. How ever, n o dat a con clusively su p port a speci c regim en or durat ion .9 ◦ Staphylococcus is isolated m ost com m only; however, a w ide range of gram -negative and anaerobic organism s have also
been im plicated as causative agents—bolstering the argum ent for broad-spectrum coverage at the outset. Once an infectious process has been identi ed, antibiotic therapy m ust be tailored to culture and susceptibilit y data. Surgical debridem ent m ay be indicated in the setting of brain abscess or em pyem a. Please see Chapter 20 for further discussion regarding the surgical m anagem ent of intracranial infection.
References 1. Aarabi B. Cau ses of in fect ion s in pen et rat ing h ead w ou n d s in th e Iran -Iraq War. Neurosurger y 1989;25:923–926 2. Am irjam sh idi A. Min im al debrid em en t or sim p le w ou n d closu re as th e on ly su rgical t reat m en t in w ar vict im s w ith low -velocit y pen et rat ing h ead inju ries. In dicat ion s an d m an agem en t p rotocol based upon m ore th an 8 years follow up of 99 cases from Iran -Iraq con ict . Surg Neurol 2003;60:105–111 3. Tah a JM, Haddad FS, Brow n JA. In t racran ial in fect ion after m issile injuries to th e brain : repor t of 30 cases from th e Lebanese con ict . Neurosurger y 1991;29:864–868 4. Ch au dh ri KA, Ch ou dh u r y AR, al Mou t aer y KR, et al. Pen et rating cran iocerebral sh rap n el inju ries during “Operat ion Desert Storm :” early resu lt s of a con ser vat ive su rgical t reat m en t . Act a Neuroch ir (Wien ) 1994;126:120–123 5. Esp osito DP, Walker JB. Con tem p orar y m an agem en t of p en et rating brain injur y. Neurosurg Q 2009;19(4):249–254 6. Mu en ch E, Horn P, Bau h u f C, et al. E ect s of hyp er volem ia an d hyperten sion on region al cerebral blood ow, in t racran ial pressure, an d brain t issue oxygen at ion after subarach n oid h em orrhage. Crit ical Care Med 2007;35:1844–1851 7. Bran dvold B, Levi L, Fein sod M, et al. Pen et rat ing cran iocerebral injuries in th e Israeli involvem en t in the Leban ese con ict . J Neurosurg 1990;72:15–21 8. George ED, Diet ze JB. Pat ien t select ion : determ in ing th e n eed for and t ype of su rger y. In : Bizh an A, ed. Missile Woun ds of th e Head an d Neck. Neurosurgical Topics Volum e I. New York: AANS; 1999:127–134 9. Aarabi B, Alden TD, Ch est n u t RM, et al. Gu idelin es for th e m an agem en t of pen et rat ing brain injur y. J Traum a 2001; 51(supplem en t):S1–86 10. Helling TS, McNabn ey W K, W h it t aker CK, et al. Th e role of early surgical in ter ven t ion in civilian gun sh ot w oun ds to th e h ead. J Traum a 1992;32:398–400 11. Hu bsch m an n O, Sh ap iro K, Bad en M, et al. Cran iocerebral gu n sh ot injuries in civilian pract ice: progn ost ic criteria an d surgical m an agem en t experien ce w ith 82 cases. J Traum a 1979;19:6–12 12. Gon u l E, Baysefer A, Kah ram an S. Cau ses of in fect ion s an d m an agem en t resu lt s in p en et rat ing cran iocerebral inju ries. Neu rosurg Rev 1997;20:177–181 13. Aren dall RE, Mein ow sky AM. Air sin u s w ou n d s: an an alysis of 163 con secut ive cases in curred in the Korean War, 1950-1952. Neurosu rger y 1983;13:377–380 14. Meirow sky AM, Caven ess W F, Dillon JD, et al. Cerebrospin al u id st ulas com plicat ing m issile w oun ds of th e brain . J Neurosurg 1981;54:44–48 15. Aarabi B, Tagh ipou r M, Alibaii E, Kam garp ou r A. Cen t ral n er vou s system in fect ion s after m ilit ar y m issile h ead w oun ds. Neu rosurger y 1998;42:500–509 16. Tah a JM, Saba MI, Brow n JA. Missile inju ries to th e brain t reated by sim ple w oun d closure: result s of a protocol during th e Lebanese con ict . Neurosurger y 1991;29:380–383
9
Management of Traumatic Neurovascular Injuries Boyd F. Richards and Mark R. Harrigan
◦ Sp eci c segm en t s of th e carot id an d ver tebral ar teries are
Introduction All t rau m at ic cerebrovascu lar inju r ies (TCVI) involve eit h er p ar t ial or com p lete d isr u pt ion of t h e vessel w all. Trau m at ic ar ter ial cerebrovascu lar inju r ies con st it u te a con t in u ou s sp ect r u m of d isease, ran gin g from m in im al d isr u pt ion of t h e in t im a to occlu sion or t ran sect ion of t h e ar ter y. TCVI can also lead to t h e for m at ion of ar ter ioven ou s st u las an d an eu r ysm s. Th ese inju r ies can be classi ed accord in g to locat ion (ext racran ial or in t racran ial) an d by m ech an ism (blu n t or p en et rat in g). Th is ch ap t e r is d ivid e d in t o fou r cat e gor ies b ase d on locat ion an d m e ch an ism . Th e a u t h ors p rese n t a lgor it h m s b ase d on ou r p refe r re d t reat m e n t st rat e gy for m ost ca ses at ou r in st it u t ion .
•
Indications Extracranial Blunt Injury • TCVI occu rs in abou t 1%of all blu n t t rau m a pat ien t s.1 Carot id • •
• •
inju r y occurs in 0.1 to 1.55% of blun t t raum a pat ien t s. Vertebral injur y occurs in 0.2 to 0.77% of t raum a pat ien t s. Motor veh icle collision s accou n t for 41 to 70%of cases.2 Oth er m ech an ism s of inju r y in clu de assau lt , p ed est rian versu s veh icle, an d h anging. Th e inju r y m ay result from a direct vascular blow, ext rem e hyperexten sion /rotat ion , or lacerat ion by bony fragm en ts. ◦ In depen den t risk factors for carot id ar ter y inju r y in clu d e: closed h ead inju r y (w ith Glasgow Com a Scale [GCS] score 6), pet rou s bon e fract u re, d i u se axon al inju r y, an d LeFor t II or III fract u re. ◦ Cer vical spin e injur y—C1, 2, or 3 fract u re; t ran sverse foram en fract u re; or su blu xat ion —is an in dep en d en t risk factor for vertebral ar ter y inju r y. Th e m ost com m on ly used classi cat ion system divides TCVI in to ve t yp es (Table 9.1).3,4 Ar t er ia l dissect ion (t ype I a n d II in ju r ies) ◦ Results from rapid decelerat ion of th e body w ith subsequen t st retch ing of th e involved vessel. ◦ Tw o m ech an ism s h ave been proposed (Figs. 9.1 an d 9.2): (1) in t ram ural h em atom a form at ion bet w een layers of th e arter y w all; an d (2) an in t im al tear leading to exposed su ben d oth elial collagen , in it iat ing p latelet aggregat ion an d leading to th rom bus form at ion .
•
m ore vu ln erable to dissect ion th an oth ers: ▪ Carot id : th e dist al cer vical in tern al carot id ar ter y (ICA), w h ere th e ICA is st retch ed over th e lateral m asses of th e cer vical spin e, is at risk. Injur y t ypically result s from hyperexten sion an d rotat ion to th e con t ralateral side. ▪ Ver tebral: th e V2 an d V3 segm en t s, as th e vessel t ravels th rough th e t ran sverse foram in a of C6 to C2 an d arou n d th e lateral m ass of C1, are at risk. V2 segm en t injuries t yp ically h ave an associated cer vical spin e injur y, w h ereas inju r y to V3 or V4 segm en t s m ay occu r in isolat ion . Tr a u m a t ic a n eu r ysm (t ype III in ju r ies) ◦ Th is results from disrupt ion of th e in tern al elast ic lam in a, w h ich w eakens th e vessel w all an d leads to expan sion of th e adven t it ia. ◦ Th e term pseudoaneurysm im plies a com plete disrupt ion of all layers. How ever, dissect ing an eur ysm s m ay con t ain a com p lete ar ter y w all. So, th e term t raum at ic aneurysm is m ore app ropriate. ◦ Traum at ic an eu r ysm s of th e carot id arter y t ypically occu r in th e m id- or u pp er cer vical ICA an d accoun t for 15 to 44% of TCVIs. A port ion (7.6%) of carot id injuries th at in it ially con sist on ly of lum in al irregu larit y later develop in to t rau m at ic an eu r ysm s.5 ◦ Traum at ic an eur ysm accoun t s for on ly 4.8%of vertebral arter y TCVIs. ◦ Un like spon tan eous dissect ing an eur ysm s, t raum at ic an eu r ysm s ten d to persist an d often en large over t im e.6 Occlu sion (t ype IV in ju r ies) ◦ Traum at ic vascular occlu sion m ay occur at th e t im e of th e inju r y or m ay arise in a delayed fash ion as th e resu lt of th rom bu s form at ion at th e site of an arterial dissect ion .
Table 9.1 Classi cation of blunt traumatic cerebrovascular injury Type
Description
I
Lum inal irregularit y or dissection; , 25% stenosis
II
Raised intim al ap or dissection; . 25% stenosis
III
Traum atic aneurysm
IV
Complete occlusion
V
Transection and/or development of arteriovenous stula
Source: Bi WL, Moore EE, O ner PJ, et al. Blunt carotid arterial injuries: implications of a new grading scale. J Trauma 1999;47(5):845–853; Bi WL, Moore EE, Elliot t JP, et al. The devastating potential of blunt vertebral arterial injuries. Ann Surg 2000;231(5):672–681.
133
I Cerebral Traum a and Stroke • Carot id ar ter y inju r y d u e to p en et rat in g n eck t rau m a re -
•
•
Physical Findings Physical ndings of penetrating, extracranial cerebrovascular injury ◦ Act ive bleeding ◦ Hem atom a ◦ Th rill or bruit ◦ Absen ce of carot id pulse ◦ Neu rologic de cit
Fig 9.1 Type I traumatic cerebrovascular injury. A mid-cervical internal carotid artery intramural hematoma (arrow) causing , 25% reduction in luminal diameter.
◦ Occlu sion is m u ch less com m on th an ar terial dissect ion . ◦ Pat ien t s m ay p resen t w it h sym ptom s of isch em ic st roke •
• •
or rem ain asym ptom at ic if good collateral circu lat ion exist s. Ar t er ioven ou s f st u la s (t ype V in ju r ies) ◦ Presen t w ith t inn it us, cer vical radiculopathy, h eart failure, h em orrh age, steal, in t racran ial ven ou s hyp erten sion , or em bolic st roke. Type I traum atic ce rebrovascular injury (Fig. 9.1). Type II traum atic ce rebrovascular injury (Fig. 9.2).
Intracranial Blunt Injury • Dat a regarding th e overall in ciden ce of blun t in t racran ial • •
Extracranial Penetrating Injury • Pen et rat ing n eck t rau m a is accom pan ied by vascu lar inju r y • •
134
in 20% of pat ien t s.7 Seven t y- ve p ercen t of th ese vascu lar inju ries are att ribu t able to st abbing. Gu n sh ot w ou n ds accou n t for th e rem ain d er.8 Th e ven ous system is m ore com m on ly a ected bu t less likely to requ ire t reat m en t .
su lt s in vessel occlu sion in 36% of cases an d t rau m at ic an eu r ysm for m at ion in 33% of cases.9 As com p ared w it h blu n t ext racran ial carot id inju r y, t h e rate of isch em ic st roke w it h a p en et rat in g inju r y is low er, bu t t h e m or t alit y rate is h igh er.10 Pen et rat ing ext racran ial inju ries can be classi ed by t yp e: ◦ Ar t er ia l la cer a t ion ◦ Dissect ion ◦ Occlu sion ◦ An eu r ysm ◦ Ar t er ioven ou s f st u la . Fist u las m ay be eit h er carot id -caver n ou s (d iscu ssed in t h e blu n t in t racran ial inju r y sect ion ) or ver tebral-ven ou s in n at u re. Th e lat ter m ay p resen t as t in n it u s, cer vical rad icu lop at hy, h ear t failu re, h em orrh age, steal, in t racran ial ven ou s hyp er ten sion , or em bolic st roke. Slow - ow st u las m ay be follow ed exp ect an t ly w it h ser ial angiograp hy ever y 12 m on t h s in asym ptom at ic an d ot h er w ise clin ically st able p at ien t s. High - ow st u las m ay cau se brain stem or sp in al cord sym ptom s d u e to p ressu re from ar ter ializat ion of t h e cer vical ven ou s p lexu s. Poster ior circu lat ion isch em ia m ay resu lt from d iversion of ow . Physical exam in at ion is th e m ost im p or tan t part of th e diagn ost ic evaluat ion for pen et rat ing cer vical vascular injur y (see box below ). ◦ If physical sign s of vascu lar inju r y are p resen t , th ere is a 90% ch ance of a m ajor arterial or ven ou s injur y.11 ◦ In th e absen ce of p hysical sign s, th e risk of m ajor vascu lar inju r y falls to 0.9%.11
TCVIs is lacking. Su ch inju ries are su bst an t ially less com m on th an blun t ext racran ial injuries. GCS score , 8 an d th e p resen ce of facial fract u res are in depen den t risk factors for blun t in t racran ial arterial injur y.12 Blun t in t racran ial injuries m ay be classi ed by t ype: ◦ Dissect ion ▪ May be associated w ith t rivial t rau m a or blu n t inju r y in closed h ead t raum a, as w ell as pen et rat ing injur y. ▪ Th e m ost com m on a ected sites are th e su praclin oid ICA an d th e in t radu ral p or t ion of th e ver tebral arter y. ▪ In t racran ial dissect ion m ay be associated w ith u n derlying vascu lar abn orm alit y of th e cerebral ar teries, in clu d ing broelast ic th icken ing an d congen it al de cien cy w ith disrupt ion of th e in tern al elast ic lam in a. Associated con dit ion s th at m ay predispose on e to dissect ion in th e
9
Managem ent of Traum atic Neurovascular Injuries
a
b
Fig. 9.2a, b Type II traumatic cerebrovascular injury, t wo examples: (a) focal dissection, likely an intimal ap, with thrombus (arrow) and (b) di use injury, likely an intramural hem atoma (arrows).
set t ing of blu n t inju r y in clu de brom u scu lar hyp erp lasia, cyst ic m edial degen erat ion , Marfan syn drom e, h om ocyst in u ria, an d syph ilis. ▪ Pat ien t s m ay p resen t w ith u n ilateral h eadach e, cran ial n er ve palsy (from m ech an ical com pression or n eurap raxia from th e expan ded ar ter y or t ran sien t im p airm en t of blood su pply), Horn er’s syn drom e, an d/or focal cerebral isch em ia. ◦ An eu r ysm ▪ Trau m at ic an eu r ysm s accou n t for , 1%of all in t racran ial an eu r ysm s in adu lt s, bu t com prise abou t on e-th ird of p ediat ric an eu r ysm s.13 ▪ An eur ysm s in th is set t ing result from rapid decelerat ion , w h ich cau ses sudden brain m ovem en t an d arterial w all injur y from stat ion ar y st ru ct ures su ch as th e skull base or falx cerebri. ▪ Pe r icallosal bran ch (an t e r ior com m u n icat in g ar te r y [ACA]) an e u r ysm s, resu lt in g from collision b et w e e n t h e ar t e r y an d t h e e dge of t h e falx, are m ost com m on . ▪ Basilar arter y an d pet rocavern ou s segm en t an eu r ysm s often are associated w ith skull base fract ures.
◦ Ar t er ioven ou s f st u la ▪ Ar terioven ous st ulas—arising from eith er th e carot id ▪ ▪
▪ ▪
or ver tebral circulat ion —are presen t in 4% of all pat ien t s w ith blu n t TCVI.14 Th e m ost com m on in t racran ial t raum at ic st ula is a direct carot id-cavern ous st ula (CCF). Seven t y- ve p ercen t of direct CCFs occu r secon dar y to t raum a. ▫ Most are associated w ith facial or sku ll base fract u res. ▫ Iat rogen ic injur y—due to tran ssph en oidal surger y, skull base surger y, or percutaneous lesioning of the trigem in al ganglion —also accoun ts for a signi can t n u m ber of t raum at ic st ulas. Pat ien t s t yp ically p resen t w ith cavern ou s sin u s syn drom e (see box on n ext page). In d icat ion s for u rgen t t reat m en t in clu de: ▫ In creased in t racran ial p ressu re or th e p resen ce of cerebral cort ical ven ous hyperten sion ▫ Progressive visual de cit ▫ In creased in t raocu lar p ressu re ▫ Worsen ing proptosis
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I Cerebral Traum a and Stroke Traum atic Caverno us Fistula Traum atic cavernous stula symptom s and physical ndings ◦ Pain fu l exop h th alm ia ◦ Pulsat ing conjun ct ival hyperem ia ◦ Oph th alm op legia ◦ Vascu lar m urm u r ◦ Elevated in t raocu lar pressu re ◦ Loss of vision (du e to ven ou s congest ion )
Intracranial Penetrating Injury • Pen et rat ing in t racran ial inju r y m ay resu lt in dissect ion , oc-
•
•
clusion , t raum at ic an eur ysm , or ar terioven ous st ula. All h ave been discu ssed p reviously. How ever, th e form at ion of t raum at ic in t racran ial an eur ysm s secon dar y to pen et rat ing inju r y w arran t s fur th er con siderat ion . Trau m at ic in t racran ial an eu r ysm s can result from direct in ju r y by m issile, bu llet , or bon e fragm en t s. An eu r ysm s are presen t in : ◦ 2.7% of pat ien ts w ith m issile inju ries to th e h ead.16 ◦ 12% of pat ien t s w ith st ab w oun ds to th e h ead.17 An eu r ysm s m ay ap pear as soon as 2 h ou rs after th e inju r y an d are m ost com m on ly fou n d along bran ch es of th e m iddle
a
b
•
•
cerebral ar ter y (MCA) (as opposed to in t racran ial an eur ysm s due to blun t t raum a, w h ich are m ost often iden t i ed on bran ch es of th e ACA). Factors th at sh ould raise suspicion for a t raum at ic an eur ysm in clude: ◦ Missile or bon e fragm en ts close to th e sku ll base ◦ Large h em atom a at th e m issile en t ran ce w ou n d Th ough an eur ysm s occurring secon dar y to t rau m a are believed to carr y a h igh risk of rupt ure, on e st udy foun d th at 19.4% of th ese lesion s h ealed spon t an eously an d sh ran k or disappeared altogether on subsequen t angiogram s.18
Preprocedure Considerations Radiographic Imaging Extracranial Blunt Injury • A screening com puted tom ography angiogram (CTA) or m agnetic resonance angiogram (MRA) should be perform ed for any patient w ith risk factors for TCVI and/or any unexplained neurologic de cit (Fig. 9.3). In the setting of TCVI, CTA m ay reveal: ◦ Eccen t ric vessel lum en com bin ed w ith m ural th icken ing ◦ Sten osis
c
d
Fig. 9.3a–d Patterns of injury in blunt, extracranial traumatic cerebrovascular injury. Common t ypes of injury include: (a) intimal tear, (b) intimal tear with associated thrombosis, (c) dissecting aneurysm formation due to disruption of the internal elastic lamina and bulging of the adventitia, and (d) intramural hematoma.
136
9 ◦ Occlu sion ◦ Dissect ing an eu r ysm ◦ Mu ral th icken ing
• MRI an d MRA are u sefu l in cases of a w ooden foreign body •
• Cerebral angiography is in dicated w h en n ecessar y for claricat ion of th e diagn osis or w h en en dovascu lar t reat m en t is p lan n ed . In th e set t ing of TCVI, angiograp hy m ay reveal: ◦ Eccen t ric, sm ooth , or t apered sten osis ◦ In t im al ap an d associated false lu m en ◦ Tapered sten osis proxim al to a dissect ing an eur ysm (“st ring an d p earl” sign ) ◦ Flam e-sh ap ed occlu sion ◦ Dissect ing an eu r ysm ◦ In t ralu m in al th rom bu s
Extracranial Penetrating Injury • CTA or MRA is th e rst-lin e im aging m odalit y at our in stit ution . • Angiograp hy is reser ved for cases in w h ich t h e CTA re•
Extracranial Blunt Injury (Fig. 9.4) • Th e corn erston es of m an agem en t for ext racran ial blun t
•
Intracranial Blunt Injury • Dissect ion ◦ All pat ien t s suspected of h aving an in t racran ial dissect ion
•
•
Intracranial Penetrating Injury • A screen ing CTA or MRA (un less con t rain dicated) sh ould be •
p erform ed for any pat ien t presen t ing w ith p en et rat ing h ead inju r y. Met allic foreign bodies m ay com p rom ise CT im ages secon dar y to scat ter art ifact . Th ey m ay also ren der an MRA im p ossible. In th is case, an angiogram m ay be n ecessar y p rior to rem oval of th e foreign object .
injur y, as it is di cult to visualize w ooden m aterial on a CT. Repeat , delayed angiography sh ould be perform ed 3 to 6 m on th s later for pat ien t s in w h om an arterioven ous st u la is suspected.
Management
su lt s are equ ivocal or w h en en d ovascu lar t reat m en t is an t icip ated . Angiography is also in dicated if th ere is a retain ed m et allic foreign object th at m igh t obscu re in terp retat ion of CTA or MRA du e to art ifact .
sh ou ld u n d ergo a CTA or MRA as a rst-lin e im aging m odalit y. How ever, if a dissect ion is st rongly suspected, con ven t ion al angiography rem ain s th e gold st an dard. An eu r ysm ◦ CTA is th e recom m en ded screen ing m odalit y. How ever, t raum at ic an eur ysm s are often located dist ally an d can be dangerous even w h en , 3 m m . Th ese t w o feat ures ren der CTA less reliable. ◦ Angiography is recom m en ded for all pat ien t s in w h om a t raum at ic an eur ysm is suspected. Ar t er ioven ou s f st u la ◦ Angiography is th e gold st an dard to im age ar terioven ous st u las. ▪ An early- lling vein m ay be a path ogn om on ic sign . ▪ Assess for access to th e lesion by looking at th e direct ion of ow w ith in each of th e ven ou s st ruct ures. ▪ For CCFs, assess th e presen ce of th e superior op h th alm ic vein as a possible access p oin t for t reat m en t . ◦ CTA an d MRA are st at ic st u dies. Early ven ou s lling often is n ot visu alized as th e t im ing of th e con t rast bolu s m ay a ect t im ing of th e lling of th e vein s.
Managem ent of Traum atic Neurovascular Injuries
•
TCVI are an t ith rom bot ic th erapy (to m in im ize th rom boem bolic com plicat ion s), follow -up im aging, an d select ive use of en dovascu lar tech n iqu es. Medica l m a n a gem en t ◦ Anticoagulation w ith intravenous heparin, followed by warfarin, has been com m on practice. However, hem orrhagic com plication rates range from 8 to 16%19 and a signi cant proportion (30–36%) of patients w ith this type of injury are not candidates for system ic anticoagulation due to concom itant injuries. ◦ An t iplatelet th erapy o ers a m ore favorable risk pro le an d m ay be equ ivalen t to or su p erior to an t icoagu lat ion w ith respect to n eu rologic outcom es.20 Th e au th ors p refer single agen t an t iplatelet th erapy in th e form of aspirin 325 m g per day. ◦ Repeat n on invasive im aging, preferably CTA, sh ou ld be u n der t aken in 6 m on th s. En dova scu la r m a n a gem en t ◦ Dissect ion ▪ Dissect ion s requ ire t reat m en t (u su ally sten t ing) if th ere are n ew n eu rologic de cits or oth er sym ptom s desp ite an t iplatelet th erapy. ▪ Sten t ing requires dual an t iplatelet th erapy for a period of app roxim ately 1 m on th ; th is m ay p rove p roblem at ic for p olyt rau m a pat ien ts. ◦ Trau m at ic an eur ysm ▪ En dovascular t reat m en t is in dicated if th e pat ien t is sym ptom at ic despite an t ip latelet th erapy or if th e an eu r ysm is fou n d to en large sign i can tly on follow -u p im aging. Follow -u p im aging sh ould be perform ed after 6 m on th s (see Fig. 9.5). ▪ A covered sten t m ay be appropriate if th e t raum at ic an eu r ysm occu rs in a port ion of th e vessel devoid of im port an t bran ch es. ▪ Coil em bolizat ion of t raum at ic an eur ysm s sh ould be avoided w h en ever possible as th e w all of th e an eu r ysm m aybe eith er ext rem ely fragile or con sist en t irely of th rom bo- brous t issue. Coils w ith in t raum at ic an eu r ysm s m ay be pron e to m igrate th rough th e w all of th e an eu r ysm . ◦ Occlu sion ▪ Vessel occlu sion sh ou ld b e ap p roach e d in a sim ilar m an n e r to acu t e isch e m ic st roke. Sym p tom at ic ar t e r ial occlu sion s sh ou ld u n d e rgo re can alizat ion w h e n feasible an d ap p rop r iate. Pat ie n t s w it h asym p tom at ic occlu sion s m ay d o w ell w it h con se r vat ive m an age m e n t (se e Fig. 9.6).
137
I Cerebral Traum a and Stroke Su spected blu n t ext racran ial TCVI CTA
Eviden ce of vascular inju r y
Dissect ion
Traum at ic An eu r ysm
An t ip latelet Agen t
An t ip latelet Agen t
No evid en ce of vascu lar inju r y Un explain ed n eu rologic deficit or h igh susp icion
Occlu sion
Asym ptom at ic
Sym ptom at ic DSA
Neu rologic obser vat ion an d repeat CTA in 6 m on th s New n eu rologic deficit
If stable con t in u e an t iplatelet agen t
Neu rologic obser vat ion an d repeat CTA in 6 m on th s If en larging or n ew n eu rologic deficit
If resolved, d/c an t iplatelet agen t
Con sider en dovascu lar t reat m en t
DSA
If un ch anged, con t in u e an t iplatelet agen t
An t ip latelet Agen t
If resolved, d/c ant ip latelet agen t
New Trau m at ic An eu r ysm
Neurologic obser vat ion an d repeat CTA in 6 m on th s
8 h ou rs CT Perfusion At tem pt recan alizat ion if CT Perfusion sh ow s reversible isch em ia Su p p ort ive care n o reversible isch em ia
Fig. 9.4 Algorithm for the management of blunt, extracranial traumatic cerebrovascular injury. DSA, digital subtraction angiography; CTA, CT angiography; d/c, discontinue.
▪ Reperfu sion tech n iques, in cluding m ech an ical th rom -
▪
bectom y an d at tem pted recan alizat ion , sh ould be con sidered if th e t im e from sym ptom on set is less th an 8 h ou rs an d n on invasive im aging m odalit ies (such as CT perfusion or MR perfusion ) suggest a reversible isch em ic pen um bra. Reperfusion tech n iques in such cases m ay in clude em ergen t sten t placem en t or th rom bectom y. Sten t ing in th e acute set t ing requires loading w ith t w o an t iplatelet agen t s (e.g., aspirin an d clopidogrel) at least 3 h ours prior to th e procedure. An altern at ive w ould be to t reat th e pat ien t w ith an in t raven ous GPIIB/IIIA in h ibitor—to perm it sten t ing im m ediately—an d p roceed w ith an t iplatelet agen t loading later. Th e use of th ese agen ts in any pat ien t w ith polyt rau m a sh ou ld be con sid ered carefu lly becau se of bleeding risks an d th e p oten t ial n eed for oth er invasive in ter ven t ion s.
Extracranial Penetrating Injury (Fig. 9.7) • Th e ch oice of an open surgical or en dovascular approach for th e m an agem en t of pen et rat ing n eck inju ries is based on th e locat ion of th e inju r y (see Fig. 9.8). Th e surgical approach for pen et rat ing vascular injuries w ill be described in m ore det ail (see Operat ive Procedure, p. 145).
138
• A few elem ents of m anagem ent are com m on to all such injuries: ◦ Asser t ive m an u al com pression sh ould be used to con t rol bleeding in it ially. ◦ Th e air w ay m ust be secured, preferably by en dot rach eal in t ubat ion . If en dot rach eal in t u bat ion is n ot feasible, cricothyrotom y is th e n ext best opt ion for air w ay con t rol. Nasot rach eal in t u bat ion sh ou ld be avoided w h en p ossible because of th e possibilit y of cran ial or n asoph ar yngeal inju r y due to th e p en et rat ing injur y. ◦ En dova scu la r Tr ea t m en t ▪ En dovascular t reat m en t m ay be preferable for pat ien t s w ith Zon e I an d III injuries due to th e di cult y of surgical access to th ese areas (see Fig. 9.9). ▪ Covered sten t placem en t m ay be e ect ive for carot id lacerat ion s, p rovided th e lesion can be crossed . ▪ En dovascular ar terial occlu sion m ay be in dicated. Select ive occlusion of extern al carot id bran ch es is u su ally st raigh tfor w ard . In som e sit u at ion s, occlu sion of th e in tern al carot id or vertebral arter y m ay be n ecessar y to con t rol bleeding. Angiograph ic assessm en t of collateral circulat ion to th e a ected brain territor y can h elp determ in e th e risk of resultan t cerebral isch em ia. Sacri ce of an ar ter y sh ou ld in clu de occlusion of th e vessel both proxim al an d dist al to th e inju r y, if possible, to m in im ize th e ch an ce of ret rograde bleeding th rough th e distal segm en t of th e a ected arter y.
9
a
Managem ent of Traum atic Neurovascular Injuries
b
Fig. 9.5a, b Traumatic dissecting aneurysm (type III traumatic cerebrovascular injury). Patient with an asymptomatic cervical ICA dissecting aneurysm identi ed on screening CTA. Because signi cant enlargement was noted on follow-up surveillance imaging, it was treated with a covered stent. Angiograms (a) pre- and (b) post-stenting.
Fig. 9.6 Arterial occlusion (type IV traumatic cerebrovascular injury). Patient with asymptomatic complete occlusion of the ICA secondary to blunt trauma. The patient was managed conservatively and did not experience neurologic problems at tributable to the occlusion.
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If u n ch anged, con t in ue an t ip latelet agen t Fig. 9.10 Algorithm for the management of blunt intracranial cerebrovascular injury. MRP, magnetic resonance perfusion.
142
9
Managem ent of Traum atic Neurovascular Injuries
a
b Fig. 9.11a, b Intracranial blunt injury, dissection. (a) Patient with an intradural vertebral artery dissection (arrow) due to blunt trauma. The dissection caused a cerebellar hemorrhage. (b) The lesion was treated with endovascular occlusion.
Su sp ected pen et rat ing in t racran ial TCVI CTA eviden ce of vascu lar inju r y?
Yes
Dissect ion w ith h em orrh age DSA to assess collateral circu lat ion Poor collateral circu lat ion -an t iplatelet agen t Good collateral circu lat ion -en d ovascular vessel sacrifice
Dissect ion
An t iplatelet agen t Repeat CTA in 6 m on th s
No
Trau m at ic an eur ysm Treat m en t w ith en d ovascu lar or su rgical in ter ven t ion
Fist u la
Con sider t reat m en t (en dovascular or su rgical)
Un explain ed n eu ro deficit? If n o, n o fur th er w orku p If yes, DSA
New t rau m at ic an eu r ysm If resolved, D/C an t iplatelet agen t If u n ch anged, con t in u e an t iplatelet agen t
Fig. 9.12 Algorithm for the management of penetrating intracranial cerebrovascular injury.
143
I Cerebral Traum a and Stroke • Rem oval of foreign bodies sh ould be deferred un t il radio-
◦ If th e foreign body app ears to be proxim ate to or p rovid-
graph ic evalu at ion h as been com pleted. ◦ In pat ien t s w ith n o eviden ce of in t racran ial h em orrh age or cerebrovascular injur y, th e pen et rat ing object can be rem oved u n der gen eral an esth esia.
ing tam pon ade for a poten t ial vascular inju r y, th e foreign body sh ould be rem oved in th e operat ing room un der direct vision . Pen et rat ing in t racran ial inju r y (Fig. 9.13).
•
a
b Fig. 9.13a, b Penetrating intracranial injury. (a) Patient with a knife wound to the left temporal area. (b) The blade penetrated the squamous portion of the temporal bone. The tip was buried in the petrous bone (arrow), adjacent to the carotid canal and temporomandibular joint. Once it was established by imaging that the injury did not involve any arterial structures, the patient underwent craniotomy and rem oval of the knife blade.
144
9
Managem ent of Traum atic Neurovascular Injuries
Operative Procedure Surgical Management of Extracranial Penetrating Arterial Injuries – Zone II Positioning (Fig. 9.14a, b)
b
a
Figure
Procedural Steps
Pearls
Fig. 9.14
(a) Place a roll betw een the shoulder blades to extend the patient’s neck, and rotate the patient’s head aw ay from the side of injury. (b) Prep and drape the entire neck, upper chest, and low er face.
• Rem ove the cervical collar if the patient is wearing one.
145
I Cerebral Traum a and Stroke
Incision (Fig. 9.15)
146
Figure
Procedural Steps
Pearls
Fig. 9.15
Make a longitudinal incision along the anterior border of the sternocleidomastoid muscle (SCM).
• Err on m aking the incision too long rather than too short; it may extend from the ear lobe to the sternal notch if necessary.
9
Managem ent of Traum atic Neurovascular Injuries
Initial Dissection (Fig. 9.16)
Figure
Procedural Steps
Fig. 9.16
Use monopolar cautery to divide the platysma muscle. Mobilize and retract the sternocleidomastoid muscle laterally. Ligate and divide the transverse facial vein.
147
I Cerebral Traum a and Stroke
Carotid Artery Dissection (Fig. 9.17)
148
Figure
Procedural Steps
Pearls
Fig. 9.17
Use both blunt and sharp dissection to expose the carotid sheath.
• Avoid the area of injury by working around the hem atom a. All veins (including the internal jugular vein) m ay be ligated and divided if necessary. If both internal jugular veins are involved, one should be preserved. Use judicious and selective compression of bleeding arterial branches and veins as they are encountered.
9
Managem ent of Traum atic Neurovascular Injuries
Proximal and Distal Control (Fig. 9.18)
Figure
Procedural Steps
Pearls
Fig. 9.18
Once the ICA distal to the injury and the CCA or ICA proximal to the injury have been exposed, place either a clamp or an aneurysm clip on the artery in each location.
• Large perm anent aneurysm clips are usually su cient for the ICA, and a Fogart y clamp is usually necessary for the com m on carotid artery. Large aneurysm clips m ay also be used for temporary occlusion of external carotid artery (ECA) branches.
149
I Cerebral Traum a and Stroke
Repair of Arterial Injury (Fig. 9.19a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 9.19
(a) Repair the arterial injury primarily, w hen possible, w ith a running 6-0 nonabsorbable polypropylene mono lament stitch.
• Ligation and sacri ce of the ICA
(b) When primary repair is not possible, place a tubular polytetra uoroethylene (PTFE) interposition graft and secure w ith simple interrupted 6-0 polypropylene mono lament sutures. Remove the arterial clamps in the follow ing order: ECA, CCA, and ICA.
150
should be avoided; repair of the artery versus ligation results in an 8% versus 50% ischem ia stroke rate.10
9
Closing • Leave a drain in place. Close the wound w ith absorbable braided stitches in the platysm a m uscle and staples or stitches in the skin.
Postoperative Management Monitoring • All pat ien ts w ith cerebrovascular injuries sh ould be m on i-
•
•
tored in a n eurologic in ten sive care un it during th e acute p h ase, w ith frequen t n eu rologic exam in at ion s, vit al sign m on itoring, an d daily laborator y st u dies. Blood pressu re m on itoring w ith an arterial lin e is p referable for p at ien t s w ith labile blood p ressu re or for th ose requ iring con t in uous m edicat ion in fusion s for blood pressure con t rol. Main ten an ce of systolic blood pressu re bet w een 90 an d 180 m m Hg is adequ ate for m ost pat ien t s. Th e n eed for invasive in t racran ial m on itoring is dictated by st an dard n eurosurgical criteria (e.g., for pat ien t s w ith elevated in t racran ial p ressu re du e to h ead injur y).
Medication • An t ithrom bot ic th erapy w ith aspirin (325 m g daily) is in di• • •
cated for m ost pat ient s w ith t raum at ic cerebrovascular injur y. More aggressive an t ith rom bot ic th erapy, w ith system ic an t icoagulat ion , m ay be n ecessar y for pat ien ts w ith sign i can t in t ralu m in al arterial or ven ou s th rom bosis. Du al an t ip latelet th erapy (e.g., asp irin an d clop idogrel) is n ecessar y for all p at ien t s receiving a vascu lar sten t . In m ost cases, an t ith rom bot ic th erapy for 3 m on th s is app ropriate.
Radiographic Imaging • Follow -u p im aging of t rau m at ic cerebrovascular lesion s w ith CTA at a 3- to 6-m on th in ter val is u sefu l to m on itor d issect ion s an d to ch eck for th e developm en t or progression of t raum at ic an eur ysm s.
Further Management • An out patient clinic follow -up evaluation should be com pleted 3 to 6 m onths after discharge.
Special Considerations Antithrombotic Therapy • Th e u se of an t ith rom bot ic m edicat ion is a reason able op t ion in pat ien t s w ith cerebrovascular injuries as a m easure to preven t th rom boem bolic isch em ic st roke. How ever, all
Managem ent of Traum atic Neurovascular Injuries
an t ith rom bot ic m edicat ion s, in clu ding an t iplatelet agen t s an d an t icoagu lat ion , carr y a risk of h em orrh agic com plicat ion s, part icularly in pat ien t s w ith in t racran ial h em orrh age or polyt raum a. Alth ough level III clin ical eviden ce an d gu idelin es about th e use of an t ith rom bot ic m edicat ion s in t rau m a p at ien ts are lacking, th e au th ors of th is ch apter recom m en d th e use of aspirin in m ost pat ien ts w ith cerebrovascu lar in ju ries. For p at ien ts w ith t rau m at ic in t racran ial m ass lesion s (e.g., subdural h em atom as or clin ically sign i can t in t racerebral h em orrh age), an d/or for w h om cran ial surger y is an t icip ated or h as been don e, avoiding an t ith rom bot ic m edicat ion s seem s p ru den t .
References 1. Hugh es KM, Collier B, Green e KA, Ku rek S. Trau m at ic carot id arter y dissect ion : a signi cant in ciden t al n ding. Am Surg 2000;66(11):1023–1027 2. Bi W L, Moore EE, Ryu RK, et al. Th e u n recogn ized ep idem ic of blun t carot id arterial injuries: early diagn osis im proves n eurologic ou tcom e. An n Su rg 1998;228(4):462–470 3. Bi W L, Moore EE, O ner PJ, et al. Blunt carotid arterial injuries: im plications of a n ew grading scale. J Traum a 1999;47(5):845–853 4. Bi W L, Moore EE, Elliot t JP, et al. Th e devast at ing p oten t ial of blun t vertebral arterial injuries. An n Surg 2000;231(5):672–681 5. Bi W L, Ray CE Jr, Moore EE, et al. Treat m en t-related ou tcom es from blu n t cerebrovascu lar inju ries: im p or t an ce of rou t in e follow up ar teriography. An n Surg 2002;235(5):699–706; discussion 706–707 6. Stein DM, Bosw ell S, Sliker CW, Lu i FY, Scalea TM. Blu n t cerebrovascular injuries: does t reat m en t alw ays m at ter? J Traum a 2009;66(1):132–143; discussion 143–144 7. Nason RW, Assu ras GN, Gray PR, Lipsch it z J, Bu rn s CM. Pen et rat ing n eck inju ries: an alysis of experience from a Can adian t raum a cen t re. Can J Surg 2001;44(2):122–126 8. Th om a M, Navsaria PH, Edu S, Nicol AJ. An alysis of 203 pat ien t s w ith penet rat ing n eck injuries. World J Surg 2008;32(12): 2716–1723 9. Ku eh n e JP, Weaver FA, Papan icolaou G, Yellin AE. Pen et rat ing t raum a of th e in ternal carot id arter y. Arch Surg 1996;131(9): 942–947; discussion 947–948 10. Ram adan F, Rutledge R, Oller D, How ell P, Baker C, Keagy B. Carot id ar ter y t rau m a: a review of con tem p orar y t rau m a cen ter experien ces. J Vasc Su rg 1995;21(1):46–55; d iscu ssion 55–56 11. Sekh aran J, Den n is JW, Velden z HC, Miran da F, Fr ykberg ER. Con t in u ed exp erien ce w ith p hysical exam in at ion alon e for evalu at ion an d m an agem en t of p en et rat ing zon e 2 n eck inju ries: result s of 145 cases. J Vasc Surg 2000;32(3):483–489 12. McKevit t EC, Kirkpat rick AW, Vertesi L, Granger R, Sim on s RK. Iden t ifying p at ien t s at risk for in t racran ial an d ext racran ial blu n t carot id inju ries. Am J Su rg 2002;183(5):566–570 13. Ven t ureyra EC, Higgin s MJ. Traum at ic in t racran ial an eur ysm s in ch ildh ood and adolescen ce. Case repor t s and review of th e literat ure. Ch ilds Ner v Syst 1994;10(6):361–379 14. Holm es B, Harbaugh RE. Traum at ic in t racran ial an eur ysm s: a con tem porar y review. J Traum a 1993;35(6):855–860 15. Dusick JR, Esposito F, Malkasian D, Kelly DF. Avoidan ce of carot id ar ter y injuries in t ran ssph enoidal surger y w ith th e Dop p ler p robe an d m icro-h ook blad es. Neu rosu rger y 2007; 60(4 Su ppl 2):322–328
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I Cerebral Traum a and Stroke 16. Aarabi B. Trau m at ic an eu r ysm s of brain du e to h igh velocit y m issile h ead w ou nds. Neurosurger y 1988;22(6 Pt 1):1056–1063 17. du Trevou MD, van Dellen JR. Pen et rat ing st ab w ou n d s to th e brain : th e t im ing of angiography in p at ien t s presen t ing w ith th e w eapon already rem oved. Neurosurger y 1992;31(5):905–911; discu ssion 911–912 18. Am irjam sh idi A, Rah m at H, Abbassiou n K. Trau m at ic an eu r ysm s an d ar terioven ou s st u las of in t racran ial vessels associated w ith
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pen et rat ing h ead inju ries occu rring d u ring w ar: p rin ciples an d pitfalls in diagn osis an d m an agem en t . A su r vey of 31 cases an d review of th e literat ure. J Neurosurg 1996;(5):769–780 19. Miller PR, Fabian TC, Croce MA, et al. Prospective screening for blunt cerebrovascular injuries: analysis of diagnostic m odalities and outcom es. Ann Surg 2002;236(3):386–393; discussion 393–395 20. Beletsky V, Nadareishvili Z, Lynch J, et al. Cervical arterial dissection: tim e for a therapeutic trial? Stroke 2003;34(12):2856–2860
10
Management of Venous Sinus Injuries Laurence Davidson and Rocco A. Arm onda
Introduction Major du ral ven ou s sin u ses form at th e d u ral re ect ion s w h ere th e super cial an d deep layers of th e dura split an d th e deep layer fu ses to form th e falx cerebri an d th e ten torium cerebelli. Inju r y to th e du ral ven ou s sin u ses m ay be en cou n tered in p en et rat ing an d n onpen et rat ing h ead t rau m a or can resu lt from plan n ed or acciden tal disrupt ion during a cran iotom y.1–3 Th e dural ven ous sin us h as a th ree-sided lum en th at is teth ered lat erally by th e adjacen t du ra m ater an d deep ly by th e falx cerebri or ten torium cerebelli. Hem orrh age can arise from th e sin us roof, lateral w alls, ven ou s lakes, arach n oid gran u lat ion s, em issar y vein s, or cort ical vein t ribu taries. Th e decision to repair versu s sacri ce th e sin us is dependen t on th e locat ion of injur y. W h en repair is in dicated, th e t ype an d exten t of inju r y w ill largely dict ate th e opt im al repair tech n iqu e, w h ich ranges from direct repair to segm en t al replacem en t .
• Cerebral angiography ◦ Alth ough angiography rem ain s th e gold stan dard for im ag-
•
Medication • An t im icrobial prophylaxis is in it iated. • An t iseizure prophylaxis is in it iated.
Operative Field Preparation • Gen eral pat ien t p osit ion ing ◦ Secu re th e p at ien t to th e table, as u p to 60 degrees of re-
Indications • Trau m at ic injur y resu lt ing in sign i can t h em orrh age or • •
•
th rom bosis Resect ion of an in lt rat ing n eoplasm Th ree areas require repair to m ain tain paten cy 1,4 ◦ Posterior t w o-th irds of th e su p erior sagit t al sin u s ◦ Torcu lar h eroph ili ◦ Dom in an t t ran sverse sin u s All oth er areas m ay be ligated w ith m in im al risk 1,4
Preprocedure Considerations
•
•
Radiographic Imaging • Com puted tom ography (CT) ◦ Du ral ven ou s sin u s inju r y sh ou ld be su sp ected if im aging
◦
sh ow s an ep id u ral h em atom a in th e region of a m ajor ven ou s sin us.5 In on e st u dy, 89% of ep id u ral h em atom as arising from a du ral ven ou s sin us h ad an associated fract ure th at crossed th e sin us.1 Posterior fossa ep id u ral h em atom as involve th e du ral ven ou s sin u ses in 42.5% of cases.6 CT ven ography (CTV), w hich requires the adm inistration of intravenous contrast and is taken during the venous phase, can be diagnostic of sinus throm bosis. The em pt y delta sign m ay be seen in the area of sinus th rom bosis.7 CTV is indicated w hen there is a depressed skull fracture over a dural venous sinus, w hich can cause sinus stenosis and throm bosis.8,9
ing th e du ral ven ous sin uses, it is invasive an d t im e con su m ing, w h ich ren ders it im pract ical in th e set t ing of acu te t raum a. Pre o pe rative im aging (Fig. 10.1).
•
verse Tren delen bu rg m ay be n eeded to m in im ize in t racran ial ven ou s p ressu re if bleeding is p rofu se. ◦ Th e inju red du ral ven ou s sin u s segm en t sh ou ld be at th e h igh est poin t of th e op erat ive eld. ◦ Avoid excessive n eck rotat ion or exion . ◦ A bilateral craniotom y exposure is indicated to address injury to the superior sagittal sinus. A supra- and infratentorial ap proach is necessary to address injury to the transverse sinus. Measu res to m axim ize cran ial ven ou s ou t ow ◦ Avoid com pressive air w ay t ap e. ◦ Min im ize jugu lar com p ression from a rigid cer vical collar. ◦ Avoid excessive n eck rotat ion or exion . ◦ In tern al jugu lar cen t ral ven ou s lin es are con t rain dicated due to th e possibilit y of iat rogen ic th rom bosis an d im pairm en t of cran ial ven ou s ou t ow. Blood loss ◦ Large volu m e h em orrh age m ay occu r from th e inju red ven ou s sin u s. Sign i can t losses m ay also occu r—both preop erat ively an d in t raop erat ively—from scalp , bon e, an d brain . ◦ Packed red blood cells, platelet s, an d fresh frozen p lasm a m u st be available in th e op erat ing room . Ven ou s air em bolism ◦ Ven ou s air em bolism m ay occu r w h en th e h ead is elevated above th e h eart , resu lt ing in n egat ive p ressu re in th e du ral ven ou s sin u s—allow ing air to en ter an d becom e t rap ped in th e righ t at rium . ◦ A fall in th e en d t idal p CO2 an d hypoten sion m ay en sue. St rong con siderat ion sh ould be given to th e use of cap n ography, a precordial Dop pler probe, an d an ar terial lin e. Air em bolism p rodu ces “w ash ing m ach in e” sou n ds by Dop pler. ◦ Rem oval of air from th e righ t at riu m is p ossible if a righ t at rial cath eter—placed via th e brach ial or subclavian rou te—is in place.
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I Cerebral Traum a and Stroke
Fig. 10.1 CT sagit tal reconstruction demonstrating extensive, supra- and infratentorial epidural hematoma suggestive of a transverse sinus injury.
• Segm en tal sin u s rep lacem en t ◦ If substantial sinus disruption is anticipated, vascular
◦ If sten osis is likely to resu lt from p rim ar y su t u re repair, a
reconstruction equipm ent should be available, including a properly sized temporary vascular shunt, Fogarty balloon catheters, nonabsorbable vascular suture, and a vein allograft.
Operative Management Treat m en t is discu ssed sep arately for th e follow ing p ar ts of th e ven ou s sin u s system : an terior on e-th ird of th e su p erior sagit t al sin u s, p osterior t w o-th irds of th e su p erior sagit t al sin u s, torcular h eroph ili, an d d om in an t t ran sverse sin us.
General Considerations by Anatomic Location
•
• Su p erior sagit t al sin u s—an terior on e-th ird ◦ Th e m ajorit y of inju ries in th is area can be m an aged w ith
•
154
tam pon ade tech n iques or direct sut ure repair if th e lacerat ion is sm all. ◦ Lacerat ion s th at are too large to su t u re directly often can be t reated w ith a sut ured, bolstered patch . ◦ Lesion s th at can n ot be repaired can be t reated relat ively safely w ith sin u s ligat ion via an en circling su t u re or vascu lar clips. Su p erior sagit t al sin u s—p osterior t w o-th irds ◦ Th is p or t ion of th e sin u s sh ou ld be rep aired or rep laced in vir t u ally all cases, bu t especially w h en m ajor cor t ical ven ou s drain age is involved. ◦ Avoid p rim ar y su t u re closu re th at com p rom ises greater th an 50% of th e sin us lu m en , as th is m ay be m ore likely to resu lt in com prom ised ow an d even t ual sin us occlusion .
•
patch sh ould be placed. ◦ Rep lacem en t of segm en ts of th e su p erior sagit t al sin u s is th e m ost ext rem e of in ter ven t ion s, reser ved on ly for th ose cases involving eith er th e m ajorit y of th e dorsal w all or both lateral w alls, in w h ich a sut ured patch can n ot recon st ru ct a lu m en at least 50% of th e origin al size. ◦ Kapp et al develop ed an in tern al sh u n t for u se du ring sin u s recon st ru ct ion .3,4 Th is w as m ade of a p ed iat ric en dot rach eal t ube w ith a pediat ric t rach eostom y cu placed at each en d. Sin dou an d Alvern ia avoided th e balloon sh u n t an d Fogar t y balloon cath eter du e to risk of inju r y to th e sin u s en doth eliu m , advocat ing, in stead, for direct packing of th e lum en w ith h em ost at ic m aterial.2 Both em ph asize th e n eed for sin us th rom bectom y of th e proxim al an d distal en ds of th e sin u s repair to en sure patency. Torcular h eroph ili ◦ Inju ries th at su bst an t ially disru pt th e torcu lar h erop h ili are rarely sur vivable an d, in m ost cases, th e clin ical grade of th e pat ien t is su ch th at expect an t m an agem en t—w ith out su rgical in ter ven t ion —m ay be app ropriate. ◦ Th e tech n iqu es for t am p on ade, prim ar y rep air, an d p atch ing described for inju ries to th e sup erior sagit tal sin u s also ap p ly to th e torcu lar h erop h ili.1 Dom in an t t ran sverse sin u s ◦ Th e tech n iqu es for t am p on ade, prim ar y rep air, an d p atch ing described for inju ries to th e sup erior sagit tal sin u s also ap p ly to th e su p erior sagit t al sin u s. ◦ Sin d ou et al d escr ibed a byp ass of t h e t ran sverse sin u s to t h e exter n al jugu lar vein u sin g a sap h en ou s vein graft in a p at ien t w it h bilateral t ran sverse sin u s t h rom bosis.10 Met icu lou s w ou n d closu re is n ecessar y to p reven t com p ression an d su bsequ en t t h rom bosis of t h e su bcu t an eou s vein graft .
10
Managem ent of Venous Sinus Injuries
Operative Procedure Surgical Approach to Injuries of the Anterior Third of the Superior Sagittal Sinus Positioning (Fig. 10.2)
Figure
Procedural Steps
Pearls
Fig. 10.2
The patient is positioned supine, w ith the head elevated above the heart. The patient should be secured to the table so as to allow an angle of elevation up to 60 degrees, if necessary.
• Anesthesia m onitoring for venous air em boli (VAE) should •
include precordial Doppler, end-tidal pCO2 , and placem ent of a right atrial catheter (to perm it VAE retrieval). In severe cases, consider preparation for greater saphenous vein harvest.
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Incision (Fig. 10.3)
156
Figure
Procedural Steps
Pearls
Fig. 10.3
The orientation of the incision w ill be dictated by the speci c location of the injury.
• In general, an incision allowing exposure of both sides of the superior sagit tal sinus or providing access to the supra- and infratentorial compartments—in the case of a transverse/sigm oid injury—is advised.
10
Managem ent of Venous Sinus Injuries
Craniotomy (Fig. 10.4a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 10.4
The position of bur holes depends upon the anatomy of the speci c fracture.
• Fracture fragm ents
(a) If a nondepressed, linear fracture w ith suspected dural sinus laceration is present, consider leaving a bony shelf adjacent to the sinus in order to permit the use of epidural tacking stitches that might tamponade the lacerated sinus.
should be elevated in stages; defer rem oval of any fragm ent directly over the sinus until last.
(b) If fracture fragments appear depressed into the sinus, bur holes should be placed at the outer rim of the depressed segment—allow ing access to normal structures at the periphery. If the sinus is transected, bilateral bony exposure—both proximal and distal to the sinus injury—is necessary.
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Tamponade (Fig. 10.5a–c)
a
b
c
158
Figure
Procedural Steps
Pearls
Fig. 10.5
(a) Apply digital pressure, supplemented w ith “sinus patties” (a combination of 1 3 3 in cotton patties, hemostatic absorbable gelatin compressed sponge, and strips of hemostatic oxidized cellulose polymer). (b) Place epidural tack-up stitches w ith 4-0 braided nylon suture w hen usable bone is adjacent to the injury. (c) In some cases, the lateral convexity dura may be rolled tow ard the midline—over top the injured sinus segment and packing—and secured to form a “burrito.”
• Sinus pat ties should be prepared prior to exposure. • This com bination m ay be supplem ented with strips of hemostatic oxidized cellulose polym er and absorbable hemostatic m atrix paste or comparable hem ostatic agents. Also, cot ton balls and m uscle m ay be employed to bolster the tamponade.
10
Managem ent of Venous Sinus Injuries
Sinus Ligation (Fig. 10.6)
Figure
Procedural Steps
Pearls
Fig. 10.6
Injuries involving the anterior third of the superior sagittal sinus (in front of the coronal suture) may be amenable to ligation.
• Tamponade sinus bleeding during dissection
The sinus—anchored by the falx and convexity dura— rst must be released. Follow ing release of the sinus, ligation may be performed by a double ligature technique, using 2-0 nonabsorbable polypropylene suture or nylon. Make a double circular course beneath the sinus, into the falx and then more super cially, to be ligated and divided.
•
through the use of hemostatic agents and cot ton pat ties, augm ented with head of bed elevation (while m onitoring for VAEs). Alternatively, ligation m ay be perform ed with a surgical hem ostatic double clip at the inferior insertion of the sinus into the falx, near the crista galli. At tention m ust be paid to ensure that the clips cross the sinus completely.
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I Cerebral Traum a and Stroke
Sinus Patch (Fig. 10.7)
Figure
Procedural Steps
Pearls
Fig. 10.7
Lacerations that are too large to suture directly may be treated w ith a sutured, bolstered patch.
• This technique does not work well on the
Options for patch material include adjacent dura (curled over the sinus), temporalis fascia, fascia lata, and synthetic dura or vascular substitutes.
• Avoid direct suturing of the patch to the
lateral sinus walls.
double layers of the sinus.
A layer of muscle or hemostatic absorbable gelatin sponge should be interposed betw een the patch and underlying sinus laceration. Secure the patch—w ith a series of interrupted, peripherally placed 4-0 braided nylon or nonabsorbable polypropylene stitches—to the adjacent dura. Replace the overlying bone to bolster the sinus repair.
• Take care to avoid occluding the sinus or m ajor cortical veins in the area.
160
10
Managem ent of Venous Sinus Injuries
Sinus Interposition Graft (Fig. 10.8a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 10.8
Interposition grafting may be appropriate in cases of complete sinus disruption (posterior to the coronal suture), in patients deemed to be salvageable.
• Typical synthetic vascular graft m aterial is prone
The greater saphenous vein must be harvested in advance from the upper portion of the thigh. The graft should be reversed to prevent the valves from obstructing ow. (a) A temporary shunt should be placed, w ith heparin uid irrigation of the shunt tubing as w ell as the proximal and distal ends of the sinus. (b) The vein graft is placed around the shunt and incorporated w ith multiple, interrupted, end-to -end 6-0 nonabsorbable polypropylene stitches, leaving a small dorsal region to remove the shunt and tie the nal stitches.
•
to throm bosis in this location and should be avoided, if possible. Likewise, arterial grafts m ay progressively occlude from extensive arterial wall throm bosis. Cadaveric vein may be an option in rare cases. Historically, the vascular shunt featured a double balloon conf guration that allowed venous ow without bleeding around the shunt. More recently, other authors have described the use of a Rum ell vessel loop around the shunt proximally and distally to avoid endothelial sinus injury and delayed throm bosis.
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I Cerebral Traum a and Stroke
Variation for Injuries of the Posterior Tw o -thirds of the Superior Sagittal Sinus, Torcular Herophili, and Dominant Transverse Sinus Positioning (Fig. 10.9)
Figure
Procedural Steps
Pearls
Fig. 10.9
The approach to these sinus segments is best accomplished w ith the patient in prone position.
• Refer to Fig. 10.2 for details regarding
Injuries involving the middle third of the sinus may be approached in the supine position. Alternately, the patient may be in lateral position, w ith the falx cerebri parallel to horizontal and the head tilted up 45 degrees.
162
anesthetic adjuncts in this set ting.
10
Managem ent of Venous Sinus Injuries
Incision (Fig. 10.10)
Figure
Procedural Steps
Fig. 10.10
An inverted U-shaped incision permits access to the supratentorial and infratentorial compartments. A transverse, linear incision providing access to the bilateral hemispheres may be used to approach injuries to the middle third segment of the sagittal sinus.
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I Cerebral Traum a and Stroke
Craniotomy (Fig. 10.11)
164
Figure
Procedural Steps
Pearls
Fig. 10.11
The position of bur holes depends on the anatomy of the speci c fracture.
• The bony opening should perm it access to both sides of the sinus in question.
10
Managem ent of Venous Sinus Injuries
Direct Repair (Fig. 10.12)
Figure
Procedural Steps
Pearls
Fig. 10.12
The use of adjuncts discussed in Fig. 10.5 for tamponade may be e ective, but must be tempered by the risk of sinus and/or cortical vein occlusion.
• Tamponade is particularly poorly tolerated in the region of the central
Primary suture repair of lacerations may be attempted w ith 6-0 nonabsorbable polypropylene suture.
• Injury involving a single lateral wall at the junction of a venous lake,
sulcus when the vein of Trolard is involved.
• •
which does not respond to tamponade, m ay be isolated and treated with suturing parallel to the sagit tal plane along the sinus edge. Avoid prim ary suture closure that com prom ises . 50% of the sinus lum en. If stenosis is likely to result from prim ary suture repair, a patch should be considered.
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I Cerebral Traum a and Stroke
Sinus Patch (Fig. 10.13)
Figure
Procedural Steps
Pearls
Fig. 10.13
Lacerations that are too large to suture directly may be treated w ith a sutured, bolstered patch.
• Refer to Fig. 10.7 for details regarding •
Interposition grafting is a daunting proposition in this area. The vein graft must be oriented such that the valves allow ow from the anterior to posterior portions of the sinus in a nonlimiting fashion.
•
166
patching of the venous sinus. Replacement of a superior sagit tal sinus segm ent is reserved only for cases that involve both lateral walls or the m ajorit y of the dorsal wall, where a sutured patch cannot reconstruct a lum en at least 50% of the original size. Refer to Fig. 10.8 for details regarding interposition grafting.
10
Closing • Du ral closu re is perform ed w ith 4-0 braid ed nylon su t u re. • Th e bon e ap is reapproxim ated—if feasible—w ith an in t ra• • • •
cran ial plat ing system . Th e surgical site is irrigated w ith an t ibiot ic solu t ion . Met icu lou s h em ost asis is at t ain ed along th e skin edges. A subgaleal drain m ay be left in place if n ecessar y. Th e galea an d su bcut an eou s t issue are reapproxim ated w ith 2-0 braided absorbable sut ure inver ted st itch es. Th e skin is closed eith er w ith st aples or 3-0 nylon sut ure.
Managem ent of Venous Sinus Injuries
Medication • An t im icrobial prophylaxis is con t in u ed for 24 h ours. • An t iepilept ic prophylaxis is con t in ued for 7 days.
Radiographic Imaging • A CT scan is perform ed early in th e postoperat ive period to •
ru le ou t h em orrh age an d/or isch em ia. Im aging is repeated for any sign i can t ch ange in n eu rologic stat u s. Dedicated vascu lar im aging (CTV, m agn et ic reson an ce ven ograp hy, or angiography) m ay be app ropriate if th rom bosis is su sp ected. Po sto perative im aging (Fig. 10.14).
Postoperative Management
•
Monitoring
Special Considerations
• Th e pat ien t is m on itored in th e in ten sive care un it set t ing to •
• •
p erm it frequ en t n eurologic ch ecks an d con t in uous h em odyn am ic m on itoring. Invasive blood p ressu re m on itoring an d a cen t ral ven ou s cath eter are em ployed to provide con t in uous m on itoring of blood pressure an d volum e st at us. Blood pressure is m ain t ain ed in a n orm al range. Th e goal of in t raven ou s uid th erapy is euvolem ia. Th e h ead of th e bed is m ain t ain ed at 30 degrees. Invasive neurologic m onitors are placed if indicated by the patient’s overall neurologic status (Glasgow Com a Scale score 8).
Late Complications • Post-repair ven ous sin us sten osis or sin us com pression (e.g., from a dep ressed sku ll fract u re) in creases th e risk of delayed sin u s th rom bosis. Ven ou s sin u s th rom bosis m ay lead to p rogressive bilateral en ceph alopathy, in creased in t racran ial p ressure, cerebral edem a, in t raparen chym al h em orrh age, an d ven ou s in farct ion . Deep ven ou s h em orrh age an d in farct ion involving th e th alam us can occur w ith injur y to th e st raigh t sin u s at th e level of th e ten toriu m .
Fig. 10.14 Sagit tal CT reconstruction demonstrating resolution of extra-axial hematoma following repair of a transverse sinus injury.
167
I Cerebral Traum a and Stroke • Th e in dicat ion s for delayed cran iotom y or decom pressive cran iectom y in clu de: ◦ Elevated in t racran ial p ressu re n ot resp on sive to m axim al m edical th erapy ◦ Severe cerebral edem a or th e p resen ce of an in t racran ial h em atom a w ith im pen ding brain h ern iat ion ◦ Elevat ion of a dep ressed sku ll fract u re or rem oval of a foreign body w h en d u ral sin u s paten cy is com prom ised
References 1. Pricola KL, Zou H, Chang SD. Successful repair of a gunshot wound to the head w ith retained bullet in the torcular herophili. World Neurosurg 2011;76(3–4):e361–364 2. Sin dou MP, Alvern ia JE. Resu lt s of at tem pted radical t u m or rem oval an d ven ous repair in 100 con secut ive m en ingiom as involving th e m ajor dural sin uses. J Neurosurg 2006;105(4): 514–525 3. Kap p JP, Gielch in sky I. Man agem en t of com bat w ou n ds of th e du ral ven ou s sin u ses. Su rger y 1972;71(6):913–917
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4. Kap p JP, Sch m idek HH. Su rger y of th e cerebral ven ou s system . In : Kapp JP, Sch m idek HH, eds. Th e Cerebral Venous System an d It s Disorders. Orlan do: Gr u n e & St rat ton , In c.; 1984:597–623 5. Ch ee CP, Habib ZA. Hyp oden se bu bbles in acu te ext radu ral h aem atom as follow ing ven ous sin us tear. A CT scan appearan ce. Neuroradiology 1991;33(2):152–154 6. Bor-Seng-Sh u E, Agu iar PH, de Alm eida Lem e RJ, Man del M, An drade AF, Marin o R, Jr. Epidural h em atom as of th e posterior cran ial fossa. Neurosurg Focus 2004;16(2):ECP1 7. Rao KC, Kn ip p HC, Wagn er EJ. Com pu ted tom ograph ic n dings in cerebral sin us an d ven ous throm bosis. Radiology 1981; 140(2):391–398 8. Forbes JA, Reig AS, Tom ycz LD, Tulipan N. Intracran ial hypertension caused by a depressed skull fracture resulting in superior sagit tal sin us throm bosis in a pediatric patient: treatm ent w ith ven triculoperitoneal shunt insertion. J Neurosurg Pediatr 2010;6(1):23–28 9. Yokot a H, Egu ch i T, Nobayash i M, Nish ioka T, Nish im u ra F, Nikaido Y. Persisten t in t racran ial hyperten sion caused by superior sagitt al sin us sten osis follow ing depressed skull fract u re. Case repor t an d review of th e literat u re. J Neu rosu rg 2006;104(5):849–852 10. Sin dou M, Mercier P, Bokor J, Bru n on J. Bilateral th rom bosis of th e t ran sverse sin u ses: m icrosu rgical revascu larizat ion w ith ven ou s byp ass. Su rg Neu rol 1980;13(3):215–220
II
Spinal Emergency Procedures
11
Application of Closed Spinal Traction Nirit W eiss
Introduction
Preprocedure Considerations
Em ergen cy closed spin al t ract ion m ay be perform ed for p at ien ts w h o p resen t w ith cer vical spin al m isalign m en t an d/ or in st abilit y secon dar y to t raum a. Use of ligh ter w eigh t (5–10 lb) can m ain t ain align m en t an d im m obilize an un st able sp in e, if closed t ract ion redu ct ion is n ot d eem ed app rop riate at th e t im e. Reduct ion of fract ure dislocat ion an d realign m en t w ith in creased w eigh t (10–80 lb) can decom press th e spin al cord an d n er ve root s. After su ccessful applicat ion of t ract ion , bracing or su rger y m ay be deem ed appropriate. If t ract ion is un su ccessfu l, su rger y likely follow s. Man ipulat ion u n der an esth esia (MUA) m ay be h elp ful in pat ien ts w h o fail aw ake in lin e t ract ion redu ct ion .1 Weigh ted in lin e h alo ring t ract ion can be converted to long-term h alo-vest im m obilizat ion if n eeded. Most com m on ly u sed t ract ion opt ion s are Gard n er-Wells (G-W) tongs an d Halo rings.
Radiographic Imaging • X-ray an d/or com p u ted tom ograp hy (CT) eviden ce of fract u re, •
Indications • Cer vical spin al m isalign m en t due to t raum at ic fract ure/ • • • • • • • •
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dislocat ion Sp in al cord/n er ve root com p ression du e to m isalign m en t Cer vical spin al in st abilit y du e to t rau m at ic fract u re or ligam en tou s in stabilit y requ iring im m obilizat ion th at can n ot be adequ ately ach ieved w ith extern al orth oses alon e Aw ake, coop erat ive p at ien t Availabilit y of radiographic/clinical m onitoring during reduction Absen ce of skull fract ure or prior bur hole at proposed pin sites Absen ce of occipitoatlan tal or atlan toaxial dissociat ion or com plete ligam en tous injur y at any level Absen ce of fract ure/in st abilit y at level rost ral to in ten ded level of t reat m en t Absen ce of kn ow n sign i can t associate t raum at ic cer vical disk h ern iat ion , w h ich can w orsen n eurologic de cit un der t ract ion
su blu xat ion , m isalign m en t , in stabilit y (Fig. 11.1). Role of p ret ract ion m agn et ic reson an ce im aging (MRI) rem ain s con t roversial2 : On e-th ird to on e-h alf of pat ien t s w ith facet su blu xat ion h ave eviden ce of disk h ern iat ion or disru p t ion on MRI. In lin e t ract ion in th e presen ce of ven t ral cord com pression m ay lead to n eurologic injur y. How ever, less th an 1% of pat ien t s have been foun d in st u dies to h ave perm an en t n eu rologic deteriorat ion resu lt ing from app licat ion of cer vical t ract ion —despite th e presen ce of h ern iated ven t ral disks. Depen ding on th e t im e n eeded to obtain th e MRI, th e ben e t s of early reduct ion sh ould be w eigh ed again st th e risk of reduct ion in th e face of poten t ial un iden t i ed ven t ral com pression from disk h ern iat ion . In aw ake, cooperat ive p at ien ts, physical exam can be m onitored w h ile in creasing t ract ion w eigh t , an d p ret raction MRI m ay h ave low er u t ilit y. In u n conscious pat ien t s, sign i can t e ort s to obt ain pret ract ion MRI sh ou ld be m ad e. Pat ien t s w ith in com p lete inju ries h ave greatest risk of n eu rologic d eteriorat ion .
Medication • System ic: Non sedat ing pain m edicat ion (m orph in e, fen t anyl) •
an d m u scle rela xan t (diazep am ) in t raven ou sly (IV) as n eeded to allow for pat ien t cooperat ion an d successful reduct ion . Local: 1% lidocain e or 1% lidocain e/0.5% bu p ivacain e (1:1 m ixt u re) ap p lied to scalp an d pericran iu m of p lan n ed p in site locat ion s.
Operative Field Preparation • Alcoh ol prep follow ed by povidone/iodine to plann ed pin sites. • An t ibacterial (bacit racin ) oin t m en t to pin s prior to placem en t .
11
Application of Closed Spinal Traction
a
b Fig. 11.1 Lateral radiograph in patient with high-grade spondylolithesis at C4-5 due to bilateral facet dislocation after traction tongs placement and prior to weight application.
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Operative Procedure Positioning (Fig. 11.2)
172
Figure
Procedural Steps
Pearls
Fig. 11.2
Patient is positioned for application of traction, typically supine, head in neutral position.
• It is easier to place an “open” halo ring than a closed ring while supine. Check lateral X-ray in position prior to proceeding. If one needs to reduce kyphosis, a shoulder roll can be placed. If the plan is to eventually place in halo vest, one can “preplace” the back of the halo vest for the patient to lie on.3
11
Application of Closed Spinal Traction
Selection of Pin Sites (Fig. 11.3a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 11.3
(a) Gardner-Wells tongs. Tw o pin sites are required. (A, green) The ideal pin site placement is along the superior temporal line, above the temporalis muscle belly (mark as transparency below skin), approximately 3 to 4 cm above pinna. For neutral traction, pin directly in line above external auditory meatus (EAM). To induce a exion correction (e.g., of jumped facets), (B, red) place 3 cm posterior to EAM; to induce an extension (e.g., for subluxation), (C, blue) place 3 cm anterior to EAM, along the superior temporal line. After preparation w ith alcohol and povidone iodine, local anesthetic is injected. (b) Halo ring. Select four pin sites, each marked w ith a pen: tw o anterior, tw o posterior. The tw o anterior sites should be 1 cm above orbital rim, above lateral half of the orbit (to avoid the supraorbital and supratrochlear nerves and the frontal sinus). Posterior pins should be in region of mastoid. After preparation w ith alcohol and povidone iodine, local anesthetic is injected.
• Halo rings are available in MRI compatible m odels which • •
•
•
can facilitate later im aging. Weights are t ypically not MRI-compatible and m ust be removed for MRI im aging. Ensure there are no skull fractures or bur holes in region of proposed pin sites. Do not place pins into thin squam ous temporal bone. Select pin sites while assistant holds the halo ring in place, or use “suction cup” stabilizing posts to hold ring while selecting appropriate sites. Pin sites should be selected to allow for the ring to sit symmetrically around the head. Pin sites should be selected to allow for a 1- to 2-cm space circum ferentially bet ween the scalp and the halo ring. Pins should be placed in holes that allow for m ost perpendicular entry into skull.4 Prep with alcohol followed by povidone iodine. Inject lidocaine or lidocaine/bupivacaine mixture as above into proposed pin sites, into scalp and pericranium. May incise scalp prior to pinning to avoid contamination with skin ora.
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Placement of Pins (Fig. 11.4a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 11.4
(a) Gardner-Wells tongs. Place pins through the tongs into scalp and pericranium. Tighten both pins simultaneously, until torque indicator on one pin protrudes approximately 1 to 2 mm, indicating adequately tightened screws.
• Pay at tention to eyes and eyebrows to avoid pinning
(b) Halo ring. Tighten two diametrically opposed screws simultaneously until “ nger tight.” Then tighten the other two screw s simultaneously until “ nger tight.” At this point, use torque w rench to adequately and safely secure pin tightness to preset maximal torque (8 in-lb for adults).
174
•
eyes open or closed. For children: Use lower nal torque for tightening (4–8 in-lb for children age 3–10, 2–4 in-lb for children under age 3).5 Use multiple (6–10) pins in order to distribute pressure evenly circum ferentially and avoid fracture or excessive skull penetration. Also, use specially supplied pediatric pins with short tips and wide ange, if available.6
11
Application of Closed Spinal Traction
Placement of Traction Weights and Counter-Traction (Fig. 11.5)
Figure
Procedural Steps
Pearls
Fig. 11.5
Secure a knotted rope to tongs or halo ring, through a pulley at head of bed, and hang weights from there.
• If stabilizing an unstable fracture bet ween occiput and C2, begin with 5 lb, and advance to • •
Secure ankles, wrists, and shoulders w ith padded roped restraints to foot of bed to prevent patient from sliding up on bed w hen placed in traction.
10 lb if radiographs show no change. Below C2, begin with 10 lb to overcome weight of head through C2, and then 5 lb per level below C2 (e.g., 20 lb for C4 fracture). Cervical traction is best perform ed under uoroscopy, or obtain serial X-rays im m ediately after weight change, and in 30-m in intervals to gauge progress. Follow the neurologic exam every 10 m inutes. One m ay add weights in 5-lb intervals and recheck radiograph. Stop when observe: (1) successful spinal realignm ent radiographically, (2) neurologic deterioration, (3) undesired radiographic changes (worsening m isalignm ent, distraction at more rostral disk level with widened disk space or splayed spinous processes or facet joints), and/or (d) patient complains of severe discom fort.
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Placement of Vest (Fig. 11.6)
Figure
Procedural Steps
Pearls
Fig. 11.6
Select correct vest size for the patient. Connect posterior ring to posterior vest w ith upright post.
• Important note: Every brand and st yle of halo vest and
Connect anterior ring to anterior vest w ith upright posts. Connect anterior/posterior halves of vest to each other. Once in place, secure the ring to the posts at each point w ith torque w rench, maintaining head in correct alignment. Check post-placement X-rays immediately after placement and w hen upright day 1 and day 3.
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• • • •
head ring com es with a detailed set of instructions for application. It is recom m ended to review these instructions carefully prior to applying the apparatus Incorrect sizing of vest can lead to loss of alignm ent. If posterior vest has not be “preplaced,” patient can be logrolled, or elevated 30 degrees while head held in gentle manual traction. Tape wrench to anterior vest for easy access in em ergency. Watch for pressure ulcers at sites of excess pressure on shoulders, back, and chest.
11
Application of Closed Spinal Traction
Postoperative Imaging (Fig. 11.7)
Figure
Procedural Steps
Fig. 11.7
Lateral radiograph of cervical spine after tongs traction in patient depicted in Fig. 11.1. Spinal alignment at C4-5 has improved after serial w eights w ere applied, but the patient required open reduction and xation. It is important to obtain imaging after halo or traction placement to verify alignment of the injured segment.
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Postoperative Management Monitoring • Mon itor n eu rologic st at u s an d vital sign s ever y 2 h ou rs. • Mon itor for skin breakdow n /decu bit is u lcers.
Medication • Pain m an agem en t an d m u scle relaxat ion can be adm in istered.
correct ion w ith th e goal of reducing th e spin e to th e prefract ure sagit tal cu r vat u re. Over-dist ract ion or correct ion w ith h eavier w eigh t s qu ickly lead s to u n con t rolled re- or m isalign m en t an d n eu rologic inju r y. For t ract ion in pat ien ts w ith locked facet s, apply gen tle exion force for bilateral locked facet s, or exion plu s gen tle rot at ion tow ard side of locked facet for u n ilateral locked facet s. In crem en t al in creases in w eigh t can be ap p lied u n t il locked facets becom e p erch ed. On ce p erch ed, slow ly redu cing w eigh t s to 5 to 10 lb w h ile gen tly exten ding (by sliding in a sh oulder roll) redu ces th e dislocat ion . On ce redu ced, m ain t ain 5 to 10 lb w eigh t s for st abilizat ion u n t il de n it ive t reat m en t (i.e., su rger y) is accom plish ed.
Radiographic Imaging • Obt ain lateral X-ray w ith any w eigh t ch ange, w ith any bed t ran sfer, an d on ce daily as rout in e.
Pin Site Management • Gardner-Wells pins are checked at 24 and 48 hours to ensure
•
that the spring-loaded force indicator is protruding. Halo pins are re-torqued to 8 in-lb once at 24 hours, and again at 48 hours. Additional tightening beyond this point can lead to skull penetration, skull fracture, pin loosening, and/or infection. Maintain t w ice-daily pin site cleaning w ith hydrogen peroxide or povidon e iodine oin tm ent.
Further Management • After su ccessfu l realign m en t , decide to brace, p lace in h alo •
vest (see Fig. 11.6), or operate. After failed realign m en t , a decision to op erate is u su ally m ade.
Special Considerations Pediat ric pat ien t s h ave special con cern s regarding n u m ber of pin s an d pin torque pressures (see above). In pat ien t s w ith an kylosing spon dylit is,7,8 ligh t cer vical t ract ion (, 5 or 10 lb) is ad vised. Prolonged t ract ion w ith ligh t w eigh ts m ay lead to desired
178
References 1. Lu K, Lee T, Ch en H. Closed redu ct ion of bilateral locked facet s of th e cer vical spin e un der gen eral an esth esia. Act a Neuroch ir (Wein ) 1998;40:1055–1061 2. Sect ion on Disord ers of th e Sp in e an d Perip h eral Ner ves of th e Am erican Associat ion of Neu rological Su rgeon s an d Th e Congress of Neu rological Su rgeon s: In it ial closed redu ct ion of cer vical spin e fract u re-dislocat ion injuries. Neurosurger y 2002;50(suppl 3):s44–50 3. Goldstein R, Deen HG, Zim m erm an RS, Lyon s MK. “Preplacem en t” of th e back of th e h alo vest in pat ien t s un dergoing cer vical t ract ion for cer vical spin e injuries: a tech n ical n ote. Surg Neurol 1995;44:476–478 4. Cop ley LA, Pep e MD, Tan V, Sh eth N, Dorm an s JP. A com p arison of variou s angles of h alo p in in ser t ion in an im m at u re sku ll m od el. Spin e 1999;24:1777–1780 5. Arkader A, Hosalkar HS, Dru m m on d DS, Dorm an s JP. An alysis of h alo-or th osis applicat ion in children less th an th ree years old. J Ch ild Or th op 2007;1:337–344 6. Cop ley LA, Pep e MD, Tan V, Dorm an s JP, Gabriel JP, Sh eth NP, Asada N. A com p arat ive evalu at ion of h alo p in d esign s in an im m at ure skull m odel. Clin Orth op 1998;357:212–218 7. Kan ter AS, Wang MY, Mu m m an en i PV. A t reat m en t algorith m for th e m anagem en t of cer vical spin e fract ures an d deform it y in pat ien t s w ith ankylosing spon dylit is. Neurosurg Focus 2008;24(1):E11–17 8. Th u m bikat P, Harih aran RP, Ravich an d ran G, McClellan d MR, Math ew KM. Sp in al cord inju r y in pat ien t s w ith an kylosis spon dylit is: a 10-year review. Spin e 2007;32(26):2989–2995
12
Emergency Management of Odontoid Fractures Sanjay Yadla, Benjam in M. Zussm an, and Jam es S. Harrop
Introduction
Indications
Th e od on t oid p rocess, or d e n s, is t h e b ony con ical p roje ct ion of t h e a xis (C2), arou n d w h ich t h e r in g-sh a p e d at las (C1 ) e n a bles rot at ion al m ove m e n t of t h e h ea d . Fract u res of t h e od on toid p rocess con st it u t e ap p roxim at ely 15 % of all ce r vical fra ct u res. Th ey a re p r im a r ily cau se d by h igh -velocit y t ra u m a in t h e you n g a n d by falls in t h e eld e rly. Od on t oid fract u res m ay ca u se at lan t oa xia l in st a b ilit y, p la cin g t h e sp in a l cord at r isk for com p ressive inju r y. Fract u res m ay resu lt in p rogressive n e u rologic d a m age or fat alit y. Th e goal of t reat m e n t is t o st ab ilize or im m ob ilize t h e at la n toa xial join t an d a ch ieve solid fu sion of t h e fra ct u re d d e n s.1 Pat ie n t s w it h a cu t e od on toid fract u re rarely p rese n t w it h seve re n e u ro logic in ju r y b u t com m on ly com p lain of a xial n e ck p ain su bse qu e n t to t rau m a . Alt h ough evid en ce-based m an agem en t recom m en dat ion s for od on toid fract u res are lackin g, p at ien t ou tcom es for t h e m ost com m on con ser vat ive an d su rgical t reat m en t s h ave been rep or ted .1 Th is ch apter d iscu sses t h e em ergen cy m an agem en t of od on toid fract u res w it h a sp eci c focu s on t h e m ost com m on ly p er for m ed t reat m en t s, in clu d in g: (1) an ter ior fu sion tech n iqu es (od on toid screw ) an d (2) p oster ior fu sion tech n iqu es (C1- C2 t ran sar t icu lar screw s; C1 lateral m ass/ C2 p ars/C2 p ed icle screw s). Con t rain d icat ion s for od on toid screw p lacem en t in clu d e od on toid fract u res w it h an an ter iorly an gled t ip fragm en t , osteop orosis, t ran sverse ligam en t d isr u pt ion , or accom p anyin g at lan toa xial fract u res. Body bu ild or in abilit y to red u ce t h e fract u re can be p roh ibit ive w it h t h is tech n iqu e. In t h ese cases, p oster ior at lan toa xial fu sion m ay be w ar ran ted .
• Disru pt ion of th e t ran sverse ligam en t cau sing atlan toa xial • •
in st abilit y. Type II odon toid fract ures w ith eviden ce of in st abilit y (i.e., greater th an 6 m m of displacem en t). Movem en t at th e fract u re site in h alo vest dem on st rated on su p in e an d u prigh t X-rays.
Preprocedure Considerations Radiographic Imaging • Radiological st u dies—in it ial lm s sh ou ld in clu de an terop os• •
•
terior, lateral, an d open -m outh odon toid view s. Com pu ted tom ography (CT) scan s w ith reform at ted im ages m ay be u sed to d eterm in e th e t ype of odon toid fract u re an d m ay p rovide m ore det ail of bony an atom y th an plain lm s. Carefu l preoperat ive review of CT im ages w ith iden t i cat ion of fract ure sites, bony an atom y, an d vertebral ar ter y course is n ecessar y to determ in e w h eth er in st rum en tat ion can be placed safely. Th e An derson an d D’Alon zo classi cat ion system , w h ich classi es fract ure t ypes I, II, an d III, is com m on ly applied (Figs. 12.1 an d 12.2; Table 12.1).2
Medication • Periop erat ive an t ibiot ics are in it iated an d m ain t ain ed for 24 h ours after in cision .
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Fig. 12.1 Commonly applied classi cation of odontoid fractures.
Table 12.1 Documented treatment options for odontoid fractures Type of odontoid fracture
Management
Reported fusion rates
Type 1
Conservative
External im m obilization
100%
Type II
Conservative
External im m obilization
55-65%
Surgical
Anterior approach, odontoid screw
Type III
90%
Posterior approach, atlantoaxial fusion or trans-articular screws
74-87%
Conservative
External im m obilization
50-84%
Surgical
Posterior approach, atlantoaxial fusion
a
100%
b Fig. 12.2a, b (a) Sagit tal and (b) coronal preoperative CT images demonstrating a t ype II odontoid fracture.
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Em ergency Managem ent of Odontoid Fractures
Operative Procedure Odontoid Screw Positioning (Fig. 12.3)
Figure
Procedural Steps
Pearls
Fig. 12.3
The patient is positioned supine on the operating table w ith the head extended in traction. The patient is intubated. Biplanar uoroscopy is used to monitor the head and dens during the procedure.
• The anteroposterior (AP) view is obtained transorally using a C-arm uoroscope, and a radiolucent prop m ay be used to open the m outh to improve AP visualization. The lateral view is obtained by a second C-arm uoroscope, oriented horizontally. Using uoroscopy as a guide, the head and neck are positioned to align the fracture edges. Finally, because blockage of screw insertion due to body obstruction (e.g., barrel chest) or body positioning (e.g., xed cervical kyphosis) m ay lim it this procedure, a Kirschner wire (K-wire) m ay be used to estim ate screw/instrum ent trajectory and ensure that the patient’s body will perm it clearance during screw placem ent prior to incision.
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Cervical Dissection and Entry Site Preparation (Fig. 12.4a–e)
a
b
182
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Em ergency Managem ent of Odontoid Fractures
c
d
e
Figure
Procedural Steps
Pearls
Fig. 12.4
(a) A transverse incision is made at approximately the C4-C5 level similar to an anterior cervical diskectomy. The platysma is incised. (b) Incision of the cervical fascia and plane is developed to the spine. (c) Dissection of the longus colli muscles. (d) Placement of radiolucent retractors. (e) The C3 body is notched and the C2-C3 ventral annulus brosis is incised.
• The spine is approached anteriorly at the C4-C5 level using ne dissection bet ween the m idline structures and carotid sheath and then blunt dissection from the longus colli m uscles to the vertebral bodies.3 Radiolucent retractors are used to perm it intraoperative uoroscopy. To prepare the screw entry site, the C3 vertebral body is notched anterosuperiorly, and the C2-C3 ventral annulus brosis is incised.
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Screw Trajectory and Placement (Fig. 12.5a, b)
a
184
b
Figure
Procedural Steps
Pearls
Fig. 12.5
(a) A K-w ire is advanced through the C2 body to establish the trajectory. (b) A single lag screw is rostrally directed through the entry site, the C2 vertebral body, and the tip of the odontoid process. This compresses the tw o bony segments together, achieving rigid internal stabilization at the fracture site.
• To establish the trajectory for screw placem ent, a drill or K-wire is advanced up through the C2 body into the m idpoint of the odontoid fragm ent. Con rm atory visualization of this pilot trajectory is achieved with uoroscopy. The drill is removed and a lag screw is advanced through the guide hole through the C2 body and through the bony cortex of the odontoid tip. Because the lag screw head is restrained by the C2 body, screw tightening pulls the odontoid fragment inferiorly, internally reducing the fracture.3,4
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Em ergency Managem ent of Odontoid Fractures
Completed Construct (Fig. 12.6a, b)
a
b
Figure
Procedural Steps
Fig. 12.6
(a) AP and (b) lateral X-ray images of nal odontoid screw construct.
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C1-C2 Transarticular Screw (Magerl Technique) Positioning (Fig. 12.7a, b)
a
186
b
Figure
Procedural Steps
Pearls
Fig. 12.7
(a) The patient is positioned prone under general anesthesia w ith the neck exed in the three -pinion head holder. (b) The screw trajectory is established w ith w ire and uoroscopy prior to prepping.
• The operating table and room should be arranged to accom m odate lateral uoroscopy with a com fortable viewing angle for the operating surgeon. A three-pinion head holder is used to secure the head in the “m ilitary tuck” position, which will allow access to the atlantoaxial joint at the appropriate angle with surgical instruments. Lateral uoroscopy can be used to con rm that no displacem ent has occurred and that the neck rem ains neutral after positioning. Screw entry sites and trajectories can be estim ated using uoroscopy at this point. In older patients with a pronounced thoracic kyphosis, an adequate trajectory may not be at tainable.
12
Em ergency Managem ent of Odontoid Fractures
Surgical Site Preparation (Fig. 12.8)
Figure
Procedural Steps
Pearls
Fig. 12.8
The area is prepped and draped in a sterile fashion to include the cervical and midthoracic spine. Three separate incisions are made : (A) midline from occiput to C4; (B, C) tw o stab incisions are made at the C7-T1 level for screw -inserting instruments.
• Three separate incisions are required: a m idline incision from the occiput to C4 to expose the C1-C2 levels and t wo stab incisions at approxim ately the C7-T1 level for instrum ent access.
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Tissue Dissection and Exposure (Fig. 12.9a, b)
a
188
b
Figure
Procedural Steps
Pearls
Fig. 12.9
(a) Tissue dissection is carried dow n through the midline along the relatively avascular midline raphe betw een the paraspinal muscles. The dissection is taken dow n to the spinous processes and articulating pro cesses of C1 and C2. (b) Brisk venous bleeding may be encountered upon exposure of the C1 facet. This should be anticipated and can be controlled w ith a thrombin-soaked gelatin sponge. The exiting C2 nerve root is encountered betw een the posterior arch of C1 and lamina of C2. It can be protected by dow nw ard retraction using a Pen eld no. 4.
• A localizing X-ray or uoroscopy can be used to con rm localization. The C2 spinous process is often bi d and m ore prom inent than the C1 or C3 spinous processes. The C1 and C2 lam inae are exposed by subperiosteal dissection with care taken to avoid disruption of the C2-C3 joint.
12
Em ergency Managem ent of Odontoid Fractures
Screw Trajectory and Placement (Fig. 12.10a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 12.10
(a) The screw entry point is typically 3 mm lateral and 3 mm superior to the inferomedial corner of the inferior articulating facet of C2. A K-w ire is used to establish the trajectory follow ed by a cannulated screw, w hich is inserted over the K-w ire. (b) The ideal trajectory (approximately 40 degrees superior to the entry site) ends at a point that overlies the shadow of the anterior C1 tubercle on lateral uoroscopy. A cannulated bit is passed over the K-w ire to create a pilot hole, w hich is tapped, and a 3.5- or 4-mm cannulated cortical screw is then advanced to the ideal target. 5
• A K-wire is advanced through the stab incision and ideal screw entry point, down the pars of C2, and across the C1-C2 joint under uoroscopic guidance. The K-wire is advanced to a point 4 m m shallow to the ideal target. The operating surgeon must be aware of the position of the K-wire at all tim es during its use to avoid inadvertent advancem ent into vital structures.
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Completed Construct (Fig. 12.11)
a
190
b
Figure
Procedural Steps
Fig. 12.11
(a) AP and (b) lateral radiographs of C1-C2 transarticular screw placement.
12
Em ergency Managem ent of Odontoid Fractures
C1-C2 Lateral Mass Fusion w ith Polyaxial Screw s and Rods Positioning and Surgical Site Preparation (Fig. 12.12)
Figure
Procedural Steps
Pearls
Fig. 12.12
The patient is positioned prone under general anesthesia under cervical traction w ith skull tongs. The incision is marked from occiput to C4. After prepping, a midline incision is made. Soft tissue dissection is conducted w ith monopolar cautery along the midline. A relatively avascular plane can be found in the midline raphe betw een the paraspinal muscles (see Fig. 12.9a).
• Intraoperative X-ray or uoroscopy is used to check alignm ent after positioning. A three-pinion head holder could also be used in lieu of traction.
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Tissue Dissection and Exposure (Fig. 12.13)
192
Figure
Procedural Steps
Pearls
Fig. 12.13
The dissection is taken dow n to the spinous processes and then to the lamina. Dissection along the inferior border of C1 lamina is performed to expose the C1 lateral mass. Epidural venous bleeding is controlled w ith gelatin sponge and cotton pledgets.
• A localizing X-ray or uoroscopy can be used to con rm localization. The C2 spinous process is often bi d and m ore prom inent than the C1 or C3 spinous processes. The C1 and C2 vertebrae are exposed by subperiosteal dissection. Bleeding from the epidural venous plexus is t ypically encountered during dissection of the C1-C2 joint. It is usually controlled with a combination of bipolar electrocautery, gelatin sponge, and cot ton pledgets.6 The lateral and m edial borders of the C1 lateral m ass are identi ed for accurate placem ent of the C1 lateral m ass screw. The C2 dorsal root ganglia can be retracted caudally to clearly view the C1 lateral m ass.
12
Em ergency Managem ent of Odontoid Fractures
C1 Screw Trajectory and Placement (Fig. 12.14)
Figure
Procedural Steps
Pearls
Fig. 12.14
The ideal screw entry point for the C1 screw is at the middle of the C1 lateral mass in the lateral-medial direction and at the midpoint betw een the inferior border of the C1 lateral mass and the junction of the posterior arch to the C1 lateral mass in the craniocaudal direction.
• The ideal screw trajectory is 10 degrees m edial and 10 degrees
•
superior (in the direction of the anterior C1 tubercle) to the entry point. The hole is tapped and a 3.5-m m screw is inserted. The screw length should be estim ated on preoperative im aging so that the screw head sits beyond the posterior arch of C1 (t ypically 30–35 m m ). Harm s and Melcher popularized this C1-lateral mass and C2-pedicle screw construct. It can also be easily m odi ed to accom m odate a C2pars interarticularis screw depending on patient anatomy. As with the transarticular approach, careful preoperative review of CT scans with identi cation of fracture sites, bony anatomy, and vertebral artery course is necessary to determ ine whether screws can be placed safely.
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C2 Screw Placement and Trajectory (Fig. 12.15)
194
Figure
Procedural Steps
Pearls
Fig. 12.15
C2 xation can be achieved w ith either a pars interarticularis or pedicle screw. (right side) The ideal entry point for a C2 pars screw is 3 mm lateral and 3 mm superior to the inferomedial corner of the C2 inferior articulating facet, similar to the C1-C2 transarticular screw. The pars screw should be aimed at a point in line w ith the middle of the C1 lateral mass in the lateral-medial direction and 40 degrees cranial to the entry site in the craniocaudal direction. (left side) The ideal entry site for a pedicle screw is 6 mm lateral and 6 mm superior to the inferomedial corner of the C2 inferior articulating facet. The ideal trajectory for the pedicle screw is 20 degrees medial and 20 degrees cranial from this point. The screw length should be measured on preoperative CT. The pilot hole should be tested w ith a ball-tip probe prior to tapping and place ment of a 3.5-mm polyaxial screw.
• The lim itations of transarticular screw placem ent and the advent of polyaxial head screws contributed to the developm ent of further C1-C2 fusion m ethods. In 2001, Harm s and Melcher popularized this novel technique of C1-C2 polyaxial screw-and-rod xation that minimizes risk to the vertebral artery, allows for intraoperative reduction of the atlantoaxial joint, and elim inates the need for supplemental bone wiring.6 The relative technical ease and improved risk pro le of this technique has m ade it the predom inant m ethod of posterior atlantoaxial fusion at the authors’ institution.7
12
Em ergency Managem ent of Odontoid Fractures
Completed Construct (Fig. 12.16)
a
b
Figure
Procedural Steps
Fig. 12.16
(a) AP and (b) lateral radiographs of nal C1-C2 xation.
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Closing • Th e w oun d is h eavily irrigated. • An opt ion al su bcu t an eou s d rain m ay be placed. • For an terior procedures, th e plat ysm a is reapproxim ated us• • •
ing 3-0 absorbable sut u res in an in terrupted fash ion . Th e paraspin al m u scles an d overlying fascia are approxim ated u sing 1-0 absorbable su t ures in an in terru pted fash ion . Th e su bcut an eou s t issues are approxim ated using 3-0 absorbable su t u res in an in terru pted fash ion . Th e w oun d is closed using 3-0 m on o lam en t nylon sut ure in a ru n n ing fash ion .
Postoperative Management Monitoring • It is th e sen ior au th or’s (JSH) p ract ice to p lace th e p at ien t in a m on itored set t ing overn igh t .
Medication • Periop erat ive an t ibiot ics are m ain t ain ed for 24 h ou rs after in cision .
Further Management • Drain s are rem oved on p ostoperat ive day 1 or 2. • Skin su t u res are rem oved after 2 w eeks. • For posterior procedures, pat ien ts are t ypically kept in a rigid •
cer vical collar for 6 to 12 w eeks after th e procedure, at w h ich poin t X-rays are taken to assess fusion . For an terior procedures, a form al sw allow evaluat ion m ay be requ ired prior to st art ing a diet becau se of th e h igh in ciden ce of postoperat ive dysph agia, par t icu larly in elderly pat ien ts.
Special Considerations The senior author (JSH) prefers not to use additional bone w iring techniques though several have been described. A posterior bone w iring technique is often perform ed to provide three-point xation. The C1-C2 transarticular screw, as initially described by Magerl in 1987, was the rst m ajor advance from bone w iring techniques.8 Using this technique, im m ediate three-dim ensional unisegm ental fusion can be achieved and, w hen perform ed in com bination w ith bone w iring techniques, the use of external im m obilization (e.g., halo vest) is not necessary. One advantage of this technique is that it elim inates rotational m otion at C1-C2, w hich increases the chance of bony fusion. However, its popularit y has been lim ited by its relative technical com plexit y and associated risks such as hypoglossal nerve and vertebral artery injuries.5 Th e basic prin ciples of m ult isystem t rau m a m an agem en t sh ou ld n ot be foregon e in th e set t ing of sp in al cord inju r y (SCI). The ABCs (air w ay, breath ing, circulat ion ) sh ould be m on itored an d t reated app ropriately. SCI p at ien t s m ay p resen t w ith oth er life th reaten ing inju ries th at m ake op erat ive in ter ven t ion for
196
atlan toaxial in st abilit y u n safe in th e acute set t ing. If th e fract ure can be reduced an d th e pat ien t does n ot h ave a progressive n eu rologic de cit th en th e p at ien t can be im m obilized in a rigid cer vical collar, h alo vest , or t ract ion un t il con curren t injuries are st abilized. In th e au th ors’ exp erien ce, p at ien ts w ith h igh cer vical injuries are best m on itored in th e in ten sive care un it un t il de n it ive t reat m en t . Th ere are no stan dards regarding th e ideal t im ing of surgical in ter ven t ion . In the on ly publish ed ran dom ized t rial on this top ic (for spin al cord inju r y pat ien ts), Vaccaro et al fou n d n o di eren ce in length of in ten sive care un it stay, length of inpat ien t reh abilit at ion , or Am erican Spin al Injur y Associat ion (ASIA) score im provem en t bet w een early (, 72 h ours from inju r y) an d late (. 5 days from inju r y) surgical in ter ven t ion in 123 pat ien t s w ith C3 to T1 injuries.9 In a recen t Coch ran e Database system at ic review, Bagnall et al foun d in su cien t eviden ce to establish recom m en dat ion s on t im ing of surger y.10 Early eviden ce from th e Surgical Treat m en t for Acute Spin al Cord Injur y St udy (STASCIS), a m ult i-inst it ut ion al ran dom ized t rial of early (, 24 h ours) versus late su rger y for isolated cer vical SCI, suggests th at early decom pression m ay be associated w ith im proved neurologic recover y at 1-year follow -up.11 Subsequen t result s dem on st rated safet y in early su rger y w ith im provem en t in at least t w o grades of the ASIA im pairm en t scale at 6 m onths’ follow -up.12
References 1. Sm ith HE, Malten fort M, Harrop JS, et al. Od on toid fract u res an d th eir m an agem en t . Top ics in Sp in al Cord Inju r y Reh abilit at ion 2010;15(3):65–72 2. An derson LD, D’Alon zo RT. Fract u res of th e odon toid process of th e axis. J Bon e Join t Su rg Am 1974;56(8):1663–1674 3. Su bach BR, Moron e MA, Haid RW Jr., McLaugh lin MR, Rodt s GR, Com ey CH. Man agem en t of acute odontoid fract ures w ith single-screw an terior xat ion . Neurosurger y 1999;45(4): 812–819; discu ssion 819–820 4. Apfelbau m RI, Lon ser RR, Veres R, Casey A. Direct an terior screw xat ion for recen t an d rem ote odontoid fract ures. J Neurosurg 2000;93(2 Su ppl):227–236 5. Haid RW Jr., Su bach BR, McLaugh lin MR, Rodt s GE Jr., Wah lig JB, Jr. C1- C2 t ran sar t icu lar screw xat ion for atlan toaxial in st abilit y: a 6-year experien ce. Neurosu rger y 2001;49(1):65–68; discu ssion 69–70 6. Harm s J, Melch er RP. Posterior C1- C2 fu sion w ith polyaxial screw an d rod xat ion . Sp in e (Ph ila Pa 1976) 2001;26(22):2467–2471 7. Sm ith HE, Vaccaro AR, Malten for t M, et al. Tren ds in su rgical m an agem en t for t ype II odon toid fract u re: 20 years of exp erien ce at a region al spin al cord injur y cen ter. Or th opedics 2008;31(7):650 8. Grob D, Magerl F. [Su rgical st abilizat ion of C1 an d C2 fract u res]. Or th op ad e 1987;16(1):46–54 9. Vaccaro AR, Daugh er t y RJ, Sh eeh an TP, et al. Neu rologic ou tcom e of early versu s late surger y for cer vical spin al cord injur y. Spin e (Ph ila Pa 1976) 1997;22(22):2609–2613 10. Bagn all AM, Jon es L, Du y S, Riem sm a RP. Sp in al xat ion su rger y for acute t raum at ic spin al cord injur y. Coch ran e Dat abase Syst Rev 2008(1):CD004725 11. Feh lings MG, Ar vin B. Th e t im ing of su rger y in pat ien t s w ith cen t ral spin al cord injur y. J Neurosurg Spin e 2009;10(1):1–2 12. Feh lings MG, Vaccaro A, Wilson JR, et al. Early versu s delayed decom pression for t raum at ic cer vical spin al cord injur y: result s of th e su rgical t im ing in acu te sp in al cord inju r y st u dy (STASCIS). PLoS On e 2012;7:e32037
13
Cervical Burst Fractures Teresa S. Purzner, Jam es G. Purzner, and Michael G. Fehlings
Introduction Cer vical burst fract ures are th e result of exion com pression inju ries an d are ch aracterized by loss in vertebral body (VB) h eigh t , cor t ical fract ure of th e posterior VB w all, ret ropulsion of fragm en t s in to th e can al, an d an in crease in in t rap edicu lar distan ce (IPD). Burst fract ures th at presen t w ith n eurologic de cit h ave p ersisten t can al com pression or th at involve th e posterior elem en t s usually require surgical in ter ven t ion —t ypically in th e form of corpectom y an d an terior recon st ruct ion . How ever, burst fract ures th at do n ot a ect th e posterior elem en t s an d presen t n eurologically in tact can be m an aged w ith extern al or th osis. In th e follow ing ch apter w e discuss the su rgical in dicat ion s, m edical m an agem en t , radiograph ic n dings, surgical ap proach , an d p ostop erat ive care of pat ien t s w ith su baxial cervical sp in e bu rst fract u res.
Indications Th ere are a variet y of classi cat ion system s for su baxial cervical bu rst fract u res. Th e Allen classi cat ion 1 categorized su baxial spin e inju ries in to six m ajor grou p s of inju r y: th ree com pressive injuries ( exion com pression [20%], exten sion com pression [25%], an d vert ical com pression ); t w o dist ract ion inju ries ( exion dist ract ion [40%], exten sion -dist ract ion ); an d n ally on e lateral exion inju r y. Bu rst fract u res belong to both exion com p ression an d vert ical com p ression categories. Perh aps th e m ost clin ically useful classi cat ion system w as put for w ard in 2007 by Vaccarro et al w h o developed th e sub axial cer vical spin e classi cat ion system (SLIC) gu idelin es (Table 13.1).2 Th ese guidelin es are u n iqu e in th eir con siderat ion of bony m orph ology, involvem en t of th e discoligam en tous com plex (DLC), an d n eurologic presen t at ion . Num erical values are given u n der each categor y dep en d ing on th e severit y of involvem ent . W h en th e sum of all th ree categories am oun ts to less th an 4 p oin t s, th en con ser vat ive m an agem en t sh ou ld be con sidered. Greater th an 4 poin t s is suggest ive of surgical m an agem en t . Based on th e SLIC scale, bu rst fract u res w ith ou t disrupt ion of th e DLC or ch ange in n eurologic st at us w ould be given 3 to 4 poin t s an d be t reated w ith extern al orth osis w h ile th ose w ith deteriorat ion in n eurologic stat us an d disrupt ion of th e DLC w ould h ave . 4 p oin ts an d th erefore requ ire su rgical stabilizat ion . Th e p roposed algorith m in clu ded in th is ch apter is also dependen t on n eu rologic stat u s an d th e st at us of th e posterior ligam en tous com plex (Fig. 13.1). Isolated burst fract ures w ith out n eurologic de cit are m an aged w ith extern al orth osis w h ile th ose presen t ing w ith n eurologic sym ptom s an d
disrupt ion of th e posterior elem en ts require both an terior decom pression an d posterior recon st ru ct ion . Panjabi an d W h ite p roposed an altern at ive p oin t-based classi cat ion system t argeted tow ard th e su baxial cer vical sp in e as w ell as th oracic an d lu m bar inju ries. Th ey con sidered angu lat ion . 11% or . 3.5 m m of sublu xat ion as un stable.3 Cooper et al based th eir decision on th e p resen ce of irred u cible facet fract u res, ret ropu lsed fragm en t s cau sing p ersisten t can al com prom ise in an in com plete SCI, progressive n eurologic de cit from sp in al in st abilit y, root decom pression , or ch ron ic progressive deform it y w ith in com p lete sp in al cord inju r y or n er ve root de cit .4 Hadley et al recom m en ded th e follow ing in dicat ion s for su rger y: irredu cible bon e align m en t , irredu cible sp in al cord com pression , in st abilit y post reduct ion , ligam en tous injur y w ith facet in st abilit y, . 15% kyph osis, or . 20% su blu xat ion .5 To bet ter determ in e th e correlat ion of radiograph ic n dings of can al com prom ise an d n eurologic outcom e, Feh lings et al perform ed an eviden ce-based an alysis of publish ed criteria in pat ien t s w ith acute cer vical SCI.6,7 Th ey w en t on to develop a prospect ive st udy invest igat ing m agn et ic reson an ce im aging
Table 13.1 SLIC guidelines Category
Points
Morphology No abnorm alit y Compression Burst Distraction Rotation/translation
0 1 2 3 4
Discoligamentous complex Intact Indeterm inate Disrupted
0 1 2
Neurologic status Intact Root injury Complete cord injury Incomplete cord injury Continuous compression
0 1 2 3 11
Note: Subaxial cervical spine injury classi cation system based on bony morphology, involvement of the discoligamentous complex, and clinical presentation. Injuries with a score of less than 4 are managed with rigid orthosis while injuries with a score of greater than 4 should be considered for surgical xation. Injuries with a score of 4 can be treated with either rigid orthosis or surgical instrumentation.
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p
u
s
j
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II Spinal Em ergency Procedures (MRI) n dings associated w ith can al com prom ise an d foun d th at m axim um spin al cord com pression as w ell as spin al cord h em orrh age an d cord sw elling w ere m ost associated w ith a poor progn osis for n eurologic recover y.8
Initial Evaluation and Medical Management Th e in it ial m an agem en t of cer vical bu rst fract ures occurs outside of th e h osp ital at th e scen e of inju r y. Th ese fract u res often occur in th e set t ing of polyt rau m a w h ere oth er life-th reaten ing inju ries can dist ract from possible n eu rologic deteriorat ion . Full cer vical spine precaut ion s w ith im m obilizat ion an d t ran sfer to an ap prop riate t rau m a cen ter sh ou ld be p erform ed e cien tly an d safely. On ce at th e t rau m a cen ter, th e Advan ced Trau m a Life Su p p or t p rotocol is in st it u ted. In th e set t ing of ret rop u lsed segm en t s an d com pressive sp in e inju r y, part icu lar at ten t ion is paid to oxygen at ion an d m ain ten an ce of adequ ate p erfu sion . St rict blood pressu re con t rol is im port an t w ith a t arget m ean arterial pressure (MAP) above 80. Hypoten sion can in it ially be m an aged w ith uid boluses; h ow ever, in it iat ion of vasopressors sh ould be con sidered if adequate perfusion is n ot ach ieved w ith uid boluses alon e. Th e role of steroids rem ain s am biguous an d is w ell review ed elsew h ere. On ce th e p at ien t is st abilized , a th orough h istor y can reveal th e m ech an ism of injur y an d t im ing of n eurologic deteriorat ion . Cer vical exion com p ression injuries are p ar t icu larly con cern ing for bu rst fract u res. Follow ing th e prim ar y sur vey, a th orough physical exam is requ ired. In it ial in spect ion an d palpat ion can iden t ify obvious deform it ies, extern al soft t issue injuries, an d local areas of ten dern ess or asym m et r y. W h en a h istor y is n ot available, pat tern s of injuries can som et im es suggest th e m ech an ism of injur y. Next , a dedicated n eu rologic exam sh ould focus on lim b st rength , sen sat ion an d re exes, t run cal sen sat ion , an d perspirat ion as w ell as bow el an d bladder sph in cter fun ct ion . Th e Am erican Spin al Injur y Associat ion classi cat ion system (ASIA) is a com m on clin ical classi cat ion system th at allow s for an organ ized ap proach to th e n eu rologic exam an d categorizes degree of injur y in to four groups.9 ASIA A inju ries are com p lete SCIs w h ere n o sen sor y or m otor fu n ct ion is p reser ved. ASIA E inju ries h ave n o m otor or sen sor y de cit . ASIA B to D injuries are in com plete SCIs w h ere sen sory fu n ct ion is p reser ved bu t w ith var ying degrees of loss in m otor fun ct ion . Im port an tly, ongoing progression of n eurologic de cit s can suggest ongoing or progressive com pression w h ether by un st able or ret ropulsed fract u re fragm en t s or an expan ding h em atom a. Th ese are im port an t to iden t ify early as t im ely decom pression can h ave sign i can t im p act on overall ou tcom e. Early opt im izat ion of m edical m an agem en t h as been sh ow n to ben e t long-term p rogn osis; h ow ever, th e t im ing of su rgical in ter ven t ion rem ain s som ew h at m ore con t roversial. Th ere exist s a large body of literat u re invest igat ing th e role of early surgical in ter ven t ion . Th e best eviden ce to date w as pu t for w ard by Feh lings et al in th e Su rgical Tim ing in Acu te Spin al Cord Injur y St u dy (STASCIS t rial).10 Th is in tern at ion al m ult icen ter prospect ive coh ort st udy looked at 313 pat ien t s w ith acute cer vical SCI. Of th ese, 182 u n der w en t early su rger y (w ith in 24 h ou rs) an d 131 un der w en t late surger y (after 24 h ours). Prim ar y ou tcom e w as ch ange in ASIA Im p airm en t Scale (AIS) grade at 6 m on th s.
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Secon dar y ou tcom es w ere rates of com plicat ion an d m or talit y. Tw en t y percen t of pat ien t s un dergoing early su rger y sh ow ed a 2 grade im provem en t com pared to 8.8% in th e late decom pression group. Mort alit y an d rates of com plicat ion w ere n ot st at ist ically sign i can t bet w een th e t w o grou p s. Th is st u dy w ou ld suggest th at decom p ression w ith in 24 h ou rs is ben e cial. Closed redu ct ion , if at tem pted, is a relat ively w ell-tolerated procedure w ith an overall reduct ion rate of approxim ately 80%, 30% recurren t displacem en t or m alalign m en t , 2 to 4% chan ce of t ran sien t de cit , an d 1% ch an ce of perm an en t de cit . Overall rates of failu re in com pression fract u res of th e su ba xial C-spin e w ere fou n d to be aroun d 5%. Sim ilarly, Koivikko et al fou n d a rate of reop erat ion in p at ien t s t reated w ith orth osis to be 4%(com pared to 3%in surgically m an aged pat ien ts).11 W h ile n on surgical m an agem en t is cert ain ly th e appropriate decision in a large percen tage of pat ien ts, th ere is som e eviden ce th at n eu rologic im p rovem en t , kyp h ot ic deform it y, an d can al sten osis w ere all im p roved in pat ien t s t reated su rgically.11 Most st u dies, h ow ever, w ere ret rospect ive review s an d outcom es w ere gen eralized to a sp ect ru m of fract u re p at tern s. Furth erm ore, th e di eren ces in recover y bet w een surgical an d non surgical m an agem en t is far ou t w eigh ed by th e stat u s at presen t at ion th an ch oice of t reat m en t . Pat ien ts w h o are t reated w ith a h alo vest or h ard cer vicoth oracic orth osis for 2 to 3 m on th s sh ou ld be follow ed up w ith exion -exten sion X-rays to h elp determ in e su ccess of fu sion .
Preprocedure Considerations Radiographic Imaging • Th e ch oice of im aging in su spected cer vical burst fract ures
•
•
h as ch anged over th e past few decades. Tradit ion ally, an teroposterior (AP), lateral, an d odon toid plain lm s of th e C-spin e w ere th e rst-lin e im aging of choice. Th ere are several radiograp h ic feat u res suggest ive of bu rst fract u res—m ost im port an tly, loss of ver tebral body h eigh t , cort ical fract ure of th e posterior VB w all, ret ropu lsion of fragm en t s in to th e can al result ing in loss of th e dorsal ver tebral body lin e, an d an in crease in in t rapedicu lar distan ces or sp laying of th e facet join t s. Th is is occasion ally accom pan ied by VB kyph ot ic or t ran slat ion al deform it y. In m any cen ters, com p u ted tom ography (CT) scan is n ow th e rst-lin e im aging m odalit y of ch oice in cases su sp iciou s of n eck t rau m a. Typ ically, bu rst fract u res w ill h ave d isru pt ion of th e posterior VB w all w ith or w ith ou t ret ropulsed fragm en t s. As in plain lm s, th ey w ill dem on st rate an in creased IPD w ith splaying of th e vertebral arch . CT angiograp hy (CTA) sh ou ld also be con sidered w h en th ere is con cern of com p rom ise of th e ver tebral can al an d, in m any in st it ut ion s, it h as becom e part of th e st an dard im aging protocol for con rm ed C-spin e inju ries. MRI can often be h elp fu l in bet ter visu alizing soft t issu e st ru ct u res, disk, can al sten osis as w ell as cerebrospin al u id (CSF) e acem en t , cord im pingem en t , or sign al ch anges—23% of all blu n t t raum a pat ien t s presen t ing w ith a cer vical in jur y h ave eviden ce of disk injur y on MRI. Th is in creases to as h igh as 36% of th ose p at ien ts w ith com p lete SCI, 54% of
13
•
in com p lete SCI, an d 47% of p at ien t s w ith u n st able SCI.12 MRI sh ou ld be p erform ed in a t im ely m an n er, part icu larly w h en th e clin ical exam is n ot explain ed by radiograph ic n dings. In th ose pat ien t s w ith equivocal exam or radiograph ic n dings, 15.5% h ave been fou n d to h ave both disk an d ligam entous disrupt ion , w h ile 20% h ave isolated ligam en tous abn orm alit y.13 T1-w eigh ted im ages are useful for th eir en h an cem en t of subacute h em orrh age w h ile T2 w eigh ted im ages w ill sh ow hyperin ten sit y at areas of edem a. Sh or t inversion recover y (STIR) im aging is a fat suppression sequ en ce th at is part icularly h elpful in h igh ligh t ing areas of ligam en tous injur y. Gradien t ech o im aging an d su scept ibilit y-w eigh ted im aging w ill fur th er evaluate th e presen ce of h em orrh age. Di u sion w eigh ted im aging (DW I) u ses rap id ech o p lan ar sequ en ces to h igh ligh t acu te isch em ic even t s. It h as been u sed ver y su ccessfully in evaluat ing t rau m at ic brain injur y an d cerebral isch em ia bu t is st ill lim ited in th e spin al cord given th e cardiorespirator y m ot ion ar t ifact , CSF pulsat ion , an d th e sm aller region of in terest . Non eth eless, it is an area of act ive research th at h as been sh ow ing prom ising prelim in ar y results. MRI sh ould be st rongly con sid ered in th e set t ing of bu rst fract u res p ar t icularly w h en th ere is con cern of a t rau m at ic disk prot ru sion or to assess th e degree of can al sten osis resu lt an t from ret rop ulsion of th e posterior elem en ts. Eith er of th ese w ou ld be im port an t in surgical plan n ing. Preoperat ive im aging (Fig. 13.2).
Approach On ce th e decision to operate h as been m ade, th e role of an terior, posterior, or com bined approaches m ust be con sidered. There are risks an d ben e ts to both an d approach is ult im ately determ in ed by th e areas of com pression , n eurologic stat u s, stat us of the posterior elem en ts, an d com fort of th e surgeon. In cer vical burst fract ures the approach of choice is predom inantly ventral. Neurologic com pression is a result of retropu lsed an terior elem en ts w h ich can be rem oved un der direct vision w ith an an terior approach and therefore on e can provide opt im al decom pression . Fu rth erm ore, corpectom y w ith an terior recon st ruction provides excellent biom echanical stabilit y and correction of kyphotic deform it ies. The resected vertebral body provides large am oun ts of excellen t m aterial for autologous bon e graft ing. An terior approach es also h ave less blood loss an d postoperat ive pain. Indeed, w hen directly com pared, Toh et al found an terior fusion preferred to posterior fusion in cer vical burst and teardrop fract ures.14 This w as echoed by several biom echanical
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st udies looking at th e stabilit y of th e cer vical spin e after an terior fu sion , posterior fusion , an d com bin ed fusion s in pat ien ts w ith VB fract ures. It w as found th at alth ough posterior fusions w ere stronger th an an terior fusion s both w ere stronger th an th e intact spine. This w as true in both isolated anterior injur y or com bined anterior/posterior injuries. Therefore, particularly in the set t ing of in tact posterior elem en ts, th e role of corpectom y w ith an terior recon struct ion provides adequate stabilizat ion for longterm bony fusion. Nonunion rate is approxim ately 3%.15 More exten sive recon st ru ct ion s, involving com bin ed an terior an d p osterior app roach es, are n ecessar y in cases w ith su bopt im al bon e qu alit y, involvem en t of th e posterior elem en t s, or existing long fused segm en ts. Bon e m in eral den sit y h as a sign i cant im pact on overall fu sion rates 16 an d th e degree of fu sion m u st be t ailored to both th e den sit y of h ealthy bon e an d degree of bony disrupt ion . Gen erally, at least th e caudal th ird of th e caudal vertebral body an d caudal endplate of th e rost ral vertebral body sh ou ld be in tact for appropriate fusion . Com bined an terior an d posterior fu sion is u sed in p at ien t s w ith ver y st i or spon dylot ic spin es (di use idiopath ic skeletal hyperostosis [DISH], an kylosing spon dylit is) or in th e set t ing of injur y to th e posterior elem en ts. Com bin ed operation s h ave been sh ow n to provide im m ediate rigid st abilizat ion , increased fusion , an d decreased rates of ven t ral plate failu re. Par t icularly w h en both can be perform ed un der a single an esthet ic, a com bin ed approach can avoid th e requirem en t of postoperat ive h alo xat ion in com plex spin al injuries. Isolated posterior approach es are t ypically con sidered in th e set t ing of facet fract u res or dislocat ion s w ith en dplate disru pt ion w ith out sign i can t com pression or disru pt ion of th e vertebral body. Posterior approach es are usefu l w h en pat ien t s h ave failed closed red u ct ion an d th ere is su spicion th at in t raoperat ive reduct ion w ill be di cult .
Operative Field Preparation Fiberopt ic in t ubat ion w h ile th e pat ien t is asleep is recom m en ded in all u n stable cer vical bu rst fract u res w h en p ossible. Povidin e iodin e or ch lorh exidin e is applied to th e surgical site an d allow ed to dr y for 3 m in u tes. Th e u se of p reop erat ive local an esth et ic is u p to th e d iscret ion of th e su rgeon ; t yp ically th e m arked in cision is in lt rated w ith 1% lidocain e w ith ep in ep h rin e 1:100,000. Prophylact ic an t ibiot ics sh ou ld be given an d dexam eth ason e sh ou ld be con sidered p art icu larly in th e set t ing of cord com p ression or n eurologic com prom ise.
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a
c
b
d
Fig. 13.2 These lms (a, b) depict a patient with a C4 “tear drop” fracture of the vertebral body (c, d) that was associated with posterior C4-5 facet and laminar disruption.
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Operative Procedure Positioning (Fig. 13.3)
Figure
Procedural Steps
Pearls
Fig. 13.3
The patient is positioned supine w ith the face midline. A small bolster is placed betw een the scapula and the neck is put in general extension w ith the occiput resting on a donut. Shoulders are taped dow n.
• Right-handed surgeons tend to prefer right-handed incisions, while the opposite is true with left-handed surgeons. Anatom ically, the recurrent laryngeal nerve runs a less predictable course on the right-hand side while the thoracic duct is a unilateral structure found only on the lefthand side. Previous surgery is a relative indication to approach from the ipsilateral side given the potential for bilateral vocal cord paralysis in the set ting of bilateral anterior cervical approaches.
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Incision and Subplatysmal Dissection and Identi cation of Omohyoid (Fig. 13.4)
Figure
Procedural Steps
Fig. 13.4
A right longitudinal paracervical incision is made w ith a no. 20 blade along the anterior border of the sternocleidomastoid muscle. The incision is extended dow n through skin, subcutaneous tissue, and platysma. Subplatysmal aps are elevated and the omohyoid muscle is isolated and divided w ith diathermy cautery.
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Identi cation of the Deep Cervical Investing Fascia (Fig. 13.5)
Figure
Procedural Steps
Pearls
Fig. 13.5
The carotid triangle is entered betw een the carotid sheath and the pretracheal fascia by exploiting the avascular planes of the deep cervical investing fascia.
• Through the superior end of incision, the superior thyroid artery and superior laryngeal nerve can be identi ed and protected. At the lower end of the incision the inferior thyroid vein can occasionally be visualized. At all points it is important to identify and protect the pharynx/esophagus.
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Identi cation of the Prevertebral Fascia (Fig. 13.6)
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Figure
Procedural Steps
Fig. 13.6
Blunt dissection is used to identify the prevertebral fascia w hich is then opened w ith sharp dissection. Superior osteal dissection ensues under the longus colli muscle bilaterally.
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Cervical Burst Fractures
Placement of Self-retaining Retractors (Fig. 13.7)
Figure
Procedural Steps
Pearls
Fig. 13.7
Retractors are positioned to displace esophagus, trachea, and strap muscles medially. The carotid, internal jugular, and sternocleidomastoid muscle are retracted laterally.
• Retractors should be interm it tently released to m inim ize pressure on the soft tissues. In addition, the endotracheal cu can be de ated to m inim ize pressure on the tracheoesophageal groove and thereby decrease the risk of injury to the recurrent laryngeal nerve.
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Diskectomy (Fig. 13.8)
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Figure
Procedural Steps
Fig. 13.8
Disk spaces above and below the injured vertebra are evacuated using a combination of high speed bur, pituitary rongeurs, Kerrison punches, and microsurgical curettes. A longitudinal trough is then fashioned longitudinally in line w ith the uncovertebral joints. The endplates are thoroughly burred dow n to posterior longitudinal ligament.
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Cervical Burst Fractures
Corpectomy (Fig. 13.9)
Figure
Procedural Steps
Fig. 13.9
The injured vertebral body is resected w ith Leksell rongeurs and high-speed burs. The posterior longitudinal ligament is then opened and all retropulsed fragments are carefully removed via microsurgical dissection under microscopic magni cation.
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Placement of Allograft (Fig. 13.10)
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Figure
Procedural Steps
Fig. 13.10
Distraction pins are placed in the vertebral body above and below the level of injury. Fibular allograft is cut to the appropriate length and packed w ith local corpectomy bone graft. These are gently tapped in to position. Distraction pins are removed and the security of t is assessed. Bleeding from the pin sites is controlled w ith bone w ax.
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Cervical Burst Fractures
Placement of Anterior Locking Plate (Fig. 13.11)
Figure
Procedural Steps
Pearls
Fig. 13.11
Calipers are used to assess the length of bony defect and an anterior locking plate is chosen. Four 14-mm locking screw s are used to xate the plate.
• The literature supporting dynamic or static locking plates is divergent 17 and the decision to use one over the other is typically related to the preference of the surgeon. While locking screws do have bene t over nonlocking screws,18,19 unicortical and bicortical screws have both shown immediate stability so either is a reasonable choices depending on the experience of the surgeon and risk of protrusion through the posterior vertebral bodies.20 Approximately 4 mm should be left at both the rostral and caudal end to diminish the risk of future adjacent level disease.
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Closing • Ret ractors are rem oved an d soft t issues are carefu lly in spect -
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ed for bleeding. Hem ostasis is m et icu lou sly ch ecked an d secu red . Jackson -Prat t drain can be p laced in th e prevertebral space an d extern alized th rough sep arate st ab in cision an d con n ected to th e bulb suct ion . Th e w oun d is repaired in layers using 2-0 braided absorbable su t u re for su bcu t an eou s t issu e an d sim ilar 4-0 su bcu t icu lar for skin .
Postoperative Management Monitoring • Pat ien t s sh ou ld be m on itored for blood pressu re an d n eurologic fu n ct ion postoperat ively w ith a t arget of MAP . 80. A p lain CT of th e cer vical sp in e w ill h elp con rm p lacem en t of in st rum en t at ion .
Medication • Th e u se of postoperat ive an t ibiot ics is con t roversial. Th ere is •
n o good evid en ce th at rou t ing postoperat ive an t ibiot ics provides any advan t age to p ostop w ou n d in fect ion s. The use of steroids in acute SCI is also controversial and its poten tial ben e t m ust be w eigh ed again st th e risk of pn eu m on ia, poor w ound healing, and recover y from associated injuries.
Radiographic Imaging (Fig. 13.12)
Fig. 13.12 The patient was treated with a C4 corpectomy and C3-5 anterior reconstruction with a bular allograft (packed with local corticocancellous autograft), and anterior screw-plate xation. Under the same anesthetic, the patient was turned (using May eld cranial xation and a Jackson table) in the supine position and a C3-5 posterior lateral mass reconstruction was undertaken.
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Further Management • Dep en ding on th e degree of inju r y, u se of an extern al or th osis postoperat ively m ay ben e t th e pat ien t in term s of both stabilit y an d pain con t rol.
Special Considerations Th e term “cer vical burst fract ure” is used in a variet y of con text s. Th e im port an t factors in determ in ing th e role of su rgical xat ion are th e involvem en t of th e posterior com plex an d ongoing n eurologic de cit secon dar y to ongoing cord com pression . Th ey are often con sidered in th e con text of su baxial cer vical spin e classi cat ion system s, m ost n ot ably th e SLIC classi cat ion . W h ile th ese can aid in determ in ing th e st abilit y of th e injur y, ult im ately each pat ien t an d th eir inju r y is un iqu e an d requ ire in dividu al con sid erat ion .
References 1. Allen BL, Jr., Fergu son RL, Leh m an n TR, O’Brien RP. A m ech an ist ic classi cat ion of closed, in direct fract ures an d dislocat ions of th e low er cer vical spin e. Spin e (Ph ila Pa 1976 ) 1982;7(1):1–27 2. Vaccaro AR, Hu lber t RJ, Patel AA, et al. Th e su baxial cer vical spin e injur y classi cat ion system : a n ovel approach to recogn ize th e im por t an ce of m orph ology, n eurology, an d integrit y of th e disco-ligam en tou s com p lex. Sp in e (Ph ila Pa 1976 ) 2007;32(21): 2365–2374 3. W h ite AA, III, Panjabi MM. Update on th e evalu at ion of in st abilit y of th e low er cer vical spine. In st r Cou rse Lect 1987;36: 513–520 4. Coop er PR, Maravilla KR, Sklar FH, Moody SF, Clark W K. Halo im m obilizat ion of cer vical spin e fract u res. In dicat ions an d result s. J Neu rosu rg 1979;50(5):603–610 5. Hadley MN, Walters BC, Grabb PA, et al. Gu idelin es for th e m an agem en t of acu te cer vical sp in e an d sp in al cord inju ries. Clin Neurosu rg 2002;49:407–498 6. Feh lings MG, Rao SC, Tator CH, et al. Th e opt im al rad iologic m et h od for assessing sp in al can al com p rom ise an d cord com p ression in p at ien t s w it h cer vical sp in al cord inju r y. Par t II: Resu lt s of a m u lt icen ter st u dy. Sp in e (Ph ila Pa 1976) 1999;24(6):605–613 7. Rao SC, Feh lings MG. Th e opt im al radiologic m eth od for assessing spin al can al com prom ise an d cord com pression in pat ien t s w ith cer vical spin al cord injur y. Par t I: An eviden ce-based analysis of th e publish ed literat ure. Spin e (Ph ila Pa 1976 ) 1999;24(6): 598–604 8. Miyanji F, Fu rlan JC, Aarabi B, Arn old PM, Feh lings MG. Acu te cer vical t raum at ic spin al cord injur y: MR im aging n dings correlated w ith n eurologic outcom e—prospect ive st udy w ith 100 con secut ive pat ien t s. Radiology 2007;243(3):820–827 9. Marin o RJ, Barros T, Biering-Soren sen F, et al. In tern at ion al st an dards for n eurological classi cat ion of spin al cord injur y. J Spin al Cord Med 2003;26 Su p pl 1:S50–S56 10. Feh lings MG, Vaccaro A, Wilson JR, et al. Early versu s delayed decom pression for t rau m at ic cer vical spin al cord injur y: result s of th e Su rgical Tim ing in Acu te Spin al Cord Inju r y St u dy (STASCIS). PLoS On e 2012;7(2):e32037
13 11. Koivikko MP, Myllyn en P, Karjalain en M, Vorn an en M, San t avir t a S. Con ser vat ive an d operat ive t reat m en t in cer vical burst fract ures. Arch Or th op Traum a Surg 2000;120(7-8):448–451 12. Rizzolo SJ, Vaccaro AR, Cotler JM. Cer vical sp in e t rau m a. Sp in e (Ph ila Pa 1976 ) 1994;19(20):2288–2298 13. Benzel EC, Hart BL, Ball PA, Baldw in NG, Orrison W W, Espinosa MC. Magnetic resonance im aging for the evaluation of patients w ith occult cervical spine injur y. J Neurosurg 1996;85(5):824–829 14. Toh E, Nom u ra T, Wat an abe M, Moch ida J. Su rgical t reat m en t for inju ries of th e m iddle and low er cer vical spin e. Int Or th op 2006;30(1):54–58 15. Zigler J, Eism on t F, Gar n S, Vaccaro A. Sp in e Trau m a. Rosem on t , IL: Am erican Academ y of Or th opaedic Su rgeon s; 2011 16. Dvorak MF, Pit zen T, Zh u Q, Gordon JD, Fish er CG, Oxlan d TR. An terior cer vical plate xat ion : a biom echan ical st u dy to evaluate
17.
18.
19.
20.
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th e e ect s of p late d esign , en dp late p rep arat ion , an d bon e m in eral den sit y. Spin e (Ph ila Pa 1976 ) 2005;30(3):294–301 Leh m an n W, Briem D, Blauth M, Sch m idt U. Biom ech an ical com parison of anterior cer vical spin e locked an d u n locked platexat ion system s. Eur Spin e J 2005;14(3):243–249 Spivak JM, Ch en D, Ku m m er FJ. Th e e ect of locking xat ion screw s on th e st abilit y of an terior cer vical plat ing. Spin e (Ph ila Pa 1976 ) 1999;24(4):334–338 DuBois CM, Bolt PM, Todd AG, Gupt a P, Wet zel FT, Ph illips FM. St at ic versus dyn am ic plat ing for m ult ilevel an terior cer vical discectom y an d fusion . Spine J 2007;7(2):188–193 Leh m an n W, Blauth M, Briem D, Sch m idt U. Biom echan ical an alysis of anterior cer vical spine plate xat ion system s w ith un icort ical an d bicor t ical screw purch ase. Eur Spin e J 2004; 13(1):69–75
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Cervical Facet Dislocation Daniel Resnick and Casey Madura
Introduction Dislocat ion of th e facets join t s of th e spin e can occu r at all levels, but it is m ost com m on ly an injur y fou n d in th e cer vical spin e. First , th e coron al orien t at ion of th e join t s th em selves leaves th em suscept ible to dislocat ion w ith hyper exion . Secon d, un like th e su bstan t ial size of th e lum bar ar t icu lat ing processes, th ose in th e cer vical spin e are m uch less robust .1 Th erefore, th e ar t iculat ing processes in th e cer vical spin e are m uch m ore p ron e to fract u re an d dislocat ion . Th ird , th e cer vical spin e is n at u rally h igh ly m obile in com p arison to th e th oracic an d lu m bar spin e w ith th e h ead’s w eigh t ser ving as a con t ribut ing factor. Th is ch aracterist ic leaves th e cer vical spin e vuln erable to su dden ch anges in m ovem en t su ch as th at w h ich occu rs in a h ead-on collision . Dislocat ion of th e cer vical facet join ts can be both u n ilateral an d bilateral. In th e case of u n ilateral facet dislocat ion , th ere is often a rotator y force experien ced along w ith th e hyper exion . Th e hyp er exion force vector is en ough to raise th e in ferior ar t icu lat ing processes of both facet join ts at th e a ected level w ith respect to th e superior ar t iculat ing process. The rotat ion exp erien ced at th e sam e t im e cau ses on ly on e of th e t w o elevated in ferior art icu lat ing p rocesses to t ran slate for w ard, locking an terior to th e su perior art icu lat ing p rocess of th e ver tebra below it .2 A pu rely hyp er exion m om en t w ith ou t rot at ion is m u ch m ore likely to cau se bilateral facet dislocat ion as th e force vectors exp erien ced by each facet are th eoret ically sim ilar. In eith er scen ario, th e dislocat ion is visu alized as eith er a p erch ed facet (on e in w h ich th e in ferior p roject ion of th e in ferior ar t icu lat ing p rocess of th e p roxim al ver tebral body ar t iculates w ith th e superior project ion of th e superior ar t icu lat ing process of th e dist al ver tebral body) or a locked facet (in w h ich th e in ferior art icu lat ing process of th e p roxim al ver tebral body is an terior to th e su perior art iculat ing process of th e dist al ver tebral body). All region s of th e cer vical spin e are n ot created equ al. Un like th e su baxial cer vical spin e, th e C1-C2 facet join t s are orien ted in an axial plan e m aking th em less vuln erable to dislocat ion from hyper exion . Th e occip itocer vical ju n ct ion is su bject to a n u m ber of part icu lar inju r y pat tern s th at are discu ssed elsew h ere. It is th e su baxial cer vical spin e, speci cally C4- C7, th at is m ost p ron e to hyper exion inju ries.3 In large p art , th is is du e to th e dyn am ic forces th e cer vical spin e experien ces as a collision evolves. At th e on set of a h ead -on collision , th e low er cer vicoth oracic jun ct ion of th e spin e com presses an d extends w h ile th e subaxial cer vical spin e exes w ith great force. As th e forces evolve, th e cer vical sp in e is even t u ally th row n in to exten sion . Th is evolut ion of forces, com m on ly referred to as w h iplash , causes th e spin e to assum e an S-shape, a ph en om en on referred to as “sn aking.” Th e hyper exion , if severe en ough , can lead to facet dislocat ion by it self.
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In rear end collisions, th e dam age can be even m ore severe. Initially, the victim ’s neck m ay hyperextend, forcing the inferior articulating process dow n in to the superior articulating process. If the articular surface fails, fracture of the inferior articulating process can occur, weakening the facet joint as a w hole. The inevitable hyper exion that follow s then causes the dislocation, unhindered by the norm al ligam entous and joint capsule restraints. The ultim ate result of any facet dislocation in the cervical spine is an unstable spine that requires im m ediate treatm ent. Treatm ent options include nonoperative m anagem ent w ith closed reduction followed by im m obilization in an external xation device such as a halo vest or Minerva brace versus operative xation follow ing either closed or open reduction. The details of the di erent op tions are discussed below, but there is a general agreem ent that the universal presence of ligam entous injury in facet dislocations m akes operative xation a preferred technique for treatm ent of both unilateral and bilateral facet dislocations of the cervical spine.
Indications • Hyp er exion inju r y resu lt ing in u n ilateral or bilateral facet •
•
•
dislocat ion such as a h ead-on m otor veh icle collision . Com bin ed hyperexten sion /hyper exion injur y result ing rst in facet fract ure due to hyperexten sion w ith su bsequen t facet dislocat ion due to hyper exion as is experien ced during a severe rear-en d collision . If th e exam in at ion reveals n o n eu rologic de cit or a com p lete sp in al cord inju r y, su rgical st abilizat ion sh ou ld occu r as soon as th e p at ien t is m edically st able an d an ap p rop riate team is available. If th e exam in at ion reveals n dings con sisten t w ith a p art ial sp in al cord inju r y, u rgen t redu ct ion an d st abilizat ion is recom m en ded as soon as th e pat ien t is h em odyn am ically st able. Hyp oten sion sh ou ld be avoid ed in all p at ien ts, esp ecially th ose w ith n eurologic de cits.
Examination • Any pat ien t th at su ers a cer vical facet dislocat ion h as su s-
• •
t ain ed forces su cien t to cause a m yriad of oth er life-th reat en ing inju ries; th erefore, a fu ll t rau m a w orku p sh ou ld be com pleted w ith priorit y given to th e ABCs (air w ay, breath ing, circulat ion ). Im m obilizat ion of th e cer vical spin e du ring th is evalu at ion m u st be a priorit y. A full n eurologic exam in at ion sh ould be perform ed as th is h as im plicat ion s regarding th e t im ing of in ter ven t ion . Ad dit ion ally, evalu at ion of n eu rologic st at u s m ay allow localizat ion of th e injur y prior to im aging.
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Reduction—Closed or Open
4
Guidelines,6 Hurlburt,7 NASCIS I8 an d II9 as w ell as subsequen t publications,10 the standard at our in stit ution is to not adm in ister steroids.
• Class III eviden ce suggest s early redu ct ion of cer vical facet •
•
• • • •
fract u re/d islocat ion m ay be associated w ith im p roved n eu rologic ou tcom e. If th e p at ien t is aw ake, th is can be perform ed w ith m ild sedat ion .5 If th e pat ien t is un respon sive or u nable to cooperate, m agn et ic reson an ce im aging (MRI) is in dicated prior to redu ct ion as th e n eu rologic exam in at ion can n ot be follow ed an d th e p resen ce of a large ven t ral lesion m ay be a relat ive in dicat ion for an open redu ct ion via an an terior approach . Closed redu ct ion tech n ique in cludes h alo or tongs t ract ion , w h ich is discu ssed in Ch apter 11. Closed reduct ion an d extern al bracing is associated w ith in creased m orbidit y an d m ort alit y related to prolonged bedrest . Su ccess of closed redu ct ion is 80%. Risk of su ering ad dit ion al p erm an en t n eu rologic inju r y du ring closed reduct ion is , 1%. Risk of su ering addit ion al t ran sien t n eu rologic inju r y du ring closed reduct ion is 2 to 4%. If reduction fails, the likelihood of other injuries such as facet fracture or herniated disks is increased. This necessitates further im aging studies such as MRI prior to open reduction to determ ine the initial direction of approach (anterior versus posterior).
Cervical Facet Dislocation
Operative Management 11 Approach • If closed redu ct ion h as been ach ieved, an terior xat ion an d
•
fu sion , p osterior xat ion an d fu sion , or h alo im m obilizat ion are t reat m en t opt ion s. In gen eral, h alo im m obilizat ion is associated w ith a relat ively h igh failu re rate an d th e vast m ajorit y of su rgeon s w ill o er a direct xat ion p rocedu re. If th e dislocat ion requ ires op en redu ct ion , th e su rgeon m ay ch oose bet w een an terior or posterior approach es depen ding on th e an atom y of th e injur y an d th e experien ce of th e su rgeon . Th e p resen ce of a large ven t ral disk h ern iat ion m ay be a relat ive in dicat ion for an an terior approach as a kn ow n u n ilateral ver tebral arter y inju r y. In th ese cases, th e use of MRI is app ropriate. If th e dislocat ion is com p lete en ough th at th e surgeon does n ot believe an an terior approach feasible for reduct ion , th en a posterior approach is in dicated.
Techniques
Preprocedure Considerations Radiographic Imaging
• Opt ion s in clu de: an terior fu sion w ith or w ith ou t p late xa•
• Com puted tom ography (CT) scan: CT is the workhorse of cervi-
•
•
cal spine traum a evaluation. Identi cation of osseus abnorm alit y is straightforward w hile ligam entous injury is not always detectable. Ligam entous injury m ay be detected due to enlarged spaces bet ween otherw ise norm al appearing osseus structures. MRI: Th is test h as, in th e past , been advocated as a n ecessar y p ar t of any pre-reduct ion w orkup, w h eth er th at reduct ion be in th e in ten sive care un it (ICU) or operat ing room set t ing. Th e rat ion ale for th is w as to iden t ify any ven t ral in ter vertebral disk h ern iat ion s th at m ay cause n eurologic injur y du ring reduct ion . According to an eviden ce-based review, th ere w as n o relat ion sh ip bet w een th e p resen ce of h ern iated disks an d risk of n eu rologic inju r y du ring closed redu ct ion of facet dislocat ion s in th e presen ce of a ven t rally h ern iated disk.4 W h ile p re-redu ct ion or preop erat ive MRI m ay be useful in term s of de n ing associated injuries an d in som e cases dict at ing surgical approach , as in th e obt un ded pat ien t , in th e absence of a clear in dicat ion for MRI, reduct ion of th e dislocat ion sh ould n ot be delayed in a p at ien t w ith a severe n eu rologic inju r y. Cervical X-ray: The role of plain radiographs in the initial assessm ent of severe traum a has been lim ited by the advent of aggressive use of CT im aging. Plain lm s are quite helpful for diagnosing cervical facet dislocations and are em ployed serially (or w ith uoroscopy) during the process of either open or closed reduction.
•
•
t ion , posterior fusion an d w iring, an d posterior fusion w ith lateral m ass p late, rod, clam p, or cable xat ion . Posterior fusion w ith lateral m ass plate, rod, clam p, or cable xat ion p rovides in st an t stabilit y (allow ing early m obilizat ion of th e pat ien t). Ch oice of tech n iqu e is based on th e in tegrit y of th e bony st ru ct u res an d th e exp erien ce of th e su rgeon . Posterior fu sion w ith w iring m ay also be associated w ith an in creased risk of late kyph ot ic angulat ion com p ared to m ore rigid tech n iqu es. In on e st u dy, 22 of 165 pat ien t s w ith cer vical facet dislocat ion t reated via posterior fusion an d w iring developed kyph osis com pared to just 1 of 40 pat ien t s t reated via p osterior fu sion an d lateral m ass xat ion .11 Anterior fusion w ithout plating is associated w ith a h igh er in ciden ce of graft displacem ent and late developm en t of kyph osis th an posterior fusion w ith xat ion. Six of 101 pat ient s t reated in th is fash ion developed late instabilit y com pared to 6 of 237 pat ients t reated via a posterior fusion w ith lateral m ass xat ion .11 Th e use of an terior fu sion w ith plate xation is w ell described an d is associated w ith excellen t outcom es.12–16
Operative Field Preparation • Cer vical im m obilizat ion m ust be m ain t ain ed at all t im es. ◦ With regards to anesthesia, the inherent instability of this ◦ ◦
Medication
◦
• Steroids: Methylprednisolone for spinal cord injur y is a topic of
◦
great con troversy. Draw ing from the 2002 an d 2013 AANS/CNS
t ype of spinal colum n injury encourages beroptic intubation. Regardless of th e n al posit ion (pron e or su pin e), th e n eck sh ou ld be kept in a n eu t ral p osit ion at all t im es. Th e operat ive area is cleared of h air u sing clippers on ly an d clean sed w ith alcoh ol. Povidin e iodin e or ch lorh exidin e prep is used to sterilize th e operat ive eld w idely. Th e in cision s are m arked. In lt rat ion w ith 1% lidocain e w ith 1:100,000 epin eph rin e is opt ion al.
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II Spinal Em ergency Procedures
Operative Procedure Posterior Approach (Fig. 14.1a, b)
a
b
Fig. 14.1a, b Case example: posterior xation. This young man was involved in a motor vehicle accident and presented with a complete spinal cord injury at C6-C7. (a, b) CT im ages demonstrate the bilateral facet subluxation injury along with some additional posterior elem ent injuries and distraction indicating circumferential ligamentous disruption. Because of the degree of distraction and posterior element injuries, a long segment posterior xation was planned.
216
14
Cervical Facet Dislocation
Positioning (Fig. 14.2)
Figure
Procedural Steps
Pearls
Fig. 14.2
Cervical immobilization is maintained at all times. The neck is maintained in neutral alignment. Tongs w ith traction are maintained to stabilize the spine.
• Fiberoptic intubation is a necessit y in these patients. May eld pins may also be used to stabilize the spine.
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II Spinal Em ergency Procedures
Subcutaneous Dissection (1) (Fig. 14.3)
218
Figure
Procedural Steps
Pearls
Fig. 14.3
After a midline skin incision is made, dissection is carried dow n through the subcutaneous adipose tissue and cervical fascia until the spinous processes are exposed.
• Maintaining m idline is crucial not only for localization but also for m aintenance of hem ostasis.
14
Cervical Facet Dislocation
Subcutaneous Dissection (2) (Fig. 14.4)
Figure
Procedural Steps
Pearls
Fig. 14.4
Dissection of the paraspinous musculature is carried out laterally, exposing the facet joints. The muscle is mobilized in the subperiosteal plane.
• Care m ust be taken to leave norm al facet joints intact, especially directly above and below the injured level(s). The length of the skin incision determ ines the extent of lateral exposure. Lengthen the incision if needed.
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II Spinal Em ergency Procedures
Decompression and Reduction (Fig. 14.5)
220
Figure
Procedural Steps
Pearls
Fig. 14.5
Once the injured level has been identi ed (visually and via intraoperative X-ray), removal of compressive bony elements and reduction of the dislocated segment can begin using a series of rongeurs, punches, and curettes. Reduction may require drilling of the superior facet. Care is taken to save all bony elements for the fusion.
• Bone rem oval should be lim ited to that which is required for decompression. Reduction of the deform it y itself usually provides the decompression.
14
Cervical Facet Dislocation
Preparation for Fusion (Fig. 14.6)
Figure
Procedural Steps
Fig. 14.6
Follow ing decompression, decortication of the lateral elements and usually the facet joint itself should be carried out to provide an adequate fusion substrate.
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II Spinal Em ergency Procedures
Screw Placement (1) (Fig. 14.7a–c)
c
a
222
b
Figure
Procedural Steps
Pearls
Fig. 14.7
The entry point is 1 mm medial and inferior to the midpoint of the lateral mass. The screw trajectory may be estimated by aligning the drill guide w ith the rostral edge of the subadjacent spinous process. The angle should be “up (b) and out (c),” aiming aw ay from the vertebral artery (running underneath the medial half of the lateral mass) and the exiting nerve root and subadjacent facet (generally vulnerable if the screw trajectory is too caudal).
• Screw length is individual and should be determ ined preoperatively on CT. Either unicortical or bicortical purchase is associated with excellent outcom es and clinically adequate purchase in both the anterior and posterior approaches.17,18 If the construct crosses the cervicothoracic junction, polyaxial screws a ord the greatest exibilit y in rod placem ent. In the subaxial cervical spine, either rod-based or plate-based system s m ay be used with high success rates.
14
Cervical Facet Dislocation
Rod Placement (Fig. 14.8)
Figure
Procedural Steps
Fig. 14.8
A rod is fashioned to recreate the natural cervical lordosis and is placed in the screw heads. The caps are tightened in place.
223
II Spinal Em ergency Procedures
Posterolateral Fusion (Fig. 14.9)
224
Figure
Procedural Steps
Fig. 14.9
The bone fragments removed during the decompression, having been cleaned of all soft tissue and morselized, are placed in the decorticated facet joints and over the available lateral mass to complete the fusion.
14
Closing
• Th e deep subcut an eous t issue is closed using 2-0 absorbable
Posterior • Follow ing ach ievem en t of h em ost asis, drain p lacem en t is •
opt ion al. If placed, th e drain sh ould be placed in a su bfascial fash ion to allow closu re of th e cer vical fascia. Th e deep cer vical fascia is closed using n o. 0 absorbable braided sut u res in eith er an in terrupted or run n ing fash ion .
Cervical Facet Dislocation
• •
braided su t ures in an in terrupted fash ion . Th e purpose is to decrease th e dead space available for in fect ion . Th is is n ot a st rength layer. Th e deep derm is is closed u sing 2-0 or 3-0 absorbable braided su t u res in an in terru pted , inverted fash ion . Th e skin m ay be closed w ith staples, a ru n n ing n on absorb able su t u re, or an absorbable su bcu t icu lar su t u re.
Anterior Approach (Fig. 14.10a–c)
a
b
c
Fig. 14.10a–c Case example: reduction and anterior xation. This middle-aged woman presented following a fall with a severe C6 (ASIA B) spinal cord injury. (a) Sagit tal and (b) parasagit tal CT images demonstrate the facet subluxation injury and fracture. (c) She was brought directly to the operating room where traction was applied, almost completely reducing the subluxation.
225
II Spinal Em ergency Procedures
Positioning (Fig. 14.11)
226
Figure
Procedural Steps
Pearls
Fig. 14.11
The patient is positioned supine w ith the neck in a neutral position.
• Gardner Wells tongs m ay be placed if desired for intraoperative axial traction. Removal of im mobilization devices should be perform ed by a trained m em ber of the surgical team who is responsible for m aintaining a neutral alignment.
14
Cervical Facet Dislocation
Opening (Fig. 14.12)
Figure
Procedural Steps
Pearls
Fig. 14.12
An incision along the contour of the skin of the neck is made. The dissection is carried dow n to the platysma w ith monopolar electrocautery. The platysma is then divided sharply along its bers using Metzenbaum scissors.
• The incision t ypically is t wo-thirds anterior to and one-third posterior to the anterior border of the sternocleidomastoid muscle.
227
II Spinal Em ergency Procedures
Exposure of the Spinal Column (Fig. 14.13)
228
Figure
Procedural Steps
Pearls
Fig. 14.13
With the carotid sheath and its contents retracted laterally and the trachea and esophagus medially, the prevertebral fascia and longus colli muscles can be seen overlying the bony elements of the cervical spine.
• The space bet ween the carotid sheath is a potential space that can be created using blunt nger dissection.
14
Cervical Facet Dislocation
Exposure of the Vertebral Bodies and Intervertebral Disks (Fig. 14.14)
Figure
Procedural Steps
Pearls
Fig. 14.14
The appropriate level is identi ed by intraoperative X-ray. The longus colli are elevated and retracted laterally so that the uncovertebral joints are exposed bilaterally. Self-retaining retractors are inserted to a ord continuous exposure of the spinal column.
• The transverse processes lie along the superior border of each vertebral colum n so that injury to the vertebral artery is prevented here. The opposite is true at the inferior aspects of the vertebral bodies and care should be taken to avoid indiscrim inate use of m onopolar electrocautery.
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II Spinal Em ergency Procedures
Diskectomy (Fig. 14.15)
230
Figure
Procedural Steps
Fig. 14.15
The intervertebral disk and the posterior longitudinal ligament are removed using Kerrison punches and pituitary instruments, resulting in exposure of the spinal cord dura.
14
Cervical Facet Dislocation
Reduction (if necessary) (Fig. 14.16)
Figure
Procedural Steps
Fig. 14.16
Caspar pins are placed into the vertebral bodies and distraction and hyper exion is applied using either the Caspar pin appliers or pliers. Usually, the facet reduction is palpable and the vertebral bodies are then allow ed to return to an anatomic position. Fluoroscopy or a lateral radiograph is used to check alignment prior to graft placement.
231
II Spinal Em ergency Procedures
Graft Placement and Fusion (Fig. 14.17a, b)
a
232
b
Figure
Procedural Steps
Pearls
Fig. 14.17
(a) The vertebral endplates are decorticated. (b) A tricortical graft is then tted in the intervertebral space. The graft should be recessed below the anterior cortical margin to avoid migration of the graft.
• Care m ust be taken to avoid overdistraction due to an oversized graft.
14
Cervical Facet Dislocation
Plating (Fig. 14.18)
Figure
Procedural Steps
Pearls
Fig. 14.18
An appropriate size plate is placed in the midline of the vertebral column and a xed using unicortical screw s.
• The screws are directed m edially and either superiorly or inferiorly into the superior and inferior vertebral body, respectively.
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II Spinal Em ergency Procedures
Closing
Radiographic
Anterior
• A postoperat ive CT scan m ay be obtain ed to evaluate th e
• Ret ract ion is rem oved slow ly w ith all poin t s of bleeding
•
• • • •
coagu lated u sing bipolar elect rocauter y. Th e plat ysm a is closed using 2-0 absorbable braided sut ures. Th e pu rpose is reapproxim at ion an d does n ot h ave to be w ater-t igh t . Dead-space closu re of th e su bcu t an eou s t issu e w ith 2-0 ab sorbable braided su t u res is opt ion al. Closure of th e deep derm is is com pleted using 3-0 absorbable braided sut ures. Th e skin m ay be closed using a subcut icu lar st itch , t ypically 4-0 braided or m on o lam en t absorbable sut ure, a layer of brin glue, or a com bin at ion of th e t w o.
Postoperative Management Monitoring • Pat ien t s w ith severe n eu rologic inju ries are adm it ted to th e
•
ICU for aggressive blood pressu re m on itoring w ith th e in ten t to m ain tain at least a “n orm al” m ean arterial p ressu re. Pat ien t s w ith severe injuries frequen tly require uid an d pressor su p port to m ain tain m ean arterial p ressu res of at least 85 to 90 m m Hg.19 Pu lm on ar y care as w ell as recogn it ion of associated m edical issu es is facilitated by ICU placem en t . Pat ien t s w ith n o n eu rologic de cit s w ith u n com p licated p rocedures m ay be adm it ted to a gen eral care oor w h ere m on itoring is rou t in e an d m ost com m on ly related to th e t reat m en t of injur y-related an d postoperat ive discom fort .
Medication Pain Management • Acetam in oph en 1000 m g by m ou th (PO) th ree t im es a day • Oxycodon e 5 to 15m g (u p to 20 m g) PO ever y 3 to 4 h ou rs as • • • •
n eeded Gabapen t in 300 m g (up to 900 m g) PO th ree t im es a day Diazepam 5 to 10 m g PO ever y 6 h ou rs as n eeded for m u scle spasm s (opt ion al) Longer act ing oxycod on e 10 m g PO t w ice a day (in crease as n eeded) Narcot ics an d gabap en t in are w ean ed as rapidly as p ossible.
Other • All n on steroidal an t i-in am m ator y drugs are avoided for at •
234
least 3 m on th s. Proch lorperazin e an d droperidol are avoided if possible due to th eir sedat ing e ects w h ile th e p at ien ts are requ iring sign i can t doses of pain m edicat ion s.
placem en t of th e screw s an d th e exten t of reduct ion . Pat ien ts are follow ed on an ou t pat ien t basis w ith an teroposterior an d lateral plain lm s of th e cer vical spin e at 1 m on th , 3 m on th s, an d 6 m on th s for evaluat ion of th e exten t of fusion . Fig. 14.19 sh ow s n al con st ruct of posterior approach an d Fig. 14.20 sh ow s n al con st ru ct of an terior ap p roach .
Further Management • It is ou r pract ice to rem ove drain s w h en th e ou t pu t drops be•
low 100 m L in a sh ift . Skin su t u res/st ap les th at are n ot absorbable are rem oved 2 w eeks postoperat ively.
Special Considerations It is im portant to consider th e exten t of the injur y in ch oosing an operat ion. W hile closed reduct ion follow ed by extern al im m obilizat ion is overall a safe m odalit y that can be perform ed at the bedside,4,20,21 it is gen erally m ost su ccessfu l in inju ries lim ited to the osseous com ponen ts of th e spine.20,21 In gen eral, facet dislocation involves the ligam entous st ruct ures of the spine in addition to the osseous elem en ts. Therefore, internal xation is usually felt to be m ore appropriate. Th e ch oice of approach is m ore debatable. Posterior fusion has been thoroughly st udied an d foun d to be appropriate for cer vical facet dislocat ions.22,23 Both an terior an d posterior approach es h ave been su ccessful, but th e gu idelin es adopted by th e Am erican Associat ion of Neurological Surger y and the Congress of Neurological Surgeon s favor the posterior approach w ith som e t ype of lateral m ass xation.12 Th e quest ion of im aging for evaluat ion of vertebral arter y in jur y is on e of sign i can t con t roversy. A 2006 m et a-an alysis 24 fou n d th e in ciden ce of vertebral arter y inju r y (VAI) in facet dislocat ion w ith or w ith out associated fract ure to be 21 to 75% (m ean , 35%). VAI w as m ore likely to occur in un ilateral rath er th an bilateral facet dislocat ion s. Due to sign i can t collateral ow, on ly 12 to 20% of th e VAIs iden t i ed w ere sym ptom at ic. Th e 2002 guidelin es,25 in a st atem en t regarding VAI, recom m en d ed again st an t icoagu lat ion for asym ptom at ic p at ien ts as th e in h eren t risk of an ticoagulat ion itself w as rough ly equivalen t to th e risk of st roke in h eren t to a VAI. Th e 2013 guidelin es 26 su p p or ts CT angiography in select p at ien ts m eet ing clin ical (sym ptom s an d sign s) an d radiograph ic criteria. In addit ion , t reat m en t decision for VAI (an t icoagulat ion , an t iplatelet th erapy, obser vat ion ) sh ou ld be based u pon clin ical circu m st an ces. Th e qu est ion th en is w h eth er to im age th e pat ien t in order to detect th ese injuries. In follow ing th e gu idelin es, if th e pat ien t is asym ptom at ic, vascular st udies to iden t ify asym ptom at ic in juries are n ot n ecessar y as th ey w ou ld n ot ch ange m an agem en t . If th ere are im aging st u dies p lan n ed for oth er reason s, con siderat ion can be given to im aging of th e ver tebral arteries.
14
Cervical Facet Dislocation
a
Fig. 14.20 Postoperative image of patient in Fig. 14.10. An anterior cervical diskectomy and fusion were performed with completion of the reduction achieved through direct manipulation of the vertebral bodies using vertebral pins. Plate xation provided immediate stabilization and she was discharged to rehabilitation in a collar for 6 weeks.
References
a Fig. 14.19a, b Postoperative images of patient depicted in Fig. 14.1. (a) Once stabilized, he was brought to the operating room for an open posterior reduction and (b) stabilization using lateral mass screws in the mid cervical spine and pedicle screws in C7 and T1.
1. Da n er RH. Evalu at ion of cer vical ver tebral inju ries. Sem in Roen tgen ol 1992;27:239–253 2. Ben zel EC. Trau m a, t u m or, an d in fect ion . In : Biom ech an ics of Spin e St abilizat ion . New York: Th iem e; 2001:79 3. Wickst rom JK, Mar t in ez JL, Rodrigu ez R Jr. Hyperexten sion an d hyper exion injuries to th e h ead an d n eck of prim ates. In : Gu rdjian ES, Th om as LM, eds. Neckach e an d Backach e: Proceedings Worksh op of th e Am erican Associat ion of Neurological Su rger y an d th e Nat ion al In st it u te of Health . Spring eld, IL: Th om as; 1970 4. Gelb DE, Hadley MN, Aarabi B, et al. In it ial closed redu ct ion of cer vical spin e fract ure-dislocat ion injuries. Neurosurger y 2013;72(suppl):73–83
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II Spinal Em ergency Procedures 5. Cotler JM, Herbison GJ, Nasu t i JF, Dit u n n o JF Jr, An H, Wol BE. Closed reduct ion of t raum at ic cer vical spin e dislocat ion using t ract ion w eigh t s up to 140 poun ds. Spin e 1993;18(3): 386–390 6. Hadley MN, Beverly CW, Grabb PA, et al. Ph arm acological th erapy after acute cer vical spin al cord injur y. In : Neu rosurger y Sect ion on Disorders of th e Spin e an d Periph eral Ner ves of the Am erican Associat ion of Neu rological Surgeon s an d th e Con gress of Neurological Surgeon s Gu idelin es for th e m an agem en t of acute cer vical spin e an d spin al cord injuries. Neu rosurger y 2002;50(S3):S63–72 7. Hu rlber t RJ, Hadley MN, Walters BC, et al. Ph arm acological th erapy for acute spinal cord injur y in Guidelin es for th e m an agem en t of acu te cer vical sp in e an d spin al cord inju ries. Neu rosu rger y 2013;72 [suppl 2]:93–105 8. Bracken MB, Sh epard MJ, Hellen bran d KG, et al. Methylpredn isolon e an d n eurological fun ct ion 1 year after spin al cord injur y. Resu lt s of th e Nat ion al Acu te Spin al Cord Injur y St udy. J Neu rosurg 1985;63:704–713 9. Bracken MB, Sh ep ard MJ, Collin s W F, et al. A ran d om ized, con t rolled t rial of m ethylpredn isolon e or n aloxon e in th e t reat m en t of acute spin al-cord injur y. Result s of th e Secon d Nat ional Acute Spin al Cord Inju r y St udy. N Engl J Med 1990;322:1405–1411 10. Bracken MB, Sh ep ard MJ, Collin s W F Jr, et al. Methylp redn isolon e or n aloxon e t reat m en t after acu te spin al cord inju r y: 1-year follow -up dat a. Result s of th e secon d Nat ion al Acute Spin al Cord Injur y St udy. J Neurosu rg 1992;76(1):23–31 11. Gelb DE, Aarabi B, Dh all SS, et al. Treat m en t of su baxial cer vical spin e injuries. Neurosurger y 2013;72[suppl 2]:187–194 12. Rein dl R, Ou ellet J, Har vey EJ, et al. An terior redu ct ion for cer vical spin e dislocat ion . Spin e 2006;31:648–652 13. Joh n son MG, Fish er CG, Boyd M, et al. Th e rad iograp h ic failu re of single segm en t an terior cer vical plate xat ion in t raum at ic cervical exion dist ract ion inju ries. Spin e 2004;29:2815–2820 14. Maim an DJ, Barolat G, Larson SJ. Man agem en t of bilateral locked facet s of th e cer vical spin e. Neu rosu rger y 1986;18:542–547
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15. De Iu re F, Scim eca GB, Palm isan i M, et al. Fract u res an d dislocat ion s of th e low er cer vical spin e: surgical t reat m ent . A review of 83 cases. Ch ir Organ i Mov 2003;88:397–410 16. Ordon ez BJ, Ben zel EC, Naderi S, et al. Cer vical facet d islocat ion : tech n iques for ven t ral reduct ion an d st abilizat ion . J Neurosurg 2006;92:18–23 17. Leh m an n W, Blauth M, Briem D, Sch m idt U. Biom ech an ical analysis of anterior cer vical spin e plate xat ion system s w ith un icort ical and bicor t ical screw purchase. Eur Spine J 2004;13(1):69–75 18. Seybold EA, Baker JA, Criscit iello AA, Ordw ay NR, Park CK, Con n olly PJ. Ch aracterist ics of un icor t ical an d bicor t ical lateral m ass screw s in th e cer vical spin e. Spin e 1999;24(22):2397–2403 19. Ryken TC, Hu rlber t RJ, Had ley MN, et al. Th e acu te cardiop u lm on ar y m an agem en t of pat ien t s w ith cer vical spin al cord injuries. Neurosu rger y 2013;72[suppl 2]:84–92 20. Bucholz RD, Chang KC. Halo vest versus spinal fusion for cervical injury: Evidence from an outcom e study. J Neurosurg 1989;71(6):955 21. Son t ag VK, Hadley MN. Non operat ive m an agem en t of cer vical spin e injuries. Clin Neurosurg 1988;34:630–649 22. Hadley MN, Fit zp at rick BC, Son n t ag VK. Facet fract u re- dislocat ion injuries of the cer vical sp in e. Neu rosurger y 1992;30:661–666 23. Mon roe MA, Ball PA. Spin al t ract ion . In : Ben zel EC, ed. Sp in e Surger y: Tech n ique, Com plicat ion , Avoidan ce, an d Man agem en t . Ph iladelph ia: Saun ders; 1999:1353–1362 24. In am asa J. Gu iot BH. Ver tebral ar ter y inju r y after blu n t cer vical t raum a: an update. Surg Neurol 2006;65:238–246 25. Hadley MN, Beverly CW, Grabb PA, et al. Man agem en t of vertebral arter y injuries after n onpen et rat ing cer vical t raum a. In : Neurosu rger y Sect ion on Disorders of th e Spin e an d Periph eral Ner ves of th e Am erican Associat ion of Neurological Surgeons an d th e Congress of Neu rological Su rgeon s Gu idelin es for th e m an agem en t of acute cer vical spin e an d spin al cord injuries. Neurosu rger y 2002;50(3):S173–S178 26. Harrigan MR, Hadley MN, Dh all SS, et al. Man agem en t of ver tebral arter y injuries follow ing n on -pen et rat ing cer vical t raum a. Neurosu rger y 2013;72[suppl 2]:234–243
15
Classi cation and Treatment of Thoracic Fractures Joseph Hsieh, Doniel Drazin, Michael Turner, Ali Shirzadi, Kee Kim , and J. Pat rick Johnson
Introduction Th oracic fract ures in h ealthy in dividuals are un com m on due to th e st abilizing e ect of th e rib cage. How ever, h igh en ergy t raum a an d predisposing con dit ion s can in crease th e likelih ood of fract u re.1 Alth ough th ere is n o id eal st an dard for classi cat ion of th oracolu m bar (TL) inju ries, th e evolu t ion of th e th ree- colu m n m odel of Den n is, th e AO/Magerl com p reh en sive classi cat ion , an d th oracolu m bar injur y severit y scale an d score (TLISS)/th oracolu m bar inju r y classi cat ion an d severit y score (TLICS) poin t system h ave provided sign i can t in sigh t in to an atom y, m ech an ism of injur y, an d th e im plicat ion s an d th erapies for in st abilit y.2–4 Mu lt iple su rgical tech n iqu es add ress spin al in st abilit y, bu t th e ch oice of su rger y d ep en ds on th e level of injur y an d an atom y.
Facets • Th e art icular processes arise from th e su perior an d in ferior • •
Ribs • Th e m ost dist inguish ing feat ures of th e th oracic spin e are th e
Indications Th e goal of th oracic spin e fract ure t reat m en t is preven t ing deform it y, p roviding st abilit y, an d p rotect ing th e n eu ral elem en t s. If con ser vat ive m an agem en t is deem ed in su cien t to p rovide th ese goals, th en surgical m an agem en t sh ould be con sidered. Su rger y sh ou ld be also con sidered as an adju n ct to h asten reh abilitat ion , sh or ten h ospit al st ays, an d par t icu larly in cases of m u lt iple inju r y.
Anatomy Th e th oracic spin e is th e longest spin e segm en t an d a com m on site for t rau m a, esp ecially at it s low er segm en t s (T10-T12).5 Th e th oracic spin e con sist s of 12 vertebrae w ith a physiologic kyph ot ic cur ve due to w edging of th e th oracic ver tebrae (a 2- to 3-m m di eren ce in an terior an d posterior h eigh t).6
• •
•
• Th e th oracic can al is n arrow ed w ith less free space for th e
Bony Structure
•
arch es posteriorly resist ten sion . Th e an terop osterior (AP) diam eter of th e VB in creases from T1 to T12, w h ile th e t ran sverse d iam eter decreases from T1 to T3 an d th en in creases to T12.7 Th e VB sides are con cave an d th e lam in ae are broad an d h eavily overlapp ed. Th e pedicles p roject from th e sup erior VB posteriorly. Th e lam in ae exten d dorsom edially from th e pedicles to fu se an d form th e dorsal w all of th e spin al can al.
ribs an d th eir t w o vertebral art icu lat ion s. Sp eci cally, th e rib h ead s art icu late w ith th e vertebrae an d th e disk. Th e rib t ubercle ar t iculates w ith th e t ran sverse process at th e costot ran sverse ar t icu lat ion . Dem ifacets above and below the disk articulate w ith the head of the rib to form the costovertebral joint (a synovial joint divided by an intraarticular ligam ent into t wo separate com partm ents). Overall, th e rib cage provides th e th oracic spin e w ith t w o to three t im es the load bearing capacit y before in stabilit y relat ive to oth er spin e segm en ts. Sagit tal an d lateral exion - exten sion are also stabilized. Th erefore, h igh m ech an ical forces m u st occur to cause thoracic vertebral injuries—often w ith con current injuries to the ch est, cer vical spin e, and head.9 Th e radiate an d costot ran sverse ligam en t s bin d th e ribs to th eir ver tebrae addit ion ally an d provide st abilizat ion .10
Spinal Cord •
• Th e ver tebral bodies (VB) an teriorly are load bearing an d th e
lam in ar surfaces. From T1 to T10, the thoracic facets are oriented coronally. This m inim izes an terior translation during exion. From T11 to T12, the facets have an oblique sagittal orientation to lim it rotation. Th e coron al facet orien t at ion of th e upper th oracic spin e allow s for rotat ion aroun d th e cran iocaudal axis (75 degrees of rot at ion to each side) w ith th e greatest rot at ion at T8-T9.8 In con t rast , lu m bar spin e rot at ion is lim ited by th e orien tat ion of th e facet s an d an terior an n ulus to on ly 10 degrees.
•
spin al cord com pared to th e cer vical spin e. Th e cen t ral th oracic spin e also h as a lim ited blood su pply, w ith a low er th resh old for vascular cord injur y on kyph osis or com pression th an th e lum bar spin e. Sp in al cord inju r y to th e u p per th oracic spin e can h ave d evast at ing sequ elae w h ile root inju r y in th e th oracic sp in e is far less fun ct ion ally relevan t th an in th e lu m bar sp in e.
Evaluation and Diagnosis In it ial evalu at ion of t rau m a involves assessm en t for seriou s life-th reaten ing injuries w ith rapid resu scitat ion as n ecessar y.
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II Spinal Em ergency Procedures Sp in al inju r y, w h ile com m on in m u lt ip le-system t rau m a, is frequen tly un recogn ized.11
Indications for Surgical Management
Physical Spine Examination
• Su rgical d ecom p ression is in dicated w h en th ere is n eu ral
• A th orough sp in e exam in at ion is crit ical in th e in it ial com p re• • •
h en sive t rau m a evalu at ion . Direct exam in at ion in clu des visu al in sp ect ion an d palp at ion of all spin al segm en t s. A step -o , localized ten dern ess, or a soft sp ot (from lacerat ion , sw elling, or ecchym osis) m ay be th e on ly sign of in st abilit y. Soft-t issu e t rau m a to th e ch est or abdom en m ay suggest a seat-belt inju r y w ith a TL exion -dist ract ion inju r y.
•
Neurologic Examination • Neu rologic exam sh ou ld in clu de m otor st rength , sen sor y • • • • • •
fu n ct ion , an d re exes. If sp in al cord inju r y is su sp ected, serial exam s are n ecessar y as th e n eu rologic exam m ay ch ange, esp ecially in set t ings of in st abilit y. Grading by th e Am erican Spin al Inju r y Associat ion (ASIA) Im pairm en t Scale docum en t s th e level an d severit y of th e spin al cord injur y. A rep eat evalu at ion sh ou ld be perform ed if in it ial evalu at ion is in adequ ate. Pat ien t s w ith sp in al cord inju r y sh ou ld be tested for perian al sen sat ion , rect al ton e, an d bu lbocavern osu s re ex. Any su sp icious n dings w arran t im aging. Sp in e precau t ion s sh ou ld rem ain in place u n t il sp in al t rau m a is exclu ded. Sp in al fract u res are m issed frequ en tly in set t ings of m u lt ip le inju ries.12–15
Indications for Conservative Management • Con ser vat ive m an agem en t sh ould be con sidered anyt im e a p at ien t can m ain t ain align m en t an d n eu rologic st abilit y w ith ou t su rger y.1 St able fract u res su ch as un com plicated com pression fract ures m ay n ot require bracing as th e rib cage an d stern u m bu t t ress th e sp in e.
Orthoses • If su pport is n eeded, com pression fract ures are rout in ely
•
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t reated w ith an orth osis often w ith in clusion of th e cer vical sp in e. Cer vical su p port cou ld in clu de a m an dible, occipital pads, or halo ring an d m ay consist of a cer vicoth oracic orth osis (CTO) or cer vicothoracolum bosacral orth osis (CTLSO). Orth oses an d casts sh ou ld be u sed w ith cau t ion ◦ Sen sor y de cits m ay lead to w ou n d breakdow n du e to pressure ulcerat ion s from an orth osis. Skin con t act sh ould be ch ecked frequen tly an d rout in ely. Em aciated pat ien t s w ith poor soft t issue padding are especially at risk. ◦ Orth oses an d cast s m aybe di cu lt for p at ien t s to rem ove an d th e t m ay n eed to be adju sted over t im e.
•
com pression w ith w orsen ing n eu rologic de cit , w h ich m ay in clu de w orsen ing m yelopathy or radicu lopathy.1 ◦ In cases w h ere th e inju r y is com plete, ASIA A, su rger y w ill likely n ot resu lt in n eu rologic im provem en t; h ow ever, st abilizat ion of th e spin e m ay be ben e cial in facilit at ing reh abilitat ion an d pat ien t t ran sfers. Su rgical stabilizat ion is in dicated for w orsen ing n eu rologic de cit , disrupted posterior ligam en tous com plex (PLC), dislocat ion of th e th oracic spin e, failure to obtain or m ain t ain correct ion by n on surgical m ean s, un acceptable deform it y, an d in toleran ce to n on su rgical m an agem en t . ◦ Den is described a th ree-colu m n m odel of th e spin e.2 Many believe th at m ech an ical in st abilit y results from disrupt ion of t w o or th ree of th e th ree colum n s. ◦ Th e TLICS/TLISS p rovides gu id elin es for w h en su rgical in ter ven t ion is w arran ted. 4 W h ile a com pression fract ure of th e an terior colum n m ay be m ech an ically stable in th e sh ort term , sign i can t kyp h osis or VB collapse m ay lead to progressive deform it y over t im e. ◦ Coh en et al recom m en d operat ive redu ct ion an d fu sion for any n eu rologic dysfu n ct ion th at m eets th e follow ing criteria 16 : ▪ If any of th e com pressed vertebrae w edge fract ures m easu re over 40% in a you ng or m iddle aged adu lt ▪ If th e com pression p ercen tages for th e adjacen t ver tebral w edge fract u res com bin e to greater th an 50% ▪ Acute kyph osis is presen t ◦ Mu n t ing recom m en ds su rger y w h en sign i can t pain com bin ed w ith altered fun ct ion is reported for a post t raum at ic deform it y exceeding 20 degrees of sagit t al in dex.17 ▪ Pain is often located abou t th e apex of th e deform it y. Th is kyph ot ic deform it y m ay lead to com pen sator y hyperlordosis in th e lu m bar spin e an d/or hypokyph osis or even lordosis in th e th oracic sp in e above th e lesion an d cause pain ful m uscle spasm . ▪ Oth er in dicators for surger y in clude in abilit y to m ain t ain st raigh t vision du e to severe kyp h osis, pseu doar th rosis, disk degen erat ion , progressive n eurologic de cit , an d cosm esis.
Preprocedure Consideration Radiographic Imaging Correct diagnosis w ith physical exam m ay be di cult, particularly in patients w ith altered m ental status, patients w ho are intubated or sedated, and patients w ith m ultiple pelvis or lim b fractures. Initial im aging (plain radiography or CT) is crucial in these cases.
Plain Radiography • AP an d lateral plain X-rays of th e th oracic an d lu m bar spin e allow th e p hysician to cou n t th e n u m ber of rib - bearing vertebrae an d th e n um ber of lum bar vertebrae to en sure accu racy
15 Classi cation and Treatm ent of Thoracic Fractures of surgical plan n ing. Care sh ou ld be taken to evaluate for p ossible an atom ic varian t s (e.g., cer vical ribs or lu m barized sacral ver tebrae). How ever, th e u p per th oracic colu m n is p oorly visu alized on plain radiography.
•
Computed Tomography • Modern com puted tom ography (CT) allow s rapid characteriza-
• • •
tion of spinal fracture m orphology and provides critical detail in the acute and therapeutic setting.1 In a study by Sm ith et al, nonreconstructed CT detected TL fractures m ore accurately than plain radiographs and is recom m ended for diagnosis of TL fractures in acute traum a for patients w ith altered m ental status.18 In form at ion in clu des can al n arrow ing d u e to ret rop u lsed fragm en t s, bet ter evalu at ion of u n st able rot at ion al inju ries, an d in d irect assessm en t of ligam en tou s an d d isk inju ries. Facet dislocat ion an d posterior in terspin ous w iden ing due to dist ract ion m ay dem on st rate a “n aked facet sign .” CT m yelogram m ay dem on st rate areas of com p ression of th e th ecal sac.
Magnetic Resonance Imaging • Magn et ic reson an ce im aging (MRI) dem on st rates associated • •
soft t issu e inju r y th at w ill n ot be visible on th e CT. Occasion ally decom pression of th e sp in al cord from th ese soft t issu e elem en ts w ill be in dicated even for fract u res th at app ear to be st able on CT. If th e fract u re ap pears to be associated w ith som e p ath ology, th en it m ay be h elpful to in clude en h an ced im ages in th e MRI to determ in e if th e bon e appears to h ave an associated in fect ion or t um or.
Medication
•
•
•
• Steroids h ave had w axing an d w an ing p opularit y in th e set-
•
t ing of acute spin al cord injur y. If th ere is a neurologic injur y, som e report s h ave in d icated th at h igh dose m ethylp redn isolon e h as given som e ben e t .19 How ever, th ese in it ial repor t s h as n ot been replicated, an d th e risk to th e p at ien t con com it an t w ith steroid use in clu ding life-th reaten ing in fect ion s is n ot in con siderable.20 Recen t gu idelin es h ave recom m en ded again st th eir u se.21 An t ibiot ics: If th e pat ien t h as an associated in fect ion , it m ay be ben e cial to obtain a specim en for cult ure prior to st ar t ing an t ibiot ics. Oth er w ise st an dard preoperat ive an t ibiot ics are u sed, t ypically cefazolin .
Operative Management
•
Guidelines for Management • Th ere is n o con sen sus on th e best t reat m en t for TL spin e inju ries. As a rule of th um b, posterior decom p ression (e.g., lam in ectom y) m ay be e ect ive for posterior spin al cord com pression in a st able spin e. How ever, lam in ectom y w ith out in st rum en t at ion m ay dest abilize a spin e th at already h as dam age to an oth er colu m n an d th erefore is in appropriate w h en ever stabilit y is in quest ion . For an terior com pression ,
t ypically an terior approach is preferred w ith con siderat ion of an atom ic lim it at ion s. McAfee et al p rovided on e of th e earliest gen eral t reat m en t gu id elin es based on sp eci c inju r y p at tern s.22 ◦ Com p ression fract u re: obser vat ion w ith follow -u p or p refabricated brace im m obilizat ion for 12 w eeks ◦ St able bu rst: cu stom t t ing orth osis or cast im m obilizat ion for 12 w eeks. L4 an d above: TLSO; L5: HTLSO; if kyp h osis . 15 degrees, hyperexten sion cast . ◦ Un stable bu rst: su rgical decom p ression an d st abilizat ion (approach con t roversial). Con sider em ergen t posterior sh or t-segm en t d ecom p ression an d fu sion (w ith extern al im m obilizat ion in a custom TLSO for 12 w eeks), an d delayed an terior decom pression an d fusion if th e p at ien t h as n eu rologic d e cit an d residu al cord/root com pression . ◦ Flexion -dist ract ion (an d Ch an ce inju r y): con sider hyperexten sion cast for a p u rely osseou s inju r y w ith n o associated n eurologic de cit . Con sider posterior sh or t-segm en t st abilizat ion an d fu sion for associated n eu rologic inju r y or abdom in al injur y or w h en spin e injur y is prim arily ligam en tou s. ◦ Fract u re-d islocat ion : p osterior long-segm en t su rgical st abilizat ion w ith pedicle screw xat ion t w o to th ree levels above an d below th e inju r y w ith local bon e graft fu sion . In t h e 1990s, t h e rst m u lt icen ter st u dy (MCSI) of t h e Sp in e St u dy Grou p of t h e Ger m an Associat ion of Trau m a Su rger y sh ow ed lim it at ion s for isolated p oster ior in st r u m en t an d fu sion tech n iqu es in cases w it h a com p rom ised an ter ior colu m n . Sin ce then , operat ive approach es an d adju n cts h ave advan ced con siderably to in clude en doscopic an d m in im ally invasive su rger y—advan ces in in terbody su p p or t an d in t raoperat ive n avigat ion . Th e secon d m ult icen ter st udy (MCSII) of th e Spin e St udy Group of th e Germ an Associat ion of Trau m a Su rger y review ed t rau m at ic TL (T1-L5) inju ries as an u p date to MCSI. Of 733 pat ien ts w ith acu te TL injuries t reated surgically 23 : ◦ 380 (51.8%) p at ien t s w ere op erated on by posterior st abilizat ion an d in st rum en tat ion alon e ◦ 34 (4.6%) h ad an an terior p rocedu re alon e ◦ 319 (43.5%) h ad com bin ed p osteroan terior p rocedu res. ◦ Overall th ey fou n d: ▪ Sh or t angular stable im plan t system s h ave replaced con ven t ion al n on angu lar stabilizat ion system s. ▪ Post t rau m at ic deform it y w as restored best w ith com bin ed posteroan terior surger y. ▪ Di eren t surgical approach es did n ot h ave a sign i can t in uen ce on n eurologic recover y on 2-year follow -up . ▪ Five percen t of all pat ien ts required revision surger y for p erioperat ive com p licat ion s. Th e m ost com m on surgical in ter ven t ion s for th oracic inju ries are described below.
Operative Field Preparation Positioning • Th e pat ien t is in t u bated supin e an d th en posit ion ed carefully •
as n eeded. Pressu re poin t s are padded.
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II Spinal Em ergency Procedures • In t raoperat ive m on itoring in clu ding som atosen sor y evoked poten t ials (SSEP) an d m otor evoked poten t ials sh ould be con sidered.
Localization • Im aging an d p hysical exam review is crit ical to d eterm in e th e su rgical levels. Preoperat ive im aging m ay in clu de localizat ion u sing cross t able lateral p lain lm s w ith a radiopaqu e m arker.
Prior to Incision • Th e skin is prepped in sterile fash ion an d th e in cision is in lt rated w ith lidocain e 1% w ith epin eph rin e 1:100,000
Approaches Su rgical ap proach es to th e th oracic sp in e can be divided in to posterior, posterolateral, an d an terior. These approach es can also be com bin ed in th e sam e p roced u re or staged . Ult im ately, th e approach w ill depen d on th e path ology, locat ion , spin al cord com pression , in st abilit y, an d m edical con dit ion .
Posterior Approach Poster ior ap p roach es to t h e t h oracic sp in e are t h e m ain st ay of sp in e p roced u res. Th e id eal p at h ology for t h ese ap p roach es is gen erally p oster ior to t h e sp in al cord . Th e m ost com m on p oster ior ap p roach (lam in ectom y w it h or w it h ou t in st r u m en t at ion ) is u sed com m on ly for rad icu lom yelop at hy from t h oracic d isk h er n iat ion , sp on dylosis, an d t rau m a w it h st able sp in e alon g w it h som e t u m ors an d in fect ion . How ever, it is d i cu lt to access ven t ral p at h ology w it h ou t r isk of sp in al cord inju r y. Th ese approach es can be tailored for access to a region of in terest from directly m idlin e to th e spin al can al (e.g., lam in ectom y) to fu rth er p osterolateral in at tem pt s to reach an terior to th e can al (e.g., t ran sp ed icu lar, costot ran sversectom y, lateral ext racavit ar y ap proach es).
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Posterolateral Approaches to the Anterior Thoracic Spine Posterolateral approaches to the anterior thoracic spine include the transpedicular, costotransversectomy, and posterolateral extracavitary. These provide progressively greater visualization of the anterior spine as exposure extends farther laterally from m idline w ith greater dissection of the ribs. The transpedicular corpectom y is the easiest progression from the direct m idline approach and is illustrated here. It avoids surgical m orbidit y of anterior exposure w hile providing relatively good access to the anterolateral spinal cord and m ay be perform ed in com bination to lam inectom y. The costotransversectomy utilizes a m idline or param edian incision and involves com plete rem oval of the rib head and transverse process and provides greater visualization for partial vertebrectom y. The lateral extracavitary approach utilizes a hockey stick posterolateral incision w ithout violating the chest cavit y and provides good visualization and decom pression of the anterior thecal sac. These approaches are discussed in Special Considerations
Anterior Approach: Thoracotomy Anterior exposure to the thoracic spine is often critical in traum a. Anterior exposure m akes it far easier to perform m ultilevel decom pression and stabilization through a single approach w ith possibilit y of anterior stabilization. For fractures involving the anterior elem ents of T1 or T2, an anterior approach can be used that is sim ilar to an anterior cervical corpectom y and fusion. However, T3-T5 cannot be reached e ectively from the front unless the chest is opened by perform ing a m anubrial resection or sternotom y and are often best accessed through a transthoracic approach. Tran sth oracic app roach es (e.g., th oracotom y an d th oracoscopy) provide several ben e ts in com parison to posterior or posterolateral approach es. A t ran sth oracic approach provides opt im al exposure of th e an terior dura an d posterior longit udin al ligam en t . How ever, th e t radeo in clu des redu ced exp osu re to th e posterior sp in e. Th ere are also associated com p licat ion s in clu ding pn eu m oth orax, pu lm on ar y con t u sion , pn eu m on ia, pleural e usion , em pyem a, an d possible n eed for an access su rgeon . W h ile th oracotom y is th e m ain stay, th oracoscopy h as becom e in creasingly an opt ion .
15 Classi cation and Treatm ent of Thoracic Fractures
Operative Procedure Posterior Approach (Fig. 15.1a–c and Fig. 15.2)
a
c
b
Fig. 15.1a–b Twent y-six-year-old man involved in an all-terrain vehicle accident. CT showed a T10-T11 fracture-dislocation with signi cant angulation of the thoracic spine. The spinous process of T10 is (a) fractured along with (b) dislocated and (c) jumped facets.
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Fig. 15.2 MRI in same patient showed narrowing of the spinal canal with cord compression at that level. Fortunately, the patient was moving his lower extremities.
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15 Classi cation and Treatm ent of Thoracic Fractures
Positioning and Localization (Fig. 15.3)
Figure
Procedural Steps
Pearls
Fig. 15.3
The patient is positioned prone on a radiolucent table w ith chest bolsters. Pressure points are padded. The level of surgery is determined and a posterior midline incision is planned. The surgical eld is prepped and draped.
• Positioning can lead to deterioration of the patient. In patients
•
with severe stenosis or instabilit y, it is helpful to obtain baseline SSEP prior to positioning. Surface electrodes are placed on the patient in the preoperative area to save tim e during patient positioning. Needle electrodes are placed after anesthesia is induced. Baseline is run in the room after anesthesia is induced for comparison after the patient is positioned and throughout the case. The level is determ ined anatom ically and m arked by taping a paperclip to the chest wall at the surgical level. A cross table lateral plain X-ray is taken and the surgical site m arked. It is optim al to count from the top and bot tom if possible. Prep a large area rostrally and caudally to allow for extension of the incision and to allow drain placem ent.
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Skin, Subcutaneous, and Subperiosteal Dissection (Fig. 15.4)
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Figure
Procedural Steps
Pearls
Fig. 15.4
The skin is in ltrated w ith lidocaine and the incision is opened w ith a no. 10 blade to the subcutaneous tissue. Hemostasis is obtained w ith monopolar cautery. The subcutaneous tissue is dissected dow n to the fascia w ith monopolar cautery. Cerebellar retractors are used at this point to re ect the tissue. The bone of the spinous process is palpated and a subperiosteal dissection is made by cutting the muscular and tendinous attachments directly o the bone. Dissection should continue dow n, follow ing the lamina, and out laterally to the beginning of the facet complex. If there is signi cant bleeding then it may be more e ective to sw itch to bipolar cautery to achieve hemostasis. The levels are veri ed by placing tw o metal instruments in the incision such that the tips mark the rostral and caudal extent of the anticipated bony dissection. A cross-table plain X-ray or uoroscopic image is taken to verify the correct level of surgery.
• A cell salvage m achine, if •
available, should be utilized. Care m ust be taken to prevent the monopolar cautery from slipping though the interlam inar space.
15 Classi cation and Treatm ent of Thoracic Fractures
Spinous Process Removal (Fig. 15.5)
Figure
Procedural Steps
Fig. 15.5
The interspinous ligament can be cut using monopolar cautery or scissors allow ing removal of the spinous process w ith a Horsley.
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Laminectomy, if Indicated (Fig. 15.6)
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Figure
Procedural Steps
Pearls
Fig. 15.6
Using a high speed drill, the lamina is thinned to a layer of cortical bone over the ligamentum avum. The bone can then easily be removed w ith a 2-mm Kerrison punch. Hemostasis should be achieved by application of bone w ax to the bleeding cut surface of the bone.
• Take care to avoid downward pressure with the Kerrison.
15 Classi cation and Treatm ent of Thoracic Fractures
Removal of Ligament (Fig. 15.7)
Figure
Procedural Steps
Pearls
Fig. 15.7
Once the laminectomy has extended anteriorly beyond the attachment of the ligamentum avum, it is easy to elevate aw ay from the thecal sac and remove w ith a Kerrison punch. Removal of the ligament w ill likely result in bleeding of epidural veins. If these are visible, these can be cauterized w ith bipolar cautery. Remove any remaining bone and ligament in the lateral recess (1). Probe the foramen w ith a ball probe or Woodson to make sure that the nerve roots are not severely compressed (2).
• Decrease the strength of the bipolar cautery •
prior to using the instrum ent near the thecal sac. For hem ostasis, apply bone wax to bleeding bone, and then apply a line of gelatin-throm bin matrix down the length of each gut ter. Cover with a pat tie and wait a few m inutes to allow clot form ation. Wash out the excess and repeat as needed.
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Thoracic Pedicle Screw Entry Point (Fig. 15.8)
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Figure
Procedural Steps
Pearls
Fig. 15.8
Start the entry point w ith an aw l or high speed drill. Use uoroscopy to verify position. Insert the pedicle nder through the cancellous bone of the pedicle (1). Use uoroscopy to verify position. Using a ne ball tipped probe, feel all four sides and the bottom of the hole to make sure that there is no breach (2).
• Screw entry point di ers at each level but is generally toward the m edial anterior quadrant of the facet complex. The pedicle nder generally has a slight curve to it and should be facing out ward initially, and then turned inward when the vertebral body is reached.
15 Classi cation and Treatm ent of Thoracic Fractures
Screw Placement (Fig. 15.9)
Figure
Procedural Steps
Fig. 15.9
Tap the hole w ith the appropriate sized tap (1). Insert the screw into the hole (2). Use uoroscopy to verify position.
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Rod Placement (Fig. 15.10)
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Figure
Procedural Steps
Fig. 15.10
When all pedicle screw s have been placed, insert a malleable temporary rod through the polyaxial screw heads to determine the shape and length of the rod. Cut the rod to the appropriate size, and bend it to t. Fit the rod though the screw heads and a x screw caps. When the rod ts and all screw caps are in place, use the nal tightener to lock the screw caps dow n.
15 Classi cation and Treatm ent of Thoracic Fractures
Posterolateral Approach: Transpedicular Corpectomy (Fig. 15.11)
a
b Fig. 15.11 Sagit tal CT reconstructions of an 18-year-old woman who was involved in a motorcycle accident, sustaining thoracic fracture dem onstrating (a) T6 and (b) T10 burst fractures with kyphotic angulation. (a) In addition, at the T5-6 level she had a fracture-dislocation with T5 laminar and spinous process fractures. The patient was able to move her lower extremities with some sensation. However, due to the fact that she had grossly unstable spine, she was kept on bedrest until surgical stabilization could be performed.
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Removal of Facet Complex (Fig. 15.12)
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Figure
Procedural Steps
Pearls
Fig. 15.12
After pedicle screw placement, a single rod contralateral to the side of surgical approach is placed to stabilize the spine during the corpectomy. The muscular and tendinous attachments need to be removed w ider than w ith a laminectomy. Remove tissue using monopolar cautery out to the edge of the facet complex and rib head.
• Prior to perform ing the corpectomy, the spine will need to be stabilized to prevent stretching, torque, or translocation.
15 Classi cation and Treatm ent of Thoracic Fractures
Drill (Fig. 15.13)
Figure
Procedural Steps
Fig. 15.13
Using a high speed drill, remove the facet complex, lamina, pars interarticularis, and pedicle on the side of the chosen approach. The neurovascular complex is ligated. The exposure should be from the pedicle of the level above to the pedicle of the level below.
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Corpectomy and Diskectomy (Fig. 15.14)
254
Figure
Procedural Steps
Pearls
Fig. 15.14
The corpectomy is done w ith a combination of drilling and using the Kerrison rongeur (1). Use curette to scrape disk material o the endplate (2). Remove the disk w ith a pituitary.
• Use uoroscopy to check depth often so as not to overshoot the depth of the vertebral body.
15 Classi cation and Treatm ent of Thoracic Fractures
Rib Head Trap Door Osteotomy (Fig. 15.15)
Figure
Procedural Steps
Pearls
Fig. 15.15
Partially cut through the rib head until the deep surface becomes thin enough to bend. When this is achieved, the spacer can be slid past the rib head for placement. Size the distance from the rostral to caudal endplates of the levels above and below. Then insert the spacer lateral to the thecal sac taking care not to put any pressure on the cord.
• Expandable titanium cages, nonexpendable graft, cadaveric fem ur, and other implants are all possibilities following corpectomy. Regardless of option, fusion across a corpectomy is often hindered by the long distances that the fusion needs to occur. Therefore, additional m easures m ust be taken to ensure adequate stabilization.
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Pedicle Screw s (Fig. 15.16)
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Figure
Procedural Steps
Fig. 15.16
Insert the remaining pedicle screw s on the operative side then t and lock in a second rod.
15 Classi cation and Treatm ent of Thoracic Fractures
Anterior Approach: Transthoracic Vertebrectomy (Fig. 15.17a, b)
a
b Fig. 15.17 (a) Sagit tal CT and (b) MRI images of a 38-year-old man who was riding on a monster truck at a rally when he crashed, sustaining a T12 burst fracture with spinal cord injury. The imaging shows retropulsion of the T12 vertebral body with approximately 50% canal compromise with a conus injury and cord signal changes. There was also associated kyphotic deformit y.
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Transthoracic Vertebrectomy Positioning and Approach Planning (Fig. 15.18)
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Figure
Procedural Steps
Pearls
Fig. 15.18
The patient is positioned in the lateral decubitus position. An axillary role is placed to prevent injury to the brachial plexus. The dependent leg is bent forw ard and the upper leg is supported on pillow s. A dual lumen endotracheal tube is used so that the dependent lung is ventilated and the superior lung, ipsilateral to the lesion, is collapsed. A w ide area is included in the prep to allow exposure of the entire thoracic spine and ipsilateral rib cage. The table is elevated under the patient’s chest to spread the ribs on the ipsilateral side.
• The patient m ust be intubated with a double lum en endotracheal
T1 to T4 can be approached anteriorly utilizing resection of the third rib. The incision w ill follow the medial border of the scapula and extend caudally. The incision w ill end at the sternocostal junction of the third rib. For levels T5 to T9, the rib above the level to be operated on is removed. For levels T10 to T12, the rib tw o levels above the level in question is removed.
• Often the lesion will determ ine the lateralit y but in cases of m idline
tube in order to allow single lung ventilation. This underscores the fact that the patient m ust be able to tolerate single lung ventilation for the procedure. If the patient has too m any com orbidities, then this approach m ay be rejected over a posterior approach. If direct lateral mini thoracotomy with specialized retractors is utilized, single lum en ventilation will su ce.
lesions or lesions that span the entire vertebral body, the vascular anatomy m ay dictate the approach. The position of the aorta needs to be reviewed on CT to determ ine if it will be in the way. The vena cava is t ypically m idline and rarely a ects the choice of left versus right. The aorta has a m ore variable position, but often surgery above T9 is best approached from the right. Below T9 the left side is an easier approach as the liver pushes up on the diaphragm on the right.
15 Classi cation and Treatm ent of Thoracic Fractures
Dissection (Fig. 15.19)
Figure
Procedural Steps
Fig. 15.19
The muscular layers are divided using electrocautery. The muscles transected are the trapezius, latissimus dorsi, then the rhomboids, and nally serratus. The rib is identi ed, dissected free, and resected. The neurovascular bundle is identi ed, ligated, and cut.
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Vertebrectomy (Fig. 15.20)
260
Figure
Procedural Steps
Pearls
Fig. 15.20
The vertebral body is removed w ith the drill and Kerrison rongeurs. The disks above and below are removed dow n the endplates. The thecal sac should be protected at all times if decompression is required.
• Remem ber that from T1 to T9 the rib articulates with the vertebral bodies of the corresponding thoracic level and the level above. Below T9, the rib articulates with the sam e thoracic level.
15 Classi cation and Treatm ent of Thoracic Fractures
Fusion and Instrumentation (Fig. 15.21a, b)
a
b
Figure
Procedural Steps
Fig. 15.21
(a) An appropriately sized spacer, either rib autograft, femoral allograft, or cage is inserted. (b) A plate and screw s are placed to provide rigid xation.
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Closing • Su rgical w ou n ds are closed in layers. • A drain is placed above the fascia to prevent hem atom a form ation. • Th e skin is closed w ith inverted 3-0 absorbable sut ures fol•
low ed by ben zoin an d adh esive st rips. An terior procedu res requ ire w ou n d closu re arou n d a ch est t ube to allow drain age from th e pleu ral space. A ch est t ube is p laced un der d irect visualizat ion . It can be placed directly on w ater seal if n o leak is suspected. Th e w oun ds are closed. A p ostoperat ive ch est X-ray is obt ain ed to ch eck for p n eu m oth orax or h em oth orax. Th e ch est t ube can be rem oved w h en out pu t is less th an 100 m L/day.
Postoperative Management • Pat ien t s sh ou ld be follow ed closely p ostop erat ively w ith n eurologic ch ecks. Th e acu it y of care w ill dep en d on th e exten t of th e surger y an d th e exten t of n eurologic com prom ise. Pat ien t s w ith m ore exten sive procedu res th at are at risk for m ore exten sive blood loss sh ou ld be obser ved overn igh t in th e in ten sive care un it .
Medication • Postop erat ive an t ibiot ics sh ou ld be adm in istered for 24 h ou rs or as long as th e drain is in place.
Radiographic Imaging • Postop erat ive
•
lm s sh ou ld be obtain ed to visu alize th e con st ru ct an d th e degree of realign m en t of th e spin e. Th is allow s com parison of th e fusion con st ruct during follow -u p (Figs. 15.22, 15.23, an d 15.24). If th e p at ien t h as any n ew sym ptom s or fails to im prove, th en m ore detailed im aging is in dicated su ch as MRI.
Further Management • Th e pat ien t sh ould h ave lim ited physical act ivit y w ith n o •
ben ding, lift ing, or t w ist ing un t il th e fusion h as h ad t im e for com plet ion , best visualized by postoperat ive X-ray or CT. After th at t im e, th en th e pat ien t m ay ben e t from physical th erapy to regain st rength .
a
b Fig. 15.22a, b Postoperative (a) AP and (b) lateral radiographs of the patient depicted in Figs. 15.1 and 15.2 underwent open reduction and T9 to T12 arthrodesis instrumentation using pedicle screws, rods, and a cross connector with in situ autograft, cancellous allograft 90 mL, and demineralized bone matrix 20 mL. He was fully recovered at his 1-year postoperative visit.
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15 Classi cation and Treatm ent of Thoracic Fractures
a
b Fig. 15.23a, b (a) Lateral and (b) AP radiographs of open reduction procedure in patient depicted in Fig. 15.11. This procedure included anterior T6 and T10 corpectomies using t wo titanium cages packed with in situ autograft. Also performed were T5 laminectomy, T6-7 decompression laminotomies, and T3-T11 arthrodesis—instrumentation using sublaminar hooks, pedicle screws, rods, and cross links, supplemented with in situ autograft, demineralized bone matrix, and cancellous allografts.
b
a Fig. 15.24a, b Postoperative (a) sagit tal and (b) coronal images of the same patient depicted in Fig. 15.17. He underwent a minimally invasive transthoracic transdiaphragmatic exposure from T11 to L1 and T12 corpectomy and decompression on spinal cord. T11 to L1 arthrodesis instrumentation was performed using an expandable titanium cage packed with in situ autograft, rib strut autograft, and thoracolumbar plate with screws.
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Special Considerations Posterolateral app roach es su ch as th e costot ran sversectom y an d lateral ext racavit ar y ap proach es p rovide greater exposu re to th e lateral p or t ion of th e ver tebral can al an d th e an terolateral port ion of th e th oracic vertebral bodies. Costot ran sversectom y m ay be u sed in th e rem oval of t rau m at ic bon e fragm en t s or oth er foreign bodies in t raum a an d is u seful in cases w h ere a pat ien t m ay n ot tolerate a form al th oracotom y eith er du e to age or p u lm on ar y p ath ology. It is less u seful in cases w h ere th e an terior can al n eeds to be fu lly visu alized or for oth er m idlin e path ology. In costot ran sversectom y, th e pat ien t m ay be placed pron e, sem ip ron e, or in m odi ed lateral decu bit u s p osit ion . In t u bat ion w ith a double lum en –cu ed en dot rach eal t ube is again recom m en ded as p n eu m oth orax is a possibilit y. Th e ap proach sh ou ld be on th e side of th e inju r y, or if m idlin e, on th e righ t to avoid th e arter y of Adam kiew icz w h ich usually origin ates on th e left side bet w een T8 to L2. Th e in cision is m idlin e (som et im es w ith a T) or p aram ed ian w ith or w ith ou t a h ockey st ick rela xing in cision . If th e in cision is param edian , th e m uscles (t rapezius an d lat issim u s dorsi) are re ected m edially. Midlin e in cision s requ ire subperiosteal dissect ion s. Th e ribs to be rem oved are skeleton ized su bperiosteally. En t ran ce to a d isk sp ace requ ires exp osu re of th e in ferior rib (e.g., T9-T10 disk sp ace requ ires exposure of th e 10th rib). Th e art icu lat ion s th at m ust be addressed in clu de th e su perior an d in ferior costal facet an d t ran sverse cost al facet . Th e pleura is m obilized an d re ected from th e un derside th e rib an d an terolateral posit ion of th e spin e. Th e rib of in terest is th en t ran sected approxim ately 5 cm from th e rib h ead. Th e foram en can then be iden t i ed by follow ing th e n eu rovascular bu n dle t ravelling on th e in ferior surface of th e rib. Th e pedicles can th en be iden t i ed above an d below th e foram en w h ich can be resected to visu alize th e lateral th ecal sac. Th e pleu ral an d in tercost al m uscles are blun tly dissected aw ay from th e vertebral body. Bon e from th e lateral ver tebral body or disk m ay be rem oved as required w ith care n ot to dam age th e radicular arteries. On ce th e decom pression or diskectom y is com p lete, in st ru m en ted or n on in st rum en ted fusion m ay be con sidered based on path ology. Again , par t ial vertebrectom y m ay be ach ieved. Pleu ral tears are rep aired if p resen t an d ch est t ubes are used if n ecessar y. Th e lat e ral ext racavit ar y ap p roach is a m ore exte n sive p oste rolat e ral ap p roach w h ich again d oes n ot violat e t h e ch est cavit y. Th e p at ie n t is p lace d in a p ron e p osit ion . A h ockey st ick (m id lin e in cision cu r ve d 4 5 d egre es o m id lin e for 6 to 8 cm in t h e low e r p or t ion ) or p aram e d ian in cision (ce n t e re d ove r t h e lat e ral p arasp in al m u scles) can be u se d . A p lan e is d evelop e d b et w e e n t h e su p e r cial an d d e e p p arasp in al m u scles, an d a m yocu t an e ou s ap is lift e d o to exp ose t h e lat eral p arasp in al m u scles an d r ib cage. Th e p arasp in al m u scles are t h e n m ob ilize d from t h e r ib an d t ran sve rse p rocess. Th e r ibs, ligam e n t ou s at t ach m e n t s, an d associate d t ran sve rse p rocesses are t h e n re m ove d . Sim ilarly to ab ove, t h e n e u ro vascu lar b u n d le is isolat e d an d act s a gu id e for id e n t i cat ion of t h e resp e ct ive foram e n an d p e d icles. Th e re m ain d e r of exp osu re is com p let e d sim ilarly t o t h e ot h e r p oste rolate ral te ch n iqu es.
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References 1. Vialle LR, Vialle E. Th oracic sp in e fract u res. Inju r y 2005;36 Suppl 2:B65–72 2. Den is F. Th e th ree colu m n sp in e an d it s sign i can ce in th e classi cat ion of acu te th oracolum bar spin al injuries. Spin e (Ph ila Pa 1976) 1983;8(8):817–831 3. Magerl F, Aebi M, Ger t zbein SD, Harm s J, Nazarian S. A com p reh ensive classi cat ion of th oracic an d lu m bar injuries. Eur Spin e J 1994;3(4):184–201 4. Vaccaro AR, Leh m an RAJ, Hu rlber t RJ, et al. A n ew classi cat ion of th oracolum bar injuries: th e im por t an ce of injur y m orph ology, th e in tegrit y of th e p osterior ligam en tou s com p lex, an d n eu rologic st at us. Spin e (Ph ila Pa 1976) 2005;30(20):2325–2333 5. el-Kh ou r y GY, W h it ten CG. Trau m a to th e u p p er th oracic sp in e: an atom y, biom ech an ics, an d un ique im aging feat ures. AJR Am J Roen tgen ol 1993;160(1):95–102 6. Maim an DJ, Pin t ar FA. An atom y an d clin ical biom ech an ics of th e th oracic spin e. Clin Neu rosu rg 1992;38:296–324 7. Lou is R. Su rger y of th e Sp in e. New York: Sp ringer; 1983 8. W h itesid es TEJ. Trau m at ic kyp h osis of th e th oracolu m bar sp in e. Clin Orth op Relat Res 1977;(128):78–92 9. Boh lm an H. H. Treat m en t of fract u res an d d islocat ion s of th e th oracic an d lu m bar spin e. J Bon e Join t Su rg Am 1985;67(1): 165–169 10. An driacch i T, Sch u lt z A, Belyt sch ko T, Galan te J. A m odel for st u dies of m ech an ical in teract ion s bet w een th e h um an spin e an d rib cage. J Biom ech 1974;7(6):497–507 11. Sm ith JS, Bh at ia N. Th oracic sp in al st abilit y: d ecision m aking. In Patel V, Burger E, Brow n C, eds. Spin e Traum a: Surgical Tech n iques. Berlin : Springer, 2010: 213–228 12. An derson S, Biros MH, Reardon RF. Delayed diagn osis of th oracolum bar fract ures in m u lt iple-t raum a pat ien t s. Acad Em erg Med 1996;3(9):832–839 13. St an islas MJ, Lath am JM, Por ter KM, Alpar EK, St irling AJ. A h igh risk group for th oracolum bar fract ures. Inju r y 1998;29(1):15–18 14. van Beek EJ, Been HD, Pon sen KK, Maas M. Up p er th oracic sp in al fract ures in t raum a pat ient s - a diagn ost ic pitfall. Injur y 2000;31(4):219–223 15. Argen son C. Traitem en t des fract u res d u rach is d orso-lom baire ch ez l’adu lte. Cah iers d’en seignem en t de la SO FCOT Con feren ces …. 1984 16. Coh en MS, Blair…B. Th oracolu m bar com p ression fract u res. AM Levin e. 1998 17. Mu n t ing E. Su rgical t reat m en t of p ost-t rau m at ic kyp h osis in th e th oracolu m bar sp in e: in dicat ion s an d tech n ical asp ect s. Eu r Spin e J 2010;19 Suppl 1:S69–73 18. Sm ith MW, Reed JD, Facco R, et al. Th e reliabilit y of n on recon st ru cted com p u terized tom ograp h ic scan s of th e abdom en an d pelvis in detect ing th oracolu m bar sp in e inju ries in blu n t t rau m a pat ien t s w ith altered m en t al st at us. J Bon e Join t Surg Am 2009;91(10):2342–2349 19. Bracken MB, Sh epard MJ, Collin s W F, et al. A ran dom ized, con t rolled t rial of m ethylpredn isolon e or n aloxon e in th e t reatm en t of acute spin al-cord injur y. Result s of th e Secon d Nat ion al Acu te Spin al Cord Injur y St udy. N Engl J Med 1990;322(20): 1405–1411 20. Gern dt SJ, Rodrigu ez JL, Paw lik JW, et al. Con sequ en ces of h igh dose steroid th erapy for acute spin al cord inju r y. J Traum a 1997;42(2):279–284 21. Hu rlber t RJ, Hadley MN, Walters BC, et al. Ph arm acological th erapy for acu te sp in al cord inju r y in gu idelin es for th e m an agem en t
15 Classi cation and Treatm ent of Thoracic Fractures of acute cer vical spin e an d spin al cord injuries. Neurosurger y 2013;72[suppl 2]:93–105 22. McAfee PC, Yu an HA, Fredrickson BE, Lu bicky JP. Th e valu e of com pu ted tom ography in th oracolum bar fract ures. An an alysis of on e h un dred con secut ive cases an d a n ew classi cat ion . J Bon e Join t Su rg Am 1983;65(4):461–473
23. Rein h old M, Kn op C, Beisse R, et al. Operat ive t reat m en t of 733 pat ien t s w ith acute th oracolum bar spin al injuries: com preh en sive result s from th e secon d, prospect ive, In tern etbased m ult icen ter st udy of the Spin e St udy Group of th e Germ an Associat ion of Traum a Surger y. Eur Spin e J 2010;19(10): 1657–1676
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16
Thoracolumbar Fractures Michael Y. W ang and Brian Hood
Introduction Th e t ran sit ion zon e at th e th oracolum bar jun ct ion di ers bio m ech an ically from th e st i th oracic spin e to th e m obile lu m bar spin e. Th is zon e of t ran sit ion is related to th e loss of th e rib cage as w ell as th e ch anging orien tat ion of th e facet join ts. Becau se of th ese factors th is area is p ron e to t rau m at ic inju r y an d accou n t s for ap proxim ately u p to 50% of all vertebral body fract u res an d u p to 40% of all spin al cord inju ries.1,2 Man agem en t of th oracolu m bar fract u res is a con t roversial topic in con tem porar y spin e su rger y. Early su rger y for decom p ression an d st abilizat ion is gen erally accepted for pat ien t s w ith clear in st abilit y an d an in com plete n eu rologic inju r y. Advan t ages of su rger y in clu de a bet ter correct ion of deform it y th an closed redu ct ion an d bracing, an opport un it y to perform d irect or in d irect decom p ression of th e n eural elem en t s, decreased requ irem en t for extern al im m obilizat ion , an d few er com plicat ion s du e to prolonged recu m ben cy. Th e su rgical t reat m en t is m ore con t roversial for pat ien t s w ith m ild to m oderate d eform it y, w ith ou t n eu rologic de cit , an d residu al sp in al can al com p rom ise, an d th e ideal solu t ion rem ain s largely u n kn ow n .1,3–9
Classi cation Th e m ost com m on fract ure pat tern s at th e th oracolum bar jun ct ion in clude com pression fract ures, burst fract ures, exion -dist ract ion injuries, an d fract ure-dislocat ion s.
Denis Classi cation Compression Fractures Failu re of th e an terior colum n in exion /com pression A: Failure of th e superior an d in ferior en dplates B: Su p erior ver tebral en d plate failu re (m ost com m on t yp e of com pression fract ure) C: In ferior ver tebral en dplate failure D: Failu re of th e cen t ral vertebral body w ith less involvem en t of th e en dplate
Burst Fractures Com pression failure of th e an terior an d m iddle spin al colum n s A: Failure of both superior an d in ferior en dplates B: Su p erior en dp late failu re on ly (m ost com m on t ype of bu rst fract u re) C: In ferior en dplate failu re on ly
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D: Axial loading an d rot at ion al inju r y E: Axial loading an d lateral exion
Flexion-Distraction (Ch an ce): Prim ar y an terior force vector act ing along an axis of rotat ion located an terior to m iddle colum n . Th e p osterior an d m iddle colu m n s fail in ten sion an d th e an terior colu m n fails in ten sion or com pression depen ding on th e axis of rot at ion .
Fracture -Dislocation Results from violen t com plex sh earing force an d by de n it ion involves all th ree spin al colum n s. High est rate of com plete n eu rologic inju r y.
AO Thoracolumbar System (of Magerl) De n es th e m ajor m ech an ism of sp in al inju r y com p ression (A), dist ract ion (B), an d torsion (C) to in dicate in creasing inju r y severit y occu rring w ith in creasing grade of inju r y. Th ree grou p s exist w ith in each t ype (A1, A2, A3) an d each grou p is divided in to subgrou ps (A1.1, A1.2, A1.3). Th e classi cat ion is based on m orp h ological criteria. Th e categories are est ablish ed according to th e m ain m ech an ism of injur y, an d take in to con siderat ion th e progn ost ic aspect s of poten t ial h ealing. Th e t ypes are determ in ed by th e th ree m ost im por t an t m ech an ism s act ing on th e spin e: com pression , dist ract ion , an d axial torque. Th e t ype A is a ver tebral body com pression injur y; t ype B inju ries involve an terior an d posterior elem en t inju ries w ith dist ract ion s; an d t ype C lesion s refer to an terior an d posterior elem en t injuries w ith rot at ion con sisten t w ith axial rot at ion inju ries. Th e AO system is ver y com preh en sive an d good for describ ing fract ure pat tern s, but it is a vict im of it s com p reh en siven ess; it does n ot con sider n eu rologic st at u s, an d does n ot aid in decision m aking.10
Thoracolumbar Injury Classi cation and Severity Score (TCLIS) Th is system w as developed due to th e n eed for a classi cat ion system th at cou ld be u sed to p rogn ost icate th e n eed for su rgical in ter ven t ion . Th e system w as based on a review of th e existing literat u re as w ell as con sen sus opin ion from a m u lt in at ion al grou p of leading sp in al t rau m a su rgeon s. Th ree m ajor inju r y ch aracterist ics w ere de n ed: injur y m orph ology, n eurologic
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Thoracolum bar Fractures
Table 16.1 Thoracolumbar Injury Classi cation and Severity Score Injury characteristic
Quali er
Points
Injury morphology Compression
— Burst
1 11
Rotation/translation
—
3
Distraction
—
4
Intact
—
0
Nerve Root
—
2
Incomplete
3
Complete
2
—
3
Intact
—
0
Suspected/Indeterm inate
—
2
Disrupted
—
3
Neurologic status
Spinal cord, conus m edullaris Cauda equine Posterior ligam entous complex integrit y
1 5 1 additional point given to morphology
st at u s, an d in tegrit y of th e p osterior ligam en tou s com plex (PLC) (see Table 16.1). Severit y score: A score of . 4 suggests a n eed for surgical t reat m en t becau se of sign i can t in st abilit y, w h ereas a score , 4 suggests n on surgical m an agem en t . A pat ien t w ith a score of 4 m ay be t reated su rgically or n on su rgically.5,11–13
Indications • Grossly u n st able inju ries w ith or w ith ou t n eurologic de cit • To facilit ate n eurologic recover y via direct decom pression or • • •
in direct decom pression th rough ligam en totaxis To correct deform it y To provide im m ediate st abilizat ion To decrease requirem en t s for extern al im m obilizat ion , an d com plicat ion s due to prolonged im m obilizat ion
Preprocedure Considerations Radiographic Imaging • An teroposterior (AP) an d lateral radiograph s of th e cer vical,
•
th oracic, an d lum bar spin e are stan dard im aging st udies follow ing spin al t rau m a. In som e cen ters th is h as been largely rep laced for su r vey purposes by w h ole body com puted tom ograp hy (CT) scan n ing. Becau se th ere is a h igh p ercen t age of n on con t igu ou s associated sp in al fract u res, en t ire n euraxis im aging m ay be w arran ted if clin ical su spicion is h igh .
Fig. 16.1 Sagit tal reconstruction of trauma CT scan showing fractures of T12 and L1 in a 55-year-old man who had fallen from a height.
• CT is gen erally th e n ext step after p lain lm s. Axial n e cu ts •
an d sagit t al recon st ru ct ion h elp de n e fract u re p at tern s an d determ in e th e degree of can al com pression (Fig. 16.1). Magn et ic reson an ce im aging (MRI): Gen erally n ot requ ired in a n eurologically in t act pat ien t in th e acu te set t ing, bu t can h elp evaluate th e PLC. With a n eurologic de cit , MRI is recom m en ded to iden t ify any ongoing spin al com p ression , evalu ate cord an atom y, an d ru le ou t ep idu ral h em atom a.
Medication (Neuroprotection and Nonoperative Management) • According to th e secon d NASCIS t rial, in p at ien t s w ith con rm ed spin al cord inju r y, p at ien ts st ar ted on m ethylp redn isolon e w ith in 3 h ou rs of inju r y h ad a su bstan t ial ben e t in
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•
term s of ult im ate n eurologic recover y. We do n ot use steroids at ou r in st it u t ion . Recen t pu blish ed gu idelin es do n ot recom m en d steroid u sage.14 In t raven ous uid, colloid, an d vasopressors are u sed as n eeded to m ain tain a m ean arterial pressu re of 85 m m Hg or greater.15
Surgical Management Th e goals of surgical t reat m en t in clude: (1) decom pression of th e spin al can al an d n er ve root s to facilit ate n eurologic recover y, (2) restorat ion an d m ain ten an ce of ver tebral body h eigh t an d align m en t to m in im ize post t rau m at ic deform it y, (3) ob tain ing rigid xat ion to facilitate n ursing care an d allow early m obilizat ion , (4) obtain ing a solid ar th rodesis of dam aged segm en ts or fract u re h ealing, an d (5) lim it ing th e n u m ber of in st ru m en ted vertebral m ot ion segm en ts. Surgical algorith m s can gen erally be classi ed in to on e of ve grou ps: (1) posterior decom pression an d st abilizat ion , (2) costot ran sverse/lateral ext racavitar y/t ran spedicular decom pression an d recon st ruct ion / stabilizat ion , (3) an terior corp ectom y/st abilizat ion , (4) com bin ed an terior/posterior decom pression /st abilizat ion (360), an d (5) p ercu t an eou s fract u re xat ion .
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Post e r ior ap p roach es allow for realign m e n t of t h e sp in e, d ire ct an d in d ire ct d e com p ression of t h e n e u ral ele m e n t s, an d p rot e ct ion again st lat e d efor m it y an d in st ab ilit y. Sp in al can al d e com p ression via ligam e n t ot a xis is op t ion ally ach ieve d w it h in t h e first 2 to 4 d ays p ost in ju r y. We p refe r to st ab ilize t h oracolu m bar fract u res w it h in 48 h ou rs of p re se n t at ion if m e d ically st able. For t h ora cic inju r ies, a p ost e rolat e ral, e it h e r cost ot ran sve rse ctom y or t ran sp e d icu la r, ap p roa ch allow s som e d e com p ression of an t e r ior p at h ology an d allow s a circu m fe re n t ial fu sion t h rou gh a p ost e r ior on ly ap p roa ch . Th is ch apter addresses th e posterior approach , both open an d percut an eous.
Operative Field Preparation • Th e skin is clean sed w ith alcoh ol th en a betadin e scrub is • •
used. Altern at ively, alcoh ol an d ch lorh exidin e can be u sed. Th e au th ors u se van com ycin an d ceft riaxon e for an t ibiot ic prophylaxis provided th e pat ien t does n ot h ave ren al failure or oth er con t rain dicat ion s.
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Operative Procedure Open Approach Positioning (Fig. 16.2)
Figure
Procedural Steps
Pearls
Fig. 16.2
The patient is positioned carefully on a radiolucent frame to obtain optimal preoperative reduction of deformity.
• A four-posted spinal table is used. Preincision uoroscopy veri es abilit y to visualize pedicles radiographically after exposure. One can conduct an awake turn or perform neurom onitoring with pre and post turn electromyography (EMG)/som atosensory evoke potentials (SSEPs) in patients with incomplete neurologic injury.
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Exposure (Fig. 16.3a, b)
a
b
270
Figure
Procedural Steps
Pearls
Fig. 16.3
(a) A midline posterior approach is most common for thoracolumbar instrumentation. (b) Subperiosteal exposure of the posterior elements is carried out laterally over the tips of the transverse processes.
• Instrum entation requires a wider exposure for optim al placem ent of instrum entation. Inadequate exposure risks screw malposition.
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Thoracolum bar Fractures
Decompression (Fig. 16.4)
Figure
Procedural Steps
Pearls
Fig. 16.4
The lamina is removed w ith a drill and rongeurs. At this point a costotransversectomy, or a transpedicular vertebrectomy, can be performed if indicated (see Chapter 15).
• Lam inectomy alone as a decompressive •
Ligamentotaxis may be used to mobilize anterior fracture fragments aw ay from the spinal cord. Alternatively, a dow nw ard directed curette can be used to tamp bone fragments anteriorly aw ay from the spinal cord (a rrow). This technique may be facilitated by removing the pedicle on one or both sides to achieve more exposure of the superior endplate, w hich is typically the area of greatest impingement.
procedure has been shown to be ine ective in achieving anterior spinal cord decompression. The only indication for a standalone lam inectomy is to evaluate for dural tears or posterior compression.
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Facetectomy and Pedicle Cannulation (Fig. 16.5a–c)
a
272
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Thoracolum bar Fractures
c
b
Figure
Procedural Steps
Pearls
Fig. 16.5
(a) The facet joint is stripped of its capsule. The inferior portion of the inferior facet is removed w ith a rongeur or osteotome. Partial facetectomy should reveal a pedicle “blush.”
• Rem oving the inferior portion of
(b) At T12 the starting point is the junction of the bisected transverse process and border of the lateral pars. The starting point trends medially and cephalad as one moves cranially tow ard the midthoracic region.
•
A thoracic (blunt, curved) probe is placed in the “blush” or starting point as determined by AP uoroscopy. The curve is directed laterally and advanced 15 to 20 mm letting the probe “fall into” the pedicle. (c) After advancing 15 to 20 mm, the probe is removed and replaced facing medially and advanced to a depth of 30 to 40 mm in the midthoracic spine. A feeler/sounder probe is then introduced. Only blood should return from the tract and not cerebrospinal uid. A oor and then four w alls should be palpated.
•
the inferior facet allows m ore soft tissue rem oval and helps to nd the entrance to the pedicle. Anatom ic starting points can be veri ed with AP uoroscopy and pedicle m arkers can be placed. Lateral uoroscopy can then be used for pedicle cannulation. Any abrupt step o when cannulating the pedicle should raise suspicion of a pedicle breach and should be investigated with a sounding probe and radiographic evaluation. Pay at tention to the medial portion of the tract where violations of the pedicle are critical.
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Tapping and Screw Placement (Fig. 16.6)
274
Figure
Procedural Steps
Pearls
Fig. 16.6
The pedicle is then under-tapped 0.5 mm. Preoperative assessment of pedicular size guides the appropriate tapping and screw placement (1). After tapping, the tract is once again sounded w ith a feeler probe searching for violations. Slow screw placement allow s utilization of viscoelastic properties of the pedicle and avoids pedicle fracture (2).
• Charting pedicle size and depth preoperatively •
facilitates appropriate screw selection. All screws placed should be veri ed by intraoperative imaging. In addition, electrodiagnostic testing can be perform ed with abdom inal leads.
16
Thoracolum bar Fractures
Rod Placement (Fig. 16.7a–c)
a
b
Figure
Procedural Steps
Pearls
Fig. 16.7
A rod is selected and contoured appropriately. Distraction and reduction maneuvers can be applied to aid in reduction of compression via ligamentotaxis.
• The rod should be passed approxim ately 5 m m beyond
c
the m ost cranial and caudal screw. Compression maneuvers gain lit tle in achieving additional rod length.
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II Spinal Em ergency Procedures
Bone Grafting (Fig. 16.8)
276
Figure
Procedural Steps
Pearls
Fig. 16.8
Spinous processes and lamina local autograft removed are morselized. The remaining lamina, transverse process, and facets are decorticated w ith a high speed drill (1). The bone graft is then laid on bleeding bone (2). Iliac crest bone autograft remains the gold standard.
• Intraoperative relaxation of retractors periodically facilitates blood ow and preservation of extensor m usculature. Careful preservation of regional blood supply supports rapid graft incorporation and focuses on fusion versus construct failure.
16
Thoracolum bar Fractures
Percutaneous Approach Positioning and Pedicle Targeting (Fig. 16.9a–c)
b
c
a
Figure
Procedural Steps
Pearls
Fig. 16.9
(a) The patient is carefully positioned prone on a radiolucent table, as in Fig. 16.2, in order to obtain the best preoperative reduction of deformity. (b) Prior to prepping and draping, the pedicles are targeted using AP uoroscopy. (c) K w ires are placed at the 9 o’clock position on the left sided pedicles and the 3 o’clock position of the right pedicles. These lines are marked on the patient. We also mark the mid pedicle levels in the horizontal plane at each level.
• A good AP im age is imperative. The endplates must be absolutely parallel, and the spinous process equidistant bet ween the pedicles. At each level, it is helpful to m ark the degree of rotation of the C-arm needed to obtain the view. This help to decrease uoroscopy tim e, as well as operative tim e.
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Jam Shidi Placement (Fig. 16.10a–c)
a
278
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Thoracolum bar Fractures
c b
Figure
Procedural Steps
Pearls
Fig. 16.10
(a) The bone trephine needle is started in the skin just lateral to the marked pedicle and advanced to the starting point (3 o’clock on the right, 9 o’clock on the left). Once bone is encountered, an image is obtained. The needle is lightly malleted to engage the tip into the cortical bone (1). A mark is made on the needle approximately 25 mm from the skin surface (2). The needle is then advanced into the pedicle approximately 15 mm. An image is taken. (b) If the needle has traversed less than 50%the w idth of the pedicle, it can be safely advanced the remained of the distance w ithout fear of medial w all breech.
• We use AP im ages to place the bone trephine needles. Alternatively, the needles can be advanced to 20 m m under AP im aging, and then switched into a lateral view to advance the rem ainder of the distance into the vertebral body (c).
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Guidew ire Placement (Fig. 16.11a, b)
a
b
280
Figure
Procedural Steps
Pearls
Fig. 16.11
(a, b) The stylet is removed from the bone trephine needle and a K w ire is placed (1). The K w ire is advanced several mm beyond the bone trephine needle and then the needle is removed (2).
• The K wire can be used as a exible “feeler” probe to ensure that bone is encountered when advancing.
16
Thoracolum bar Fractures
Facet Fusion (Optional) (Fig. 16.12)
Figure
Procedural Steps
Pearls
Fig. 16.12
If a long-term fusion is required, dilators are then placed over the K w ire and docked on the pedicle screw starting point. A tubular retractor is then placed (1). The facet is superior and medial to the starting point. The soft tissue is then removed w ith electrocautery, and the facet decorticated w ith a high speed bur (2). Bone graft is then laid on the facet.
• The necessit y for fusion is decided on an individual basis.
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Screw Placement (Fig. 16.13a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 16.13
If a facet fusion is not performed, next make a 15 mm skin incision about the K w ires. (a) A dilator is passed to open the fascia, and docked at the starting point. The inner cannula of the dilator is removed (1). An aw l is placed over the K w ire to enhance the starting point for the tap (2). Next, the C-arm is brought into lateral position.
• It is imperative to m aintain control of
(b) We tap the pedicle under lateral imaging (1). At this point, the tap can be stimulated to assess for a medial pedicle breach. The tap is removed w ith care to not dislodge the K w ire. A cannulated screw w ith a screw extension is then advanced (2). Several images are taken as the screw is advanced. It is important to not advance the K w ire w ith the screw. The K w ire is then removed.
282
•
the K wire at all tim es. If the K wire is inadvertently rem oved, it is best to switch back to AP im aging to try to replace the wire. If unable, it is possible to try to replace the bone trephine needle without the st ylet. We t ypically under tap for traum a cases. Try to keep the position of the screw heads the sam e for all screws to facilitate passage of the rod.
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Thoracolum bar Fractures
Rod Placement and Deformity Correction (Fig. 16.14a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 16.14
(a) A rod is measured and cut. It is extremely important that the rod is passed subfascially w hen inserted into the rst screw head. (b) Through a cantilever approach, deformity correction occurs as the rod is locked into place (1). A derotation device is used and the screw caps are nal tightened (2). The extended tabs are then removed (3). If the tabs are inadvertently removed prior to passing the rod, a rod can still be placed, but it makes rod placement very di cult.
• It is important to leave the rods on the rod holders until all the caps have been applied. Minim al distraction and compression can be perform ed with the m inim ally invasive system ; therefore, positioning is imperative.
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Closing Open Approach For th e open approach , m et iculous h an dling of th e exten sor m u scu lat u re follow ed by a t igh t fascial closu re im proves th e m u scles’ abilit y to p rom ote sagit t al balan ce an d ap prop riate skelet al loading. Th e w ou n d is closed in su ccessive layers (deep fascia, su p er cial fascia, th en skin ) u sing resorbable su t u re.
Percutaneous Approach • For th e percut an eou s approach , th e in dividual st ab w ou n ds
• • •
are irrigated w ith an t ibiot ic im p regn ated salin e. Lit tle bleeding is en cou n tered due to a t am p on ade e ect from th e dilators an d screw exten sion s. Th e fascia is reapproxim ated w ith in terrupted 2-0 resorbable su t u res. Th e skin is closed w ith a 3-0 m ono lam ent , resorbable sut ure. Fin al AP an d lateral im ages are obtain ed w ith C-arm u oroscopy before th e w oun d is closed.
Postoperative Management Monitoring
Fig. 16.15 Lateral X-ray of patient depicted in Fig. 16.1 showing posterior rod construct and vertebroplasties at T12 and L1 to add structural support.
• Th e level o f ca re is d ict at e d by t h e com or b id co n d it ion s of t h e p at ie n t s. For p at ie n t s w it h a p a u cit y of ot h e r in ju r ie s, w e t yp ica lly obse r ve t h e m ove r n igh t in a st e p d ow n u n it .
Medication • It is ou r pract ice to place p at ien t s on a p at ien t-con t rolled • • •
an algesia device w ith eith er m orp h in e or hydrom orp h on e in th e in it ial postoperat ive period. Pat ien t s are gradu ally t ran sit ion ed to oral m edicat ion on th e secon d or th ird p ostop erat ive day. We continue antibiotic prophylaxis for approxim ately 24 hours after surgery. We rout in ely start pat ien t s on deep vein th rom bosis prophylaxis w ith low m olecular w eigh t h ep arin on th e rst postop erat ive day if th ere are n o oth er bleeding con t rain dicat ion s.
Radiographic Imaging • We t ypically obtain uprigh t AP an d lateral im ages prior to •
disch arge (Fig. 16.15). Im aging is th en p erform ed at 3, 6, an d 9 m on th s postoperat ively.
Special Considerations • The optim al surgical approach and treatm ent of unstable thoracolum bar spine injures are poorly de ned because of a lack of w idely accepted level I clinical literature. When treating
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•
•
patients w ith thoracolum bar fractures, the surgeon m ust rst decide if the injury requires an operation. If an operation is required, a decision m ust be m ade w hether a decom pression is warranted in addition to stabilization. A decision m ust be m ade as to w hether the surgical goals can best be accom plished via an anterior, posterior, or com bined approach. We gauge the length of our construct based on the degree of instabilit y. In m ost instances we xate two levels above and t wo below. For burst fractures it is possible to perform a cem ent augm entation of the fractured level (vertebroplast y or kyphoplast y; see Fig. 16.15). Short pedicle screw s can also be placed into the fractured level, thus allow ing som e cases to be instrum ented only one level above and below the fracture. The thoracic segm ents are relatively im m obile so sacri cing m otion segm ents is biom echanically irrelevant. Lengthening the construct distally into the lum bar spine has di erent biom echanical considerations and should be individualized on a per patient basis. Rem oval of percut an eou s in st rum en tat ion m ay be required if an in tersegm en t al fu sion is n ot perform ed as th e su ccess of th e surger y w ill require fusion of th e prim ar y fract u re. Based on literat ure from th e AO Fixateu r In tern e, rem oval is perform ed t ypically 12 m on th s p ostop erat ive an d after radiograp h ic eviden ce of fu sion .16–21
References 1. Vaccaro AR, Leh m an RA Jr, Hu rlber t RJ, et al. A n ew classi cat ion of th oracolum bar injuries: th e im por t an ce of injur y m orph ology, th e in tegrit y of th e posterior ligam en tou s com p lex, an d n eu rologic st at us. Spin e 2005;30(20):2325–2333
16 2. Dai LY, Jiang SD, Wang XY, Jiang LS. A review of th e m an agem en t of th oracolum bar bu rst fract ures. Surg Neurol 2007;67(3): 221–231, discussion 231 3. Th om as KC, Bailey CS, Dvorak MF, Kw on B, Fish er C. Com parison of operat ive an d n on operat ive t reat m en t for th oracolum bar burst fract ures in pat ien t s w ith ou t neurological de cit: a system at ic review. J Neurosurg Spin e 2006;4(5):351–358 4. Verlaan JJ, On er FC. Operat ive com pared w ith n on op erat ive t reat m en t of a th oracolum bar burst fract ure w ith out n eurological de cit . J Bon e Join t Surg Am 2004;86-A(3):649–650, auth or reply 650–651 5. Vaccaro AR, Lim MR, Hu rlber t RJ, et al; Sp in e Trau m a St u dy Grou p . Su rgical d ecision m akin g for u n st able t h oracolu m bar sp in e inju r ies: resu lt s of a con sen su s p an el review by t h e Sp in e Trau m a St u dy Grou p . J Sp in al Disord Tech 2006;19(1): 1–10 6. Siebenga J, Leferin k VJ, Segers MJ, et al. Treat m en t of t rau m at ic th oracolu m bar sp in e fract u res: a m u lt icen ter p rospect ive ran dom ized st u dy of op erat ive versu s n on su rgical t reat m en t . Sp in e 2006;31(25):2881–2890 7. Hear y RF, Salas S, Bon o CM, Ku m ar S. Com p licat ion avoidan ce: th oracolu m bar an d lu m bar bu rst fract u res. Neu rosu rg Clin N Am 2006;17(3):377–388, viii 8. Harris MB, Sh i LL, Vacarro AR, Zd eblick TA, Sasso RC. Non su rgical t reat m en t of th oracolum bar spin al fract ures. In st r Course Lect 2009;58:629–637 9. Dai LY, Jiang LS, Jiang SD. Con ser vat ive t reat m en t of th oracolu m bar bu rst fract ures: a long-term follow -up result s w ith special referen ce to th e load sh aring classi cat ion . Spin e 2008;33(23): 2536–2544 10. Magerl F, Aebi M, Gert zbein SD, Harm s J, Nazarian S. A com preh en sive classi cat ion of th oracic an d lum bar injuries. Eu r Spin e J 1994;3(4):184–201 11. Patel AA, Vaccaro AR. Th oracolu m bar sp in e t rau m a classi cat ion . J Am Acad Or th op Su rg 2010;18(2):63–71
Thoracolum bar Fractures
12. Joaquim AF, Fernandes YB, Cavalcante RA, Fragoso RM, Honorato DC, Patel AA. Evaluation of the Thoracolum bar Injury Classi cation System in Thoracic and Lum bar Spinal Traum a. Spine 2011;36: 33–36 13. Alan ay A, Acaroglu E, Yazici M, Surat A. Th oracolum bar spin e fract u res. Sp in e 2001;26(7):840–841 14. Hurlbert RJ, Hadley MN, Walters BC, et al. Ph arm acological th erapy for acute spin al cord injur y. Neurosu rger y 2013;72 (Su p pl 2):93–105 15. Vale FL, Burn s J, Jackson AB, Hadley MN. Com bin ed m edical an d surgical t reat m en t after acute spin al cord injur y: result s of a prospect ive pilot st udy to assess th e m erit s of aggressive m edical resuscit at ion an d blood pressu re m an agem en t . J Neurosurg 1997;87(2):239–246 16. Faun dez AA, Taylor S, Kaelin AJ. In st r um en ted fusion of th oracolum bar fract ure w ith t ype I m in eralized collagen m at rix com bin ed w ith autogen ous bon e m arrow as a bon e graft su bst it ute: a four-case report . Eu r Spin e J 2006;15(Suppl 5):630–635 17. Dick W, Kluger P, Magerl F, Woersdörfer O, Zäch G. A n ew device for in tern al xat ion of th oracolu m bar an d lu m bar sp in e fract u res: th e ‘ xateu r in tern e’. Parap legia 1985;23(4):225–232 18. Ben ce T, Sch reiber U, Grupp T, Stein h auser E, Mit telm eier W. Tw o colum n lesions in the th oracolum bar jun ct ion : an terior, posterior or com bin ed approach ? A com parat ive biom ech an ical in vit ro invest igat ion . Eur Spin e J 2007;16(6):813–820 19. Dai LY, Jiang LS, Jiang SD. Posterior sh or t-segm en t xat ion w ith or w ith out fusion for th oracolum bar burst fract ures. a ve to seven -year prospect ive ran dom ized st udy. J Bon e Join t Surg Am 2009;91(5):1033–1041 20. Haiyun Y, Rui G, Sh u cai D, et al. Th ree-colum n recon st r uct ion th rough single p osterior app roach for th e t reat m en t of u n st able th oracolu m bar fract u re. Sp in e 2010;35(8):E295–E302 21. Katonis P, Pasku D, Alpan taki K, et al. Com binat ion of the AOMagerl an d load-sh aring classi cat ion s for th e m an agem en t of th oracolu m bar burst fract ures. Or th opedics 2010;33(3):158–163
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Spinal Epidural Compression Asha Iyer and Arthur Jenk ins
Introduction Non t rau m at ic spin al epidu ral com p ression can resu lt from several di eren t en t it ies, bu t acu te deteriorat ion alm ost alw ays occurs as a result of a few con dit ion s, th ree of w h ich are h igh ligh ted in th is ch apter: spon t an eou s epidural h em atom a, spin al ep idu ral abscess, an d m et astat ic ep idu ral spin al cord com p ression syn drom e.
Incidence Spontaneous Spinal Epidural Hematoma Sp in al ep idu ral h em atom as (SEHs) are a rare cau se of sp in al cord com pression . How ever, th ey con st it ute th e m ajorit y (u p to 75%) of spin al h em atom as. Th e peak in ciden ce occurs in pat ien ts in th eir sixth decade of life, th ough a secon d peak is seen in adolescen ts bet w een 15 an d 20 years of age. A m ale predom in an ce h as frequ en tly been docu m en ted.
Spinal Epidural Abscess Sp in al ep idu ral abscesses (SEAs) are an in frequ en t cau se of spin al cord com p ression , rep resen t ing 0.2 to 2 p er 10,000 h osp it al adm ission s. Th e m ajorit y of a ected pat ien t s are bet w een 30 an d 60 years old, th ough th ey span a w ide range from n eon ates to geriat ric. A m ale p red om in an ce—ap p roxim ately t w ice as com m on as in w om en —exists. Risk factors in clu d e diabetes m ellit us, en d-stage ren al disease, HIV or oth er im m un ecom prom ised st ates, in t raven ou s (IV) drug use, an d alcoh olism . Local factors addit ion ally in clu de sp in e su rger y or t rau m a, an d cath eter placem en t in to th e ver tebral can al. W h ile n early on e-th ird of a ected pat ien t s died at th e begin n ing of th e t w en t ieth cen t u r y, th e m ort alit y is n ow less th an h alf of th at n u m ber given im p rovem en t s in an t ibiot ic th erapy an d su rgical tech n iqu e. Corresp on dingly, th e p ercen t age of p at ien t s w ith eith er com plete recover y or on ly m in or residu al n eu rologic de cit h as m ore th an dou bled.1
Metastatic Epidural Spinal Cord Compression In th e Un ited St ates, th ere are 1.4 m illion n ew cases of can cer an n u ally an d ever y year over h alf a m illion can cer p at ien ts su ccum b to m et astat ic disease. Th e skelet al system ser ves as th e th ird m ost com m on site of m et ast at ic spread (after pu lm on ar y an d h epat ic), an d w ith in th e skelet al system th e sp in al colu m n is m ost frequ en tly a ected.
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Cu rren t est im ates based on p ost m or tem st u d ies im ply 30– 90% of can cer pat ien t s (large variabilit y depen ding on prim ar y) w ill h ave m etast at ic spin al disease. A tot al of 5 to 10% of can cer pat ien t s have m et astat ic epidural spin al cord com pression (MESCC), w ith th is propor t ion in creasing to 40% in th ose w ith other, n on spin al bony m et ast ases. Th ese n um bers t ran slate in to 25,000 cases of sym ptom at ic MESCC per year, an in ciden ce th at is rising as an t in eoplast ic th erapies evolve an d life expect ancies in crease. MESCC is an epidural lesion causing t ru e displacem en t of th e spin al cord from it s n orm al p osit ion in th e spin al can al.
Etiologies Spinal Epidural Hematoma Sp on t an eou s SEH can be divided in to t rau m at ic an d n on t rau m at ic. Cau ses of t rau m at ic SEH in clu de lu m bar p u n ct u re or ep idu ral an esth esia, fract u re, spin al su rger y, p hysical exert ion , bir th t raum a, an d ch iropract ic m an ipu lat ion . Causes of spon t an eous SEH in clu de h em orrh age from an arterioven ous m alform at ion (AVM), h em angiom a, or t u m or. In u p to 30% of cases, n o et iology is discern ed .2 Follow ing th ese idiopath ic cases, an t icoagulan t th erapy an d vascular m alform at ion s are m ost often im plicated. An t icoagulat ion or any bleeding diath esis is a risk factor for SEH.3
Spinal Epidural Abscess In fect ion can sp read h em atogen ou sly or con t igu ou sly. Any dist an t site of in fect ion can spread h em atogen ou sly; h ow ever, skin an d soft t issu e in fect ion s rep resen t th e m ost com m on sou rces. SEAs arising in th is fash ion gen erally d evelop in th e p osterior ep idu ral sp ace. SEAs th at sp read by direct exten sion pred om in an tly origin ate from a vertebral body focu s, or less com m on ly from adjacen t soft t issu e. Th is vector of sp read u su ally involves th e an terior aspect of th e spin al can al. In ocu lat ion can also occu r iat rogen ically. In a large m et aan alysis of over 900 cases, ep id u ral an est h esia or an algesia w ere associated w it h a 6% rate of in fect ion , an d invasive p roced u res, eit h er sp in al or ext ra-sp in al, w it h 14–22%.4 Usu ally a severe pyogen ic in fect ion w it h Staphylococcus aureus is t h e m ost com m on cau sat ive agen t . St reptococcus sp ecies an d coagu lase-n egat ive Staphylococcus follow in frequ en cy. Gram n egat ive rod s su ch as Pseudom onas an d Escherichia coli, accou n t for a sm all fract ion , being m ore p revalen t w it h IV d r ug u se. Fin ally, Mycobacterium t uberculosis, fu n gal sp ecies, an d p arasit ic organ ism s are rare except for im m u n e-com p rom ised st ates.
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MESCC Met a st at ic d isease sp read s to e p id u ral sp ace in t w o w ays: (1) d ire ct ly in t o t h e sp in a l can al t h rough in t e r ve r t ebral fo ram e n from a p arave r t eb ral m ass (1 5 % of m et ast at ic cord com p ression ); an d (2 ) t h e re m ain in g 8 5% from h e m at oge n ou s sp read (h ist or ica lly t h ough t via Bat son ’s p lexu s, n ow b elieve d t o be m ore likely a r t e r ia l) t o t h e ve r t ebral bod y, from w h e re t h e lesion grow s p ost e r iorly in to t h e e p id u ral sp a ce. Th ese m et ast at ic lesion s can cau se b on e e rosion , p at h ologic fra ct u res, a n d ext r u sion of b on y fragm e n t s in t o can al, w h ich can all fu r t h e r com p ou n d can a l n a r row in g or cord com p ression .
Pathophysiology
Spinal Epidural Com pression
t ien t s of t h e 46- to 75-year-old year age grou p , t h e low er t h o racic an d lu m bar region s are m ost com m on , w it h a sm aller frequ en cy m a xim u m in t h e cer vical levels.8 A p ain -free in terval m ay occu r, bu t t h en is ge n erally follow ed by p rogression of n e u rologic d e cit ove r h ou rs to days tow ard accid p aresis or p legia.
Spinal Epidural Abscess Seven t y-on e p ercen t of p at ien t s p resen t w ith back pain as th e in it ial sym ptom ; 66% h ave fevers. Th is proceeds to radicular irrit at ion , w ith su bsequ en t n eu rologic d e cit s, in clu d ing m u scle w eakn ess, sen sor y dist u rban ces, an d sph in cter in con t in en ce. Progression to fran k paralysis occurred on ly in on e-th ird of p at ien ts.9
Spinal Epidural Hematoma
MESCC
Bleeding is gen erally th e resu lt of tearing of epidu ral vein s, alth ough tearing of epidu ral arteries or h em orrh age from a m alform at ion is also p ossible. Even in circu m st an ces involving an t icoagu lan t th erapy, oth er factors are posited to con t ribu te, in clu ding in creased pressure in th e in terior ver tebral ven ous p lexu s an d foci of vascular “decreased resist an ce.”
Pain (83–95%) is a com m on p resen t at ion . Local pain is th ough t to be related to periosteal st retch ing or local n eoplast ic in am m ator y p rocess. Th is p ain respon ds w ell to steroid s an d is w orse w ith recum ben cy. Mech an ical pain is pain th at is exacerbated by m ovem en t/act ivit y an d is often caused by path ologic fract ure or ver tebral body collapse, an d in dicat ive of spin al in stabilit y. Th is pain is recalcit ran t to steroids/n arcot ics; radicular p ain is th at w h ich involves n er ve root com pression an d usu ally con form s to a derm atom al dist ribut ion . Motor dysfu n ct ion is p resen t in 60–85% of p at ien ts an d is ch aracterized by w eakn ess an d long t ract sign s. Th ere are correlat ion s bet w een n eu rologic st at us at t im e of diagn osis (part icularly w ith respect to m otor fun ct ion ) an d progn osis from MESCC. Sen sor y loss is in close proxim it y to m otor n dings an d au ton om ic/sph in cter dysfu n ct ion is a later n ding, w ith bladder dysfun ct ion being th e m ost com m on . Th ough th e rate varies, p at ien t s w ith th ese de cits in evit ably progress to p aralysis w ith out in ter ven t ion .
Spinal Epidural Abscess As w ith any form of com pression , vascular com prom ise w ith con sequen t hypoxia h as been on e favored path ogen et ic exp lan at ion . How ever, in an im al m odels of S. aureus ep idu ral abscesses, even w h en SEAs cau sed para- or qu adrip legia, n o com pression of spin al arteries w as n oted,5 th u s su p port ing a p aram ou n t role for direct m ech an ical com pression .
MESCC Hyp ot h esized m ech an ism s by w h ich dam age occu rs in clu d e (1) direct com p ression t h at lead s to dem yelin at ion an d a xon al dam age; (2) vascu lar com p rom ise, w h ere occlu sion of ven ou s p lexu s p rom otes breakd ow n of cord–blood barr ier an d t h u s vasogen ic ed em a; an d (3) ter m in al ar ter ial occlu sion w it h isch em ia/in farct ion m ay follow lead ing to ir reversible dam age. Cer t ain au t h ors h ave hyp oth esized th at in p at ien t s rap id ly d eteriorat in g ar terial in farct ion m ay u n d erlie d eclin e w h ereas ven ou s congest ion m ay in it ially be m ore relevan t in p at ien t s w it h slow d eclin e.6 Th is disp ar it y m ay exp lain t h e w orse ou tcom e associated w it h a m ore rap id evolu t ion of m o tor w eakn ess.7
Presentation Spinal Epidural Hematoma SEH is u su ally acu te an d p rogressive, lead in g to p e r m an e n t n eu rologic d e cit if n ot m an aged im m ed iately. Sym p tom s con sisten t ly begin w it h severe back p ain in t h e locat ion of t h e h em or rh age, w it h or w it h ou t a rad icu lar com p on en t . Th e com m on segm en t al levels involve d var y by age; in t h e p a-
Indications Spinal Epidural Hematoma Most SEHs are located d orsal to t h e sp in al cord , w it h a large m et a-an alysis qu ot in g 75% in t h is sagit t al locat ion .8 Em ergen t or u rgen t d ecom p ression w it h in h ou rs is associated w it h bet ter ou tcom es. In t h e sam e m et a-an alysis, for p at ien t s w h o received t reat m en t w it h in 12 h ou rs of on set of sym ptom s, 66% recovered com p letely, 13% recovered w it h m ild resid u al n eu rologic d e cit , an d 13% con t in u ed to h ave severe im p air m en t or sh ow n o im p rovem en t . In con t rast , for p at ien t s w h ose t reat m en t w as in it iated 13–24 h ou rs after sym ptom on set , 64% h ad severe d e cit s or n o im p rovem en t , versu s 36% w it h su bst an t ial recover y. Th erefore, t h e t reat m en t of ch oice is im m ed iate d ecom p ression in t h ose p at ien t s t h at can tolerate su rger y. Asym ptom at ic p at ien t s w it h ou t n eu rologic d e cit can be con sid ered for obser vat ion , esp ecially in ch ild ren an d teen agers in w h ich a lam in ectom y m ay d est abilize t h e p oster ior colu m n .
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II Spinal Em ergency Procedures
Spinal Epidural Abscess Th e rst operat ive in ter ven t ion —a lam in ectom y—for SEA w as perform ed in 1892; after in creasing report s of successes, surger y becam e th e m ain stay of t reat m en t by th e 1930s. An early series 10 n oted th at SEA pat ien t s w ith out paralysis or w h ose p aralysis h ad developed less th an 36 h ours before th e operat ion h ad bet ter postoperat ive ou tcom es w ith respect to sur vival an d fu n ct ion . In con t rast , in p at ien ts w h ose p aralysis develop ed m ore than 48 h ou rs before su rger y, n on e recovered n eu rologic fu n ct ion ; all m ort alit ies in th e series w ere rep or ted in th is latter group. Th is correlat ion of outcom e w ith t im e to in ter ven t ion h as been rep eatedly con rm ed.11,12 Con ser vat ive t reat m en t is rarely in dicated: eith er for th ose w h o can n ot tolerate surger y, or w h o h ave large abscesses exten ding a con siderable length of th e spin al cord.
MESCC Con sen su s an d exper t opin ion s regarding in dicat ion s for surger y largely d erive from st u dies invest igat ing th e p rogn ost ic value of surgical in ter ven t ion given variou s pat ien t group at t ribu tes. Th e eviden ce dictat ing th e app ropriate approach to t um or decom pression h as evolved sign i can tly over th e past 50 years. Early t reat m en t un derscored in direct decom pression of th e ep idu ral sp ace via st raigh t lam in ectom y, follow ed by radiat ion th erapy (RT).13,14 How ever, later st u dies 15,16 dem on st rated n o advan t age for lam in ectom y, ren dering radiat ion alon e th e p referred th erap eu t ic st rategy for a p eriod of years. More recen t st u dies w ith m odern an esth et ic an d im aging tech n iqu es h ave led to a resu rgen ce of su rgical decom pression as p ar t of th e t reat m en t st rategy.6,17 A large ran dom ized con t rol t rial6 assessed decom pressive resect ion in conjun ct ion w ith RT versu s RT alon e. Criteria for st u dy in clu sion requ ired MESCC rest ricted to a single area; accept able surgical can didates w ith life expect an cy . 3 m on th s; on e n eurologic sym ptom (in clu ding pain ); n ot tot ally p araplegic for . 48 h ou rs. Radiosen sit ive t um ors an d sole root com pression or cau da equin a syn drom es w ere exclu ded; 84% of th e su rger y grou p versu s 52% of th e RT group w ere able to w alk after t reat m en t , 62% versus 19% regain ed am bu lat ion w h en ce lost , an d 94% versu s 74% rem ain ed am bulator y. Ad dit ion ally, th e st u dy revealed sign i can t d ifferen ces bet w een t reat m en t grou p s w ith resp ect to m ain ten an ce of con t in en ce; m u scle st rength ; fu n ct ion al abilit y; an d in creased sur vival (126 versu s 100 days), w ith am bulat ion an d con t in en ce persist ing for th e lifet im e of th e surger y group. Spin al in stabilit y can in depen den tly con tribu te to sym ptom s, by directly causing m echan ical injur y to the spinal cord. As RT is un likely to am eliorate spinal in st abilit y, su rger y m ay be m ore ap prop riate in th ese circu m stan ces. An an alysis focu sing on form s of com pression for patien ts w h o w ere, at th e on set , eith er in depen den tly am bulator y, assisted am bulator y, paraparet ic, an d paraplegic: w ith ou t bony com pression , post -RT am bulat ion rates w ere 100%, 94%, 60%, 11%, respectively. These rates dropped to 92%, 65%, 43%, and 14%, respectively, w hen all pat ients (w ith bony an d non bony com pression ) w ere considered.18 A com preh en sive literat ure review 19 suggested that w ith RT alon e, 36%subjects im proved w h ile 17%w orsen ed; w ith decom pressive lam inectom y 6 RT, 42%im proved w h ile 13%w orsen ed;
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w ith posterior decom pression w ith stabilizat ion, 64%im proved; an d n ally w ith an an terior approach , 75%im proved w ith 10% m ortalit y. Prevailing convict ion h olds th at if com pression is of sh ort du rat ion , n eurologic de cit s m ay be reversible, as re-m yelin at ion an d recover y of fu n ct ion are p ossible. How ever, w ith prolonged com pression , secon dar y vascu lar injur y w ith in farct ion of th e spin al cord m ay occu r w ith irreversible con sequ en ce. Based on th ese an d sim ilar st u dies, gen erally accepted in d icat ion s for surger y in clude: th e n eed for t issue for diagn osis; spinal in stabilit y; cord com pression w ith dysfun ct ion from bon e or t um or n ot radiosen sit ive; an d deteriorat ion or recurren ce during/despite RT. Surgical decom pression to preven t irreversible dam age sh ou ld be im m ediate. Conversely, RT is a reason able altern at ive for p at ien ts w ith radiosen sit ive t u m ors, st able neurologic st at us, n o spin al in stabilit y, n o sign i can t bony com prom ise of can al, or life expectan cy less th an 3 m on th s. The location of the origin of the tum or (isolated epidural disease versus arising from osseous lesion w ith extension) as well as considerations of spinal stabilit y should dictate choice of operative procedure. A thorough description of all surgical ap proaches is beyond the scope of this chapter. However, a sim ple lam inectom y should be reserved for dorsally located disease, and a posterolateral or ventral approach should be utilized w henever ventral disease is present, as tum ors m ay continue to grow or swell and thus w ithout a direct rem oval of the o ending pathology, an indirect decom pression w ill result in further deform ation of the spinal cord. At the spinal cord level (occiput to bottom of conus m edullaris), the cord should never be retracted to gain access to ventral tum or; the approach should be selected that obtains the m ost advantageous angle to access the tum or instead.
Preprocedure Consideration Radiographic Imaging Com pu ted tom ography (CT) m yelography w as on ce th e diagn ost ic tool of ch oice for evalu at ion of SEH. CT m yelogram also is m ore invasive an d carries th e risk of seeding in fect ion . It is th erefore n o longer recom m en ded in th e con text of spin al ep idu ral abscess. Magn et ic reson an ce im aging (MRI) w ith or w ith out CT h as em erged as th e less invasive an d m ore available m eth od of ch oice. MRI also o ers th e advan t age of di eren t iating bet w een t um or, in fect ion , h ern iated disk, an d h em atom a 20 (Figs. 17.1 an d 17.2). CT is also n ecessar y to evaluate for bony invasion an d st abilit y (Fig. 17.3).
Medication For SEH, in pat ien t s w h o cann ot tolerate surger y, an t icoagu lat ion sh ould be stopped an d possibly reversed; h igh dose steroids sh ould be con sidered alth ough th eir u se is con t roversial.21 For SEA, broad-sp ect rum IV an t ibiot ics sh ould be in it iated im m ediately, in cluding coverage for Gram -posit ive cocci an d Gram -n egat ive rods. For MESCC, steroids decrease edem a and m ay have an oncolytic e ect on som e t um ors such as lym phom a and breast cancer.
17
a
Spinal Epidural Com pression
b
Fig. 17.1a, b Spinal epidural hem atoma. (a) Axial and (b) sagit tal MRI in a patient with focal spontaneous hematoma around the central herniated disk located ventral to the cord.
Operative Management Anesthesia For all cases, gen eral en dot rach eal an esth esia is th e preferred tech nique, assum ing favorable an atom y an d th e pat ien t’s con dit ion . In t ubat ion -related m an ipulat ion of th e n eck con cern s in pat ien t s w ith cer vical spin al cord com pression n eed to be w eigh ed again st th e u rgen cy of obt ain ing a reliable air w ay. W h ere possible, a m in im ally m an ipulat ion tech n ique—su ch as
a
aw ake beropt ic, lar yngeal in t ubat ion w ith an illum in ated lar yngoscope w ith cam era, or n asal in t u bat ion in a pat ien t w ith n o risk factors for cribriform fract u re or in com p eten ce—sh ou ld be used. W h en em ergen t air w ay com prom ise is presen t an d in t ubat ion is n ot likely to be able to be perform ed in a t im ely fash ion , th en em ergen t cricothyroid or t rach eostom y in t u bat ion w ill n eed to be p erform ed , an d it w ou ld be pru den t to h ave a t rach eostom y kit at th e side of any pat ien t w ith em ergen t spin al cord com pression in case th ey deteriorate on th eir w ay to or from
b
Fig. 17.2a, b Spinal epidural abscess. (a) Axial T2-weighted MRI of the cervical spine in a patient who presented with acute rapidly progressive paraplegia and respiratory failure. There is a large dorsal epidural abscess collection with cord compression. (b) Sagit tal postcontrast image of a posterior thoracolumbar spine abscess associated with multiple areas of vertebral body osteomyelitis including T11, L2 through L5, and diskitis at L23.
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b
a
any procedu re, or even in th e op erat ing room d u ring stan dard en dot rach eal in t u bat ion . For those cases w here the opportunit y presents and the surgeon w ishes, if intraoperative m onitoring is to be used, then the anesthetic should take into account any potential e ects on electrom yography or m otor evoked potential (MEP) m onitoring by focusing on a total intravenous anesthetic (TIVA) technique to prevent the detrim ental im pact of inhalational anesthetic. TIVA also includes the absence or m inim al use of paralytics to prevent their im pact upon the m uscle activit y being m onitored by electrom yography (EMG) or MEP. Som atosensory evoke potentials (SSEPs) are used to avoid potential peripheral nerve com plications such as arm positioning apraxias, or even in ltration of an IV leading to com partm ent syndrom e, w hich if caught intraoperatively instead of identi ed postoperatively m ay result in im m ediate treatm ent of the problem and prevent perm anent m orbidit y. W here practical and feasible, m ean arterial pressures (MAP) sh ould be m ain tain ed as h igh as can be tolerated (u p to 100 m m Hg), an d w h en a n eu rologic de cit is presen t , if th e pat ien t can tolerate, MAPs in th e 901 m m Hg range sh ould be th e goal, to m ain tain spin al cord perfusion given th e presum ably edem atou s state of th e spin al cord. Th is can be correlated w ith in t raoperative evoked potent ial m onitoring, and m any tim es a decrem ent in evoked poten tials can be corrected w ith elevat ion of the MAP.
Surgical Approach General Principles Posit ion select ion d ep en ds on several factors, in clu ding th e locat ion of th e prim ar y path ology (an terior, posterior, or lateral w ith in th e can al), n um ber of levels, an d di cult y approach ing
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Fig. 17.3a, b Metastatic epidural spinal cord compression. (a) Sagit tal CT reconstruction and (b) axial CT image in a patient with known m etastatic breast cancer with sudden paraplegia and incontinence after a fall. A large destructive L1 vertebral body lesion is also invading both pedicles, left more than right, with signi cant ventrolateral cord compression. There is a resultant kyphotic deformit y at T12.
th e path ology directly, su ch as w h en a t rach eostom y, an terior scar, sp in al deform it y, or oth er con dit ion m akes th e app roach m ore ch allenging or h as h igh er risks of com p licat ion . W h ere possible, th e m ost direct approach leads to th e best resu lt ing t reat m en t , but on e or m ore factors m ay ch ange th at decision process, in cluding availabilit y of an access surgeon , result ing postoperat ive in stabilit y, an d pat ien t appropriaten ess for stabilizat ion tech n iques, am ong oth ers. W h en th e disease process or th e approach to th e disease causes spin al in st abilit y, fu sion of th e u n stable levels is addit ion ally recom m en ded. Several t reatm en t opt ion s exist (allograft bon e, p olym ethyl m eth acr ylate [PMMA] cem en t w ith Stein m an pin s, t it an ium cages, carbon ber cages, an terior t it an ium plate/rod xat ion devices, etc.), th e discussion of w h ich is beyon d th e scope of th is ch apter. A dedicated spin al t able can h elp to posit ion properly an d possibly preven t di eren t posit ion ing com plicat ion s, as w ell as being radiolu cen t to opt im ize im aging. Kn ee-elbow p osit ion on a stan dard n on spin al operat ing room t able can be used for dorsal th oracic or lum bar procedures. W h ile an on -call n eurom on itoring team m ay be desirable, on e sh ou ld n ot d elay th e case to w ait for a team to be available. For dorsal/dorsolateral path ology, a un ilateral approach is often su cien t . For sh ort-segm en t path ologies, such as focal abscess or lateral an d d orsal ep idu ral sp in al m etast ases, a m icrosurgical in t ralam in ar approach can be used as is don e for h ern iated disks. Ven t ral lu m bar path ology, located ven t rolaterally or below th e con u s m edu llaris, can be app roach ed in a sim ilar w ay w ith gen tle ret ract ion of th e th ecal sac. Soft (i.e., n ot calci ed, bon e, or h ard brou s lesion s) lesion s at th e cord level, su ch as in th e cer vical or th oracic sp in e, can be approach ed via several approach es, depen ding on th e surgeon’s com fort level an d th e facilit y’s resou rces (in clu ding th e exp erien ce of th e even ing or on -call st a ). On e app roach is via
17 u n ilateral h em ilam in ectom y w ith part ial t ran spedicular decom pression to gain access to th e ven t ral locu s of purulen ce, leaving th e posterior m idlin e an d con t ralateral st ru ct ures in t act to m in im ize delayed in st abilit y, reduce th e size of th e w oun d an d cavit y to be closed, an d redu ce in t raoperat ive bleeding. Th e less p ed icle rem oved, th e m ore st able th e sp in e w ill be over t im e. Should a m ore exten sive exposure n eed to be perform ed (com plete pedicle rem oval, bilateral decom pression plus t ran sp edicu lar, or rem oval of th e pars in terart icu laris), a fusion of th e poten t ially un stable segm en ts m ay be n ecessar y, an d w h ere app ropriate, in st ru m en tat ion sh ou ld be u sed. In st ru m en tat ion sh ou ld n ot be forgon e ju st becau se th e p rim ar y p ath ology is in fect ion . W h ere ap p rop riate, a bilateral p osterolateral m in im ally invasive approach from a part ial t ran sp edicu lar or costot ran sverse ap proach on eith er side can be p erform ed as w ell, w ith angled in st ru m en ts pu sh ing p ath ology dow n an d aw ay from th e cord. W h en th e path ology is liquid (acute abscess or relat ively lique ed h em atom a), an angled in ser t ion tech n ique can allow for placem en t of a sm all-caliber d rain (like a ven t ricu lostom y cath eter) th at can be used to rem ove ven t ral path ology an d facilit ate irrigat ion in th e abscess plan e. In gen eral, w e do n ot recom m en d a st raigh t lam in ectom y for p redom in ately ven t rally located in fect ion s at cord-level cases, u n less th ere is en ough room to reach th rough laterally located p u ru len t collect ion s an d p ass a righ t-angled in st ru m en t ven t ral to th e th eca in to th e ven t ral pus w ith out pressure on th e already ten u ou s sp in al cord . In acu te cases, th ere is rarely m u ch ep idu ral bleed ing, bu t in m ore ch ron ically in fected cases, th ere m ay be an in am m ator y rin d th at h as sign i can t vascu lar inp u t . Ep idu ral d rain s sh ou ld be left beh in d, an d drain age con t in ued longer th an st an dard durat ion to preven t any furth er collect ion or con t am in at ion of in fected m aterial in th e epid ural space.22 For m et ast at ic epidural disease, th e locat ion of th e origin of th e t u m or (isolated epidural disease versus arising from osseou s lesion w ith exten sion ) as w ell as con sid erat ion s of sp in al st abilit y sh ou ld dict ate ch oice of op erat ive p rocedu re.23 A th orough descript ion of all surgical approach es is beyon d th e scop e of th is ch apter. How ever, a sim p le lam in ectom y sh ou ld be reser ved for dorsally located disease, an d a posterolateral or ven t ral ap proach sh ou ld be u t ilized w h en ever ven t ral d isease is presen t , as t u m ors m ay con t in u e to grow or sw ell an d th u s w ith out a direct rem oval of th e o en ding path ology, an in direct decom p ression w ill resu lt in fu rth er deform at ion of th e sp in al cord. At th e spin al cord level (occip u t to bot tom of con u s m edu llaris), th e cord sh ou ld n ever be ret racted to gain access to ven t ral t u m or; th e ap proach sh ou ld be selected th at obtain s th e m ost advan t ageou s angle to access th e t u m or in stead.
Posterior Approaches Lam in ectom y alon e is to be u sed at th e spin al cord level on ly w h en th e disease is w h olly dorsal or ju st posterior to th e n er ve root if lateral. Any m ass ven t ral to th e n er ve root , u n less prim arily liqu id an d able to be drain ed w ith a cath eter p assed in an exist ing m ass ch an n el (e.g., an abscess th at w raps arou n d th e lateral aspect of th e dura), sh ould be resected or drain ed via a posterolateral ap p roach , an d th e m ore ven t ral an d m ed ial th e locat ion , th e m ore lateral th e approach sh ould be. Th e posterolateral approach es, in order of successively m ore lateral
Spinal Epidural Com pression
(an d th erefore m ore ven t ral access) locat ion , in clude: lam in ectom y, t ran spedicular, costot ran sversectom y (in th oracic spin e on ly), an d lateral ext racavitar y. Th e parascapular approach is a varian t of th e costot ran sversectom y or lateral ext racavit ar y at th e levels of T2–7 w h ere th e m uscles of th e scapu la n eed to be carefully separated an d th e scapula m obilized for th e exposu re, an d recon n ected carefu lly after w ard to p reven t m orbidit y.
Anterior Approaches Cervical • Tran soral, w h ich gives good access from th e clivus to C3 • St an dard ven t rom edial an terior cer vical, w h ich gives good access from C2 to T1 or T2
Cervicothoracic and Thoracic • Su p raclavicu lar, w h ich gives access at th e cer vicoth oracic
• • • •
•
ju n ct ion (dow n to T3) via an ap p roach th at is sim ilar to th e t radit ion al ven t rom edial an terior cer vical approach , but uses a m ore acu te angle to ap p roach th e th oracic vertebrae. Transsternal, w hich gives good access to the T3-T10 region, but there is an association w ith an increased risk of m ediastinit is. Tran sm an u brial, w h ich can be com bin ed w ith ven t rom edial to give access to C5-6 dow n to T2-3, alth ough th ere is a risk of injur y to m ajor vascular or chylou s st ruct ures. Tran sth oracic, w h ich gives excellen t ven t ral access to th e T4-T11 region s an d can be used to expose m ult iple levels, but in creased pulm on ar y m orbidit y lim it s it s u se today. Th oracoscopic approach es, w h ich give sim ilar access as th e t ran sth oracic w ith less pu lm on ar y m orbidit y, in clude a sign i can t learn ing cu r ve an d th e p or t size lim it s som e of th e access an d procedu res th at can be perform ed. Th oracoabdom in al, w h ich gives a w ide exposure to th e vertebral bodies an d ven t ral cord at th e region of T10 to L2, bu t requires split t ing of th e diap h ragm , an d h as a h eigh ten ed risk of injur y to abdom in al an d th oracic viscera.
Lumbar • Ret rop eriton eal or direct lateral exposu res from L1-S1. Varia-
•
t ion s of th ese can be used at di eren t levels, w ith good exposu re of th e vertebral bodies w ith less risk to in t rap eriton eal organ s, alth ough th e t ran spsoas tech n iques do h ave greater risks to th e n er ves, an d th e m ore ven t ral ap p roach es h ave a greater risk of inju r y to u reters an d great vessels. Tran speriton eal, w h ich gives good exposu re from L1/2 to th e u pper sacrum ; th is can give good exp osu re to th e bodies an d th ecal sac, but lim itat ion s in clude w orking arou n d th e aort a an d in ferior ven a cava (IVC); risk to bow el, bladder, or u reter; an d in m ales a risk of sexu al dysfu n ct ion d u e to ret rograde ejacu lat ion , believed by som e to be related to injur y to th e sym path et ic p lexu s.
The follow ing illustrations dem onstrate som e of the m ore com m on em ergency procedures for epidural com pression. W hile open approaches are dem onstrated here, m inim ally invasive ap proaches can be chosen depending on the surgeon’s judgm ent and experience as n oted in th e case exam ples. Som e of the oth er approaches m en tion ed are addressed in detail in oth er ch apters.
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Operative Procedure Positioning for Posterior and Posterolateral Procedures Positioning and Incision (Fig. 17.4a, b)
a
b
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Figure
Procedural Steps
Fig. 17.4
(a) The patient is placed prone on a spinal table and/or Wilson frame (b) w ith an incision marked as diagrammed.
17
Spinal Epidural Com pression
Thoracic Laminectomy for Dorsal Spinal Epidural Hematoma Laminectomy (Fig. 17.5)
Figure
Procedural Steps
Fig. 17.5
After incising the fascia and dissecting the muscle o of the spinous processes and laminae, the laminae are removed w ith a drill/ Leksell rongeur exposing the epidural hematoma. It is important to remove as much of the laminae at consecutive levels until the superior and inferior limits of the hematoma have been reached.
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Hematoma Removal (Fig. 17.6)
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Figure
Procedural Steps
Fig. 17.6
A Woodson or Pen eld dissector is used in conjunction w ith suction to removed congealed hematoma taking care not to put undue pressure on the thecal sac and spinal cord. Irrigation is helpful in assisting hematoma removal.
17
Spinal Epidural Com pression
Lumbar Laminectomy for Epidural Abscess Laminectomy (Fig. 17.7)
Figure
Procedural Steps
Fig. 17.7
After incising the fascia and dissecting the muscle o of the spinous processes and laminae, the laminae are removed w ith a drill/ Leksell rongeur and Kerrison rongeurs.
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Nerve Root Retraction and Abscess Removal (Fig. 17.8a, b)
Figure
Procedural Steps
Pearls
Fig. 17.8
For ventral and ventrolateral disease related to a diskitis or mycobacterium infection, the nerve root is retracted gently w ith a Pen eld no. 4.
• It is important to send m ultiple
(a) In the case of liquid purulent material, the abscess is evacuated w ith suction and a small catheter can be placed to ush out material from the epidural space ventrally and under adjacent laminae. (b) For chronic infections consisting of granulation tissue or granuloma, abnormal material is removed w ith small pituitary rongeurs, Woodson and Pen eld dissectors, along w ith suction.
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cultures for bacterial (anaerobic and aerobic), fungal, and acid fast bacilli in addition to pathology.
17
Spinal Epidural Com pression
Transpedicular Approach for Metastatic Disease Laminectomy (Fig. 17.9)
Figure
Procedural Steps
Fig. 17.9
After incising the fascia and dissecting the muscle o of the spinous processes and laminae, the laminae are removed w ith a drill/ Leksell rongeur exposing the epidural tumor. It is important to remove as much of the laminae at consecutive levels until the superior and inferior limits of the epidural mass have been reached.
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Pediculectomy (Fig. 17.10)
Figure
Procedural Steps
Pearls
Fig. 17.10
If not already disrupted by tumor a bur is used to perform a partial facetectomy at the location of the pedicle and neural foramen. The pedicle is drilled dow n to the level of the posterior vertebral body. A Kerrison rongeur can be used to remove more of the facet to expose the neural foramen if tumor is occupying this area.
• Many tum ors arising from the vertebrae have eroded the
•
298
pedicles. If there is lateral and ventral tum or without pedicle erosion, it will be necessary to drill the pedicle down to the posterior aspect of the vertebral body to rem ove tum or without retracting the thecal sac and spinal cord. Unilateral pediculectomy in the thoracic spine does not necessarily require stabilization, while bilateral pediculectom ies do. A costotransversectomy can be perform ed if substantial vertebral body erosion has occurred and instrum entation in planned to improve anterior colum n support (see Chapter 15).
17
Spinal Epidural Com pression
Lateral and Ventral Tumor Removal (Fig. 17.11)
Figure
Procedural Steps
Fig. 17.11
Without retracting the thecal sac and spinal cord, lateral and ventral tumor is removed w ith Pen eld and Woodson dissectors. Dow n-going spinal curettes can be used to push ventral tumor aw ay from the thecal sac. The tumor is collected by suction and small pituitary rongeurs.
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Special Considerations
Closing • Th e w oun ds are irrigated copiou sly w ith n orm al salin e. • All e p id u ral ble e d in g sh ou ld b e coagu lat e d an d h e m ost at ic 8
m at e r ial ca n b e left , as lon g as t h e h e m ost at ic su bst a n ce is n ot left in a w ay t h at w ill cau se im m e d iat e or d elaye d (d u e to sw ellin g of t h e m at e r ial ove r t im e ) sp in a l cord com p ression . • A su ct ion drain age device m ay be left in th e su bfacial p lan e in th e postoperat ive period. • Th e m uscle an d facial layers are closed w ith n o. 0 absorbable su t u re. Th e facia is closed t igh tly w ith n o gap s. Th e subcut an eous layer is closed w ith 2–0 or 3–0 absorbable sut u re an d th e skin is closed w ith st aples.
Postoperative Management Monitoring • Close n eu rologic m on itoring sh ou ld be p erform ed in all cases •
•
after su rger y. SEH: if a coagu lop athy w ere presen t p reop erat ively, it sh ou ld be follow ed w ith h em atology laboratories an d t reated to n orm al valu es for at least 1 to 2 days after w ard su rger y. Treatm en t beyon d th at rarely h as ben e t , as th e p at ien t w ill revert to th eir n orm al state even t u ally. SEA: W h ile single valu es of er yth rocyte sedim en t at ion rate (ESR)/C-react ive protein (CRP) are m in im ally in form at ive, serial ESR an d CRP levels can be t ren ded to re ect th e cou rse of in fect ion .
Medication • SEA: An t ibiot ics are con t in u ed u p to 12 w eeks p ostoperat ively,
•
th ough th e usu al cou rse is 4–6 w eeks. Th erapy sh ould be in it iated w ith IV an t ibiot ics, an d can be t ran sit ion ed to oral an t ibiot ics at a later t im e. As cu lt ures yield a causat ive agen t , coverage can be n arrow ed accordingly. MESCC: Ch em oth erapy is lim ited except for a few ch em osen sit ive en t it ies su ch as Ew ing sarcom a an d n eu roblastom a. Dep en d ing on th e exten t of decom p ression , steroids m ay be con t in ued or t apered.
Radiographic Imaging • MESCC: Recu r ren ce sh ou ld be w atch ed for via p osit ron em ission tom ograp hy (PET)/CT, MRI, or CT scan . Progressive sp in al d eform it y m ay suggest eith er t u m or recu r ren ce or p rogression , or develop m en t of late rad iat ion -in du ced osteon ecrosis.
Adjuvant Treatments • MESCC: Radiat ion th erapy is u su ally an app rop riate adju n ct to t reat m en t postoperat ively after rem oval of epidural t um ors.
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Spinal Epidural Hematoma Sp in al an esth esia is u sed for su rgeries of th e low er ext rem it ies, su ch as h ip ar th roplast y an d am pu t at ion s, an d in obstetrics. Risk of an SEH is 1:150,000 to 1:190,000 in th is con text . Th e prim ar y predisposing factors are t rau m at ic in ser t ion an d/ or rem oval of th e cath eter an d coagulopathy. How ever, given th e h igh risk of deep vein th rom bosis (DVT) in both h ip arth roplast y an d low er ext rem it y am pu t at ion s, cu rren t recom m en dat ion s en dorse in it iat ion of th erap eu t ic an t icoagu lat ion 2 h ours after th e spin al n eedle is in ser ted or epidural cath eter is rem oved. An t icoagu lat ion sh ou ld be fu r th er delayed if th ere is a h em orrh age.2 Postop erat ive SEH su rfaces as a p ar t icu larly p er t in en t topic in th e set t ing of postoperat ive DVT/pulm on ar y em bolism prophyla xis. Postoperat ive SEH sh ou ld be su spected in any pat ien t w ho develops n ew n eu rologic de cit s after surger y. In ciden ce across m any st u dies is 1% or less. Preop erat ive coagu lop athy is th e m ost im por tan t risk factor. Oth er risk factors in clude age greater th an 60; u se of n on steroidal an t i-in am m ator y drugs (NSAIDs); Rh 1 blood group; greater th an 5-level procedure; h em oglobin level less th an 10; blood loss greater th an 1 L; an d in tern at ion al n orm alized rat io (INR) greater th an 2.0 in th e rst 48 h ou rs. Curren tly th ere is in su cien t eviden ce to o er precise recom m en dat ion s of w h en to st ar t postoperat ive ch em oprophylaxis for DVTs.3 Traum at ic SEH h as been associated w ith spin al fract ures. In one series, approxim ately h alf of pat ien t s w ith a t raum at ic spin al fract u re also su ered from an SEH. In th is series, t reat m en t focu sed exclu sively on th e fract u re. Th e ou tcom e in p at ien ts w ith n eurologic de cits w ere equivalen t in both th e group w ith a t rau m at ic SEH an d th e grou p w ith ou t .24
Spinal Epidural Abscess Th e un derlying con dit ion th at predisposed the pat ien t to developing a sp in al abscess sh ou ld be invest igated, if n ot im m ediately kn ow n . W h ile perfectly h ealthy pat ien t s can develop a spin al abscess w ith ou t oth er risk factors, th is is ext rem ely rare an d a search for a p redisposing factor sh ou ld be u n der taken at th e sam e t im e as th e t reat m en t itself. An t ibiot ics sh ould be con t in ued for several w eeks after drain age, if un der t aken , an d th e du rat ion w ill depen d on th e in fect ious agen t an d local sen sit ivit ies. Th e in am m at ion su rrou n ding th e sp in al cord from th e in fect ion can cause local th rom bosis an d isch em ia, an d th e associated hyp oten sion th at can n orm ally d evelop from any spin al cord inju r y or sh ock m ay w orsen th is e ect . If th e pat ien t h as any sign s of hyp oten sion , at least acu tely, th is sh ou ld be m an aged, p ossibly in an in ten sive care environ m en t , u n t il th e pat ien t is st abilized or at least for th e rst 48 h ours or so.
MESCC Em erging technologies becom ing increasingly relevant, especially for those w ho cannot tolerate surgery, include stereotactic radiosurgery, proton beam , radiofrequency ablation, and cryotherapy.
17 Minim ally invasive surgical treatm ents m ay lower the bar for surgical intervention, especially if it facilitates reoperation or reim aging w ith less artifact If postoperative radiation is anticipated, incision placem ent m ay be m odi ed in a m anner that w ill m inim ize exposure to the eld of radiation and m axim ize potential for wound healing.
References 1. Reih sau s E, Wald bau r H, Seeling W. Spin al ep idu ral abscess: a m et a-an alysis of 915 pat ien t s. Neurosurg Rev 2000;23(4): 175–204, discussion 205 2. Al-Mu t air A, Bedn ar DA. Spin al epid u ral h em atom a. J Am Acad Or th op Su rg 2010;18(8):494–502 3. Glot zbecker MP, Bon o CM, Wood KB, Harris MB. Postoperat ive spin al ep idu ral h em atom a: a system at ic review. Sp in e 2010; 35(10):E413–E420 4. Tom p kin s M, Pan u n cialm an I, Lu cas P, Palu m bo M. Sp in al Ep idu ral Abscess. Jou r Em er Med . 2010;39(3):384–390 5. Felden zer JA, McKeever PE, Sch aberg DR, Cam p bell JA, Ho JT. The p ath ogen esis of spin al epidural abscess: m icroangiograph ic st udies in an experim en t al m odel. J Neurosurg 1988;69(1): 110–114 6. Patch ell RA, Tibbs PA, Regin e W F, et al. Direct decom pressive surgical resect ion in th e t reat m ent of spin al cord com pression caused by m et ast at ic can cer: a ran dom ised t rial. Lan cet 2005;366(9486):643–648 7. Rad es D, Heiden reich F, Karsten s JH. Fin al resu lt s of a p rospect ive st udy of th e progn ost ic value of th e t im e to develop m otor de cit s before irrad iat ion in m et ast at ic sp in al cord com p ression . In t J Radiat On col Biol Phys 2002;53(4):975–979 8. Krep p el D, An ton iadis G, Seeling W. Sp in al h em atom a: a literat ure sur vey w ith m et a-an alysis of 613 pat ien t s. Neurosu rg Rev 2003;26(1):1–49 9. Joh n son KG. Sp in al ep idu ral abscess. Crit Care Nu rs Clin Nor th Am 2013;25(3):389–397 10. Heusn er AP. Non t uberculous spinal epidural infect ion s. N Engl J Med 1948;239(23):845–854 11. Yang SY. Spin al ep idu ral abscess. N Z Med J 1982;95(707): 302–304
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12. Rigam on t i D, Liem L, Sam path P, et al. Spin al epidural abscess: con tem porar y t ren ds in et iology, evaluat ion , an d m an agem en t . Surg Neurol 1999;52(2):189–196, discussion 197 13. Byrn e TN, Borges LF, Loe er JS. Met ast at ic epidural spin al cord com pression : update on m an agem en t . Sem in On col 2006; 33(3):307–311 Review 14. Cole JS, Patch ell RA. Met ast at ic epidural spinal cord com pression . Lan cet Neu rol 2008;7(5):459–466 15. Gilbert RW, Kim JH, Posn er JB. Epidural spin al cord com pression from m et ast at ic t u m or: diagn osis an d t reat m en t . An n Neu rol 1978;3(1):40–51 16. Rodriguez M, Din apoli RP. Spinal cord com pression : w ith special referen ce to m et ast at ic epidural t um ors. Mayo Clin Proc 1980;55(7):442–448 17. Fessler RG, Steck JC, Giovan in i MA. Anterior cer vical corpectom y for cer vical spondylot ic m yelopathy. Neurosurger y 1998;43(2):257–265, discussion 265–267 18. Loblaw DA, Perr y J, Ch am bers A, Laperriere NJ. System at ic review of th e diagn osis an d m an agem en t of m align an t ext radu ral spin al cord com pression : th e Can cer Care On t ario Pract ice Guidelines In it iat ive’s Neuro- On cology Disease Site Group. J Clin On col 2005;23(9):2028–2037 Review 19. With am TF, Kh avkin YA, Gallia GL, Wolin sky JP, Gokaslan ZL. Surger y in sigh t: cu rren t m an agem en t of ep idu ral sp in al cord com pression from m et ast at ic spin e disease. Nat Clin Pract Neurol 2006;2(2):87–94, quiz 116 20. Braun P, Kazm i K, Nogués-Melén dez P, Mas-Estellés F, ApariciRobles F. MRI n dings in spin al subdural an d epidural h em atom as. Eur J Radiol 2007;64(1):119–125 21. Sh ort DJ. El Masr y WS, Jon es PW. High dose m ethylpredn isolon e in th e m an agem en t of acute spin al cord injur y—a system at ic review from a clin ical perspect ive. Midlan ds Cen t re for Spin al Inju ries, Rober t Jon es & Agn es Hu n t Or th op aedic & Dist rict Hospit al NHS Tr ust , Osw est r y, Sh ropsh ire, SY109DP, UK. 22. Recinas P, Pradilla G, Crom pton P, Th ai Q, Rigam ont i D. Spin al Epidural Abscess: Diagn osis an d Treat m en t . Operat ive Tech n iques in Neurosu rger y 2004;7:188–192 23. Quraish i NA, Gokaslan ZL, Borian i S. Th e surgical m an agem en t of m et ast at ic epidural com pression of th e spin al cord. J Bon e Join t Surg Br 2010;92(8):1054–1060 24. Benn et t DL, George MJ, Oh ash i K, El-Khour y GY, Lucas JJ, Peterson MC. Acu te t rau m at ic sp in al ep idu ral h em atom a: im aging an d n eurologic outcom e. Em erg Radiol 2005;11(3):136–144
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Treatment of Acute Cauda Equina Syndrome Harel Deut sch
Introduction Acu te cau da equ in a syn drom e is th e su dden com p ression of th e n er ves in th e lu m bar cistern resu lt ing in p ain an d n eu rologic im p airm en t . Th e spin al cord en d s at approxim ately th e L1 to L2 levels an d, th erefore, cau da equin a com pression involves th e n er ve roots rath er th e spin al cord. Clin ically it m ay n ot be p ossible to di eren t iate bet w een a con u s m edu llaris inju r y versu s a cau da equ in a syn drom e. Neu rologic m an ifestat ion s in clu de bilateral leg w eakn ess, loss of sen sat ion , an d bladder an d bow el p roblem s. True cau da equ in a syn drom e is rare because th e n er ve root s are m ore resist an t to com p ression th an th e spin al cord. Acute cau da equin a syn drom e th erefore requires severe com pression an d a rapid on set of com pression . Causes in clude an acu te lu m bar disk h ern iat ion or a lu m bar fract u re/dislocat ion . Ch ron ic com pression is an ext rem ely rare cau se of cauda equ in a sym ptom s. Treat m en t involves gen erally a w ide lu m bar lam in ectom y an d rem oval of th e com p ression . In cases w h ere th ere is a fract u re or dislocat ion , spin al redu ct ion an d in st ru m en tat ion m ay be n ecessar y. Oth er cau ses of cau da equ in a syn drom e in clu de h em atom as, t u m ors, an d in fect ion s su ch as ep idu ral abscesses.
Indications • Pat ien t s w ith acu te cau da equ in a syn drom e h ave leg w eak-
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•
302
n ess, decreased low er ext rem it y sen sat ion , an d bladd er reten t ion . Im aging st udies sh ow severe lum bar acute com p ression . Pat ien t s also gen erally h ave severe low er back an d bilateral leg pain. Som e lu m bar sten osis is a com m on n ding on m agn et ic reson an ce im aging (MRI) scan s. Cau da equin a syn drom e is n ot p ossible u n less th e sten osis is ver y severe. Add it ion ally, m ost pat ien t s w ith ver y severe lu m bar sten osis do n ot h ave cauda equin a syn drom e. For a cau da equin a syn drom e to occur th ere usu ally is an acute w orsen ing of th e baselin e sten osis. Som et im es a sm all acu te disk m ay be su p erim p osed on ch ron ic severe sten osis. Pat ien t s w ith acu te cau da equ in a syn drom e h ave u rin ar y reten t ion . Bladder cath eterizat ion after th e pat ien t t ries to void
•
• •
allow s docu m en t at ion of th e post void residu al. A p ost void residual over 100 m L suggests a n eurogen ic bladder. Bow el function is not usually apparently disturbed in acute cauda equina syndrom e. Patients m ay have severe constipation and im pacted stool. Diarrhea or “loss of bowel” issues are not com m on ndings in acute cauda equina syndrom e. For pat ien ts w ith a t raum at ic lu m bar fract u re as th e cau se of an acu te cau da equ in a syn drom e, su rger y m ay be requ ired to address n eu rologic issu es as w ell as sp in al colu m n stabilit y. Th is ch apter depicts decom pression for an acu tely h erniated lum bar disk causing sign i can t sp in al can al com p rom ise.
Preprocedure Considerations Radiographic Imaging • MRI is th e p referred im aging st u dy to evalu ate for severe
•
•
lum bar com pression . T2-w eigh ted MRI is excellen t in sh ow ing th e absen ce h igh in ten sit y cerebrospin al uid sign al at th e level of th e com pression (Fig. 18.1). If MRI in u n available or pat ien t factors p reclu d e get t ing an MRI, th en a com p u ted tom ograp hy (CT) m yelogram m ay dem on st rate severe sten osis or a com plete block to con t rast ow at th e level of com p ression . For pat ien ts w ith t raum at ic lu m bar fract ures, X-rays an d CT scan s are essen t ial to evalu ate align m en t an d fract u res.
Medication • An t ibiot ics are adm in istered prior to in cision . • Updated guidelines released in 2013 recom m end against the use of steroids in spinal cord injur y. The guidelines conclude, “In su m m ar y, th ere is n o con sisten t or com pelling m edical evidence of any class to just ify the adm inistration of MP [m ethylprednisolone 1,2 ] for acu te SCI [spin al cord injur y]. Both consistent and com pelling Class I, II, and III m edical evidence exists suggest ing th at high -dose MP adm in ist rat ion is associated w ith a variet y of com plicat ions including infection , respirator y com prom ise, GI hem orrhage, and death. MP sh ould not be routinely used in the t reatm ent of patients w ith acute SCI.”3
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Treatm ent of Acute Cauda Equina Sym drom e
Foley Catheter Placement
Operative Field Preparation
• Pat ien t s m ay h ave sign i can t u rin ar y reten t ion leading to hy-
• Alcoh ol prep is perform ed before povidon e iodine or chlorh ex-
p oten sion because of blad der disten sion .
•
idin e application . Th e in cision s are m arked an d in lt rated w ith 1% lidocain e w ith epin eph rin e 1:100,000.
Fig. 18.1 Lumbar T2-weighted MRI sagit tal and axial images with severe stenosis at L5-S1.
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Operative Procedure Positioning (Fig. 18.2)
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Figure
Procedural Steps
Pearls
Fig. 18.2
Patient positioning. The patient is positioned prone. X-ray or uoroscopy is used to localize the level and plan the incision.
• There are several options for beds. Bolsters can be used for the chest. A Wilson fram e allows for opening up of the lum bar spine. A spinal table with hip and chest pads avoids abdom inal compression and m ay reduce bleeding due to venous congestion. In patients undergoing a fusion, a Wilson fram e should be used carefully to avoid an iatrogenic at back syndrom e.
18
Treatm ent of Acute Cauda Equina Sym drom e
Skin Incision (Fig. 18.3)
Figure
Procedural Steps
Fig. 18.3
(a) The incision is made w ith a no. 10 blade and extends about 5 cm. (b) A monopolar is used to extend the incision through the posterior lumbar fascia.
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Subperiosteal Dissection (Fig. 18.4)
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Figure
Procedural Steps
Pearls
Fig. 18.4
The monopolar is used to strip the paraspinal muscles from the spinous process and lamina. The medial facet joint is exposed.
• Staying in the subperiosteal space helps reduce bleeding. Constant bleeding from the m uscle m ay interfere with subsequent steps. Preserving the facet capsule rather may prevent future facet arthropathy. Fluoroscopy or X-ray im aging is used to con rm the level.
18
Treatm ent of Acute Cauda Equina Sym drom e
Lumbar Laminectomy (Fig. 18.5)
Figure
Procedural Steps
Pearls
Fig. 18.5
The spinous process is removed and the lamina is removed using a high-speed drill, Kerrison, and/or Leksell rongeurs. A high-speed drill is helpful for performing a partial medial facetectomy.
• The pars articularis is preserved to m aintain lum bar stabilit y.
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Lumbar Diskectomy (Fig. 18.6a, b)
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Figure
Procedural Steps
Pearls
Fig. 18.6
(a) The dura is retracted and if there is a signif cant disk herniation component, the disk fragment is removed. The disk space is often incised and disk material removed w ith pituitary rongeurs under magnif cation. (b) The nerve root and thecal sac are inspected for any remaining fragments or compression.
• With a large ventral disk herniation, dural retraction m ay be very di cult or impossible initially. More bone m ay need to be rem oved laterally. As the decompression progresses, dural retraction is easier.
18
Closing Lumbar Incision • Th e w oun d is h eavily irrigated. • A m edium suct ion drain age device is placed deep an d brough t • • •
out th rough a separate skin in cision . Th e posterior lum bar fascia is reapproxim ated using 0 ab sorbable su t u re in an in terru pted fash ion . In terru pted loose m u scle su t u res to obliterate dead sp ace are opt ion al. Th e subcut an eous t issue is closed using several in terrupted 2-0 Vicr yl sut ures. The skin is closed w ith staples or a m ono lam ent nylon sut ure.
Postoperative Management Medication • Tw o to th ree doses of prophylact ic an t ibiot ics in th e im m ediate postoperat ive period are opt ion al. Longer term an t ibiot ics or an t ibiot ics for drain m an agem en t are discouraged.
Further Management • Drain s are rem oved w h en drain age is m in im al (less th an •
50 m L per sh ift). Skin su t u res or st aples are rem oved after 2 w eeks.
Special Considerations Timing of Surgery The tim ing of surgery and in uence on outcom e in cases of cauda equina surgery is the subject of m ultiple investigations.4 The literat ure indicates outcom e is m ore related to preoperative con dition th an th e speci c tim ing of inter vention . Studies sh ow people w ith com plete urinary incontinence have a poor outcom e an d patients w ith a w eak stream or decreased sensation having a bet ter outcom e. Sh apiro et al reported an im provem ent for patients operated on w ithin 48 hours 5 after review ing 14 patients w ith cauda equina syndrom e. All patients had bilateral sciatica an d leg w eakness. Of the 14 patien ts, 13 had urinar y in contin ence, 9 m assive disk h erniations, and 5 sm all disk herniations superim posed on stenosis. All patients were am bulatory. Sh apiro foun d 7/10 patients w ith no in continence had surgery w ith in 48 hours. The four patients w ith incontinence after surger y all h ad surgery after 48 hours. Shapiro et al concluded surgery w ithin 48 hours is w arranted in cauda equina patients. Tator et al u sed a sur vey to determ in e curren t pract ices in t im ing of surger y for spin al cord injur y. Of th e 585 cases th ey su r veyed, 5.6%w ere cau da equ in a cases.6 In gen eral 23.5%of pat ien ts h ad su rger y w ith in 24 h ours of injur y. In an other st udy, Tator et al fou n d n o im provem en t w ith acute surger y for spin al cord injur y.7 Th e coh or t of 208 pat ien t s in clu ded som e pat ien t s w ith cauda equ in a injur y. In a review of th e literat ure, Feh lings et al con clu ded an im al st u dies sh ow bet ter ou tcom e w ith early
Treatm ent of Acute Cauda Equina Sym drom e
decom pression for spin al cord injur y.8 Th e literat u re review ed w as m ain ly sp in al cord inju r y dat a rath er th an cau da equ in a in ju ries. Feh lings et al con clu d ed th at early decom p ression w ith in 24 h ou rs is recom m en ded for spin al cord injuries.9 Gleave et al, Qu resh i et al, an d Olivero et al sh ow ed su rgical t im ing did n ot a ect pat ien t ou tcom e in cau da equ in a syn drom e.10–12 Rath er, outcom e w as depen den t on th e pat ien t’s preoperat ive n eurologic stat us. Cases of cau da equ in a syn drom e sh ould be t reated expedit iou sly.13 W h ile absolu te t im ing m ay n ot m ake a d i eren ce, earlier su rgical in ter ven t ion s seem s to p reven t fu r th er deteriorat ion . Cau da equ in a syn drom e inju ries sh ou ld be dist ingu ish able from inju ries to th e con u s m ed u llaris. Th e con u s m edu llaris is th e term in al port ion of th e spin al cord an d represen t s a cen t ral n er vou s system st ru ct u re. Ou tcom es m ay be di eren t w ith con u s inju ries.
References 1. Bracken MB, Sh ep ard MJ, Holford TR, et al. Adm in ist rat ion of m ethylpredn isolon e for 24 or 48 h ours or t irilazad m esylate for 48 h ou rs in th e t reat m en t of acute spin al cord injur y: result s of th e th ird n at ion al acu te sp in al cord inju r y ran dom ized con t rolled t rial. JAMA 1997;277:1597–1604 2. Bracken MB, Shepard MJ, Holford TR, et al. Methylprednisolone or tirilazad m esylate adm inistration after acute spinal cord injury: 1-year follow up. Results of the third National Acute Spinal Cord Injury random ized controlled trial. J Neurosurg 1998;89(5):699–706 3. Hurlbert RJ, Hadley MN, Walters BC, et al. Pharm acological therapy for acute spinal cord injury. Neurosurgery 2013;72(Suppl 2):93–105 4. Kingw ell SP, Cu r t A, Dvorak MF. Factors a ect ing n eu rological outcom e in t raum at ic con us m edullaris an d cauda equin a inju ries. Neurosurg Focus 2008;25:E7 5. Sh apiro S. Cau da equ in a syn drom e secon dar y to lu m bar d isc h ern iat ion . Neurosu rger y 1993;32(5):743–747 6. Tator CH, Feh ling M, Th orp e K, Math M, Taylor W. Cu rren t u se an d t im ing of spin al surger y for m an agem en t of acute spin al cord injur y in Nor th Am erica: result s of a ret rospect ive m ult icen ter st udy. J Neurosurg 1999;91(1):12–18 7. Tator CH, Du n can eG, Edm on ds VE. Com p arison of su rgical an d con ser vat ive m an agem en t in 208 pat ien t s w ith acu te spin al cord inju r y. Can J Neurol Sci 1987;14:60–69 8. Feh lings M, Perrin RG. Th e t im ing of su rgical in ter ven t ion in th e t reat m ent of spin al cord injur y: a system at ic review of recen t clin ical eviden ce. Spin e 2006;31:S32–S35 9. Feh lings MG, Vaccaro A, Wilson JR, et al. Early versu s d elayed d ecom pression for t raum at ic cer vical spinal cord injur y: result s of th e su rgical t im ing in acu te spin al cord inju r y st u dy (STASCIS). PLoS On e 2012;7:e32037 10. Gleave JRW, Macfarlan e R. Cauda equin a syn drom e: w h at is th e relat ion sh ip bet w een t im ing of su rger y an d ou tcom e? Br J Neurosurg 2002;16:325–328 11. Olivero W, Wang H, Han igan W, et al. Cauda equin a syndrom e (CES) from lu m bar disc h ern iat ion s. J Spin al Disord Tech 2009;22(3):202–206 12. Quresh i A, Sell P. Cauda equin a syndrom e t reated by surgical decom pression : th e in u ence of t im ing on surgical outcom e. Eur Spin e J 2007;6(12):2143–2151 13. DeLong W B, Polissar N, Neradilek B. Tim ing of su rger y in cauda equin a syn drom e w ith urinar y retent ion : m et a-an alysis of obser vat ion al st udies. J Neurosurg Spine 2008;8(4):305–320
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Removal of Spontaneous Intracerebral Hemorrhages Just in Mascitelli, Yakov Gologorsk y, and Joshua Bederson
Introduction
Preprocedure Considerations
Sp on t an eou s in t racerebral h em orrh age (ICH) accou n t s for 10– 30% of all st rokes an d is a sign i can t cause of m orbidit y an d m ort alit y arou n d th e w orld. Alth ough it is th e secon d m ost com m on form of st roke after isch em ic in farct , spon tan eous ICH is th e m ost deadly t yp e of st roke w ith a 30-day m ort alit y as h igh as 50%. Un like isch em ic in farct s, spon t an eou s ICH u su ally p rogresses over m in utes to h ou rs often w ith w orsen ing h ead ach e, n au sea, vom it ing, alterat ion s of con sciou s, an d deteriorating n eu rologic stat u s. Th e m ost com m on locat ion for a spon t an eou s ICH is deep (in clu ding th e basal ganglia, th alam u s, an d in tern al capsu le) follow ed by lobar, cerebellar, an d brainstem . Rapid diagn osis an d m an agem en t is cru cial as early deteriorat ion is com m on w ith in th e rst few h ours after on set .1,2
Radiographic Imaging • Com puted tom ography (CT) can be obtained rapidly and clearly
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•
Indications Supratentorial ICH
•
dem onstrates high density blood w ithin brain parenchym a. In addition, the ellipsoid m ethod (diam eter of the clot in each dim ension: anteroposterior [AP], lateral [LAT], and height [HT]) can be used to calculate ICH volum e and has prognostic signi cance.6 ◦ Ellip soid volu m e 2 AP 3 LAT 3 HT / 2 Magn et ic reson an ce im aging (MRI) is n ot th e in it ial diagn ost ic im aging m odalit y of ch oice du e to th e t im e n eeded to com plete the st udy as w ell as th e com plicated appearan ce of acu te blood on MRI.7 CT angiograp hy (CTA) is recom m en ded for all pat ien t s except th ose older th an 45 years of age w ith preexist ing hyp erten sion an d ICH in th e th alam u s, pu tam en , or cerebellum (Fig. 19.1).8 CTA h as low er yield for cerebellar ICH in com p arison to su p raten torial ICH. Preoperat ive im aging (Fig. 19.2).
• Precise in dicat ion s for su rger y are con t roversial1–4 an d sh ou ld
• •
be based on th e in dividual pat ien t’s n eu rologic condit ion , th e size an d locat ion of th e h em atom a, th e p at ien t’s age, an d th e fam ily’s w ish es. The 2010 Am erican Stroke Association/Am erican Heart Association (ASA/AHA) guidelines recom m end standard craniotom y for lobar clots greater than 30 m L and w ithin 1 cm of surface. In gen eral, factors th at favor su rgical m an agem en t 5 in clu de: ◦ Lesion s w ith m arked m ass e ect , edem a, or m idlin e sh ift; ◦ Lesion s w ith sym ptom s th at ap pear to be secon dar y to in creased in t racran ial pressure (ICP) or m ass e ect; ◦ Moderate clot volu m e; ◦ Persisten tly elevated ICP desp ite m axim al m edical m an agem en t; ◦ Rapid n eu rologic deteriorat ion ; ◦ Favorable locat ion s: lobar, cerebellar, extern al cap su le, n on dom in an t h em isp h ere; ◦ You ng age; ◦ On set of sym ptom s less th an 24 h ou rs old.
Infratentorial ICH • 2010 ASA/AHA in dicat ion s for surgical evacuat ion of cerebellar ICH1 ◦ Pat ien t s w h o are deteriorat ing n eu rologically ◦ Brain stem com p ression ◦ Hydrocep h alu s from ven t ricu lar obst ru ct ion
312
Fig. 19.1 CTA demonstrating right cerebellar arteriovenous malformation with associated intracranial hemorrhage and intraventricular hemorrhage (IVH).
19
Rem oval of Spontaneous Int racerebral Hem orrhages
• •
•
•
Fig. 19.2 Case example: frontal craniotomy. CT head demonstrating large right frontal intracranial hem orrhage with mild mass e ect and midline shift and no hydrocephalus.
Initial Management and Medication 1,2
•
•
• In it ial m on itoring sh ou ld t ake place in an in ten sive care u n it •
•
or oth er m on itored set t ing. Blood pressu re sh ou ld be p rom ptly bu t n ot over-aggressively con t rolled. In pat ien ts presen t ing w ith systolic blood pressure (SBP) of 160–220 m m Hg, th e auth ors prefer n icardipin e in fu sion w ith a goal SBP of 140–160 m m Hg. For p at ien ts w ith clin ical seizu res or elect roen ceph alography (EEG) eviden ce of seizure act ivit y, th e auth ors prefer ph enytoin . Alth ough seizure prophylaxis is debated in th e set t ing of ICH, th e au th ors also p refer ph enytoin for th e preven t ion of
early seizu res in p at ien t s w ith lobar ICH. Glucose sh ould be m on itored an d n orm oglycem ia m ain t ain ed . Platelet t ran sfu sion an d factor rep lacem en t sh ou ld be given to all pat ien t s w ith severe th rom bocytopen ia or coagulat ion factor de cien cy, respect ively. For p at ien t s w ith a coagulopathy, con siderat ion sh ould be given to giving p rot am in e su lfate, vitam in K, fresh frozen p lasm a, cr yop recip it ate, or oth er clot t ing factors. For pat ien ts w ith a h istor y of an t iplatelet m edicat ion use, th e auth ors prefer desm op ressin acetate alon e for th ose u n dergoing con ser vat ive m an agem en t an d desm opressin plus platelet t ran sfu sion for th ose u ndergoing surgical m an agem en t . Curren tly recom bin an t factor VIIa (rFVIIa) is n ot recom m en ded given it s th rom boem bolic risk.9 Regarding th e preven t ion of deep ven ous th rom bosis an d p ulm on ar y em bolism , all pat ien ts sh ould h ave in term it ten t p n eum at ic com pression , an d ph arm acological prophylaxis sh ou ld be con sidered on ce cessat ion of bleeding h as been docum en ted. Treat m en t of elevated ICP sh ould begin w ith sim ple m easu res su ch as h ead of bed elevat ion , an algesia, an d sedat ion . More aggressive m easu res to reduce ICP in clu de osm ot ic diu resis, cerebrospin al uid (CSF) drain age, paralysis, hyper ven t ilat ion , hypoth erm ia, an d barbit urate com a. Pat ien t s w ith obst ru ct ive hyd rocep h alu s sh ou ld u n dergo em ergen t placem en t of an extern al ven t ricu lar drain (EVD) in th e in ten sive care un it prior to surger y. Altern at ively, an EVD m ay be placed in th e op erat ing room at th e t im e of su rger y as long as th is is don e expedit iously. In th e au th ors’ exp erien ce, u pw ard cerebellar h ern iat ion d u e to EVD over-drain age is ext rem ely rare. Non eth eless, EVD drain age sh ould be lim ited by set t ing a gradien t n o less th an 10 cm H2 O p rior to su rger y.
Operative Field Preparation • Th e exposed skin is sterilized w ith povidon e iodin e or •
ch lorh exidin e applicat ion . Th e in cision is m arked an d in lt rated w ith 1% lidocain e w ith ep in ep h rin e 1:100,000.
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Operative Procedure Frontal Craniotomy10 Positioning and Skin Incision (Fig. 19.3)
Figure
Procedural Steps
Pearls
Fig. 19.3
The patient is placed supine on the operating table.
• A frontal craniotomy is described here. Of
The May eld skull clamp is placed w ith the single pin at the equator in contralateral frontal bone above the orbit and the paired pins placed at the equator in the ipsilateral occipital lobe.
•
Alternatively, the patient’s head may be placed on a horseshoe or a donut w ithout a May eld clamp.
• The head is rotated as far as possible to the contralateral side w ithout obstructing the airw ay or venous drainage.
• The super cial temporal artery (STA) should be palpated at the level of the zygoma and the vertical limb of the incision should be placed betw een the artery and the tragus.
•
The incision begins at the zygoma and then curves posteriorly to the parietal eminence and upw ard from the auricle to reach 2 cm from the midline.
• The incision is then carried forw ard to the frontal region and curved across the midline just behind the hairline.
314
course, the exact craniotomy should always be tailored to the location of the ICH. Su cient tim e should be devoted for ICH localization before the incision is m arked. The patient’s head position should be correlated with the CT scan. It is often helpful to draw the planned craniotomy on the scalp. If tim e perm its, a volum etric CT scan m ay be obtained and intraoperative navigation m ay be used for precise localization of the ICH. When applying the May eld clamp, the frontal sinus and m astoid air cells should be avoided. Care should be taken to avoid the frontal branch of facial nerve that originates just below the root of the zygom a and travels in the super cial temporal facia to the orbital rim .11 Care should also be taken when dissecting adjacent to the auricle to not violate the external auditory canal.
19
Rem oval of Spontaneous Int racerebral Hem orrhages
Subcutaneous Dissection (Fig. 19.4)
Figure
Procedural Steps
Pearls
Fig. 19.4
The skull is then exposed by incising the temporalis muscle posteriorly and superiorly and elevating the muscle anteriorly and inferiorly w ith a periosteal elevator.
• Use of electrocautery to elevate the temporalis m uscle m ay result in injury to the trigem inal nerve m otor bers. Mechanical elevation with a periosteal elevator is preferred.
The approach of Spetzler and Lee 12 involves leaving a cu of temporalis superiorly that can be used during the closure.
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Craniotomy (Fig. 19.5)
Figure
Procedural Steps
Pearls
Fig. 19.5
The craniotomy should be started w ith a single bur hole, the location of w hich is tailored to the planned craniotomy (in this case, it is placed at the posterior superior temporal line).
• It is helpful to again re-correlate with the •
The craniotomy is then w idened using the craniotome. A high speed drill can be used to atten the orbital roof and remove the inner table of the frontal bone if needed.
316
•
CT scan prior to m aking the craniotomy. While drilling the inner table of the frontal bone, care should be taken not to enter the orbit or frontal sinus. If this were to occur, the orbit can be packed with oxidized cellulose and the sinus with m uscle/fascia. If the temporal air cells are entered, they should be thoroughly waxed.
19
Rem oval of Spontaneous Int racerebral Hem orrhages
Dural Opening (Fig. 19.6)
Figure
Procedural Steps
Pearls
Fig. 19.6
Before opening the dura, tack up sutures should be placed along the entire craniotomy to prevent postoperative epidural hematoma formation.
• Placem ent of dural tack ups m ay be delayed until after ICH evacuation if the patient is actively herniating and im m ediate ICH evacuation is necessary.
There are many fashions in w hich the dura may be opened. The authors prefer a C-shaped opening w ith the dura re ected anterior/inferiorly in the same direction as the scalp/muscle.
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Hematoma Evacuation (1) 13 (Fig. 19.7a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 19.7
(a) A corticotomy is then performed w here the hematoma comes closest to the surface (a).
• Eloquent tissue should be avoided when choosing the •
Bipolar cautery should be used along the planned cortical incision to prevent bleeding. The cortical incision is then made using a no. 11 blade.
318
location for the corticotomy. Intraoperative ultrasound m ay be used if the ICH does not com e to the cortical surface. (b) Intraoperative ultrasound im age of a large frontal basal ganglia hem atom a (arrow).
19
Rem oval of Spontaneous Int racerebral Hem orrhages
Hematoma Evacuation (2) (Fig. 19.8)
Figure
Procedural Steps
Pearls
Fig. 19.8
A malleable can be used to gently retract the cortical opening.
• Self-retaining retractors are not advised as they
The hematoma is then evacuated from w ithin the cavity. The center of the hematoma is evacuated rst follow ed by the peripheral blood.
• •
Bipolar cautery is used to stop bleeding from the cavity w alls. Gelatin sponge and oxidized cellulose available in various forms may also be used for nal hemostasis.
can dam age norm al parenchym a. The operating m icroscope m ay be used for this part of the case for increased illum ination and m agni cation, if needed. Special at tention should be paid for sm all tum ors, cryptic arteriovenous m alform ations (AVMs), and cavernous angiom as.
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Closing
• Th e w oun d is copiously irrigated. • A m ediu m su ct ion drain age device is placed in th e subgaleal
• On ce adequ ate h em ost asis h as been ach ieved, th e du ra is
•
closed using run n ing or in terrupted 4-0 braided nylon sut ures (th e dura m ay be left open if in creased ICP is a poten t ial con cern ). Th e bon e ap is placed an d secured w ith plates an d screw s (th e bon e plate m ay be m arsupialized in th e abdom en if in creased ICP is a poten t ial con cern ).
• • •
plan e. Th e tem poralis m uscle is reapproxim ated w ith 2-0 braided absorbable su t u res. Th e galea is approxim ated w ith 3-0 braided absorbable su t ure in an inverted, in terrupted fash ion . Th e skin is closed w ith 3-0 nylon sut ure in a run n ing fash ion or st aples.
Midline Suboccipital Craniectomy10 (Fig. 19.9a, b)
a
b Fig. 19.9a, b Case example: midline suboccipital craniectomy. (a) Large cerebellar intracranial hemorrhage causing e acement of the fourth ventricle and brainstem compression. (b) Hydrocephalus secondary to fourth ventricular compression.
320
19
Rem oval of Spontaneous Int racerebral Hem orrhages
Positioning (Fig. 19.10)
Figure
Procedural Steps
Pearls
Fig. 19.10
The head is xed in a May eld skull clamp w ith the single pin on the linea temporalis anterior to one external auditory meatus (EAM) and the paired pins on the opposite linea temporalis (one pin over the EAM and one pin anterior to the EAM).
• The m idline suboccipital craniectomy is described
The patient is placed in the prone position on the operating table on bolsters.
•
•
here. The lateral suboccipital craniectomy can also be used for m ore lateral cerebellar ICHs. Care should be taken to not hyper ex the neck and com prom ise the airway as well as to inspect and pad all pressure points. If not done already, an EVD should be placed rst. Once it has been secured, the patient should be turned to the prone position for the craniectomy.
The head should be in exion w ith as much distraction as possible.
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Skin Incision and Subcutaneous Dissection (Fig. 19.11)
322
Figure
Procedural Steps
Pearls
Fig. 19.11
A linear midline skin incision is made from the inion to the upper cervical vertebrae.
• The inferior extent of the incision should
The subcutaneous musculature is divided along the midline raphe. The muscle is re ected laterally.
•
be determ ined by the size of the planned craniectomy and need for C1 or C2 lam inectomy. The m idline raphe is avascular and blood loss can be m inim ized by remaining along that plane.
19
Rem oval of Spontaneous Int racerebral Hem orrhages
Craniectomy (Fig. 19.12a, b)
a
Figure
Procedural Steps
Pearls
Fig. 19.12
The craniectomy is made from just below the inion/torcula and carried dow nw ard tow ard the foramen magnum.
• The location and size of the lesion will
There are a number of w ays to perform the craniectomy; (a) the authors prefer to thin the bone w ith a high speed drill and then (b) complete the bone removal w ith rongeurs and punches.
determ ine the extent of the craniectomy; occasionally the posterior arch of C1 will need to be rem oved.
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b
324
19
Rem oval of Spontaneous Int racerebral Hem orrhages
Dural Opening and Hematoma Evacuation (Fig. 19.13)
Figure
Procedural Steps
Fig. 19.13
There are a number of w ays to perform the dural opening ; the authors prefer a Y-shaped opening w ith the superior dural ap re ected over the transverse sinus.
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Hematoma Evacuation (Fig. 19.14)
326
Figure
Procedural Steps
Pearls
Fig. 19.14
A cerebellar hematoma should be evacuated using the same techniques as a supratentorial hematoma.
• If the cerebellum is noted to be signi cantly swollen or irritated, consideration should be given to resection of a portion of the cerebellar hem isphere.
19
Rem oval of Spontaneous Int racerebral Hem orrhages ◦ Con sider keep ing p at ien t in t u bated for 24 to 48 h ou rs as
Closing • On ce adequ ate h em ostasis h as been ach ieved, th e d u ra is
• • • •
• •
closed using ru n ning or in terrupted 4-0 braided nylon sut ures (Valsalva m an euver sh ou ld be used to assure a w atert igh t dural closure). If th e cerebellu m is sw ollen , con sid erat ion sh ou ld be given to a du ral p atch graft . Th e w oun d is h eavily irrigated. A m edium suct ion drain age device is placed in th e epidural/ su bfacial p lan e. Th e m uscle an d fascia sh ould be approxim ated in layers using 2-0 braided absorbable su t ure (again , a w ater t igh t fascial closure sh ould be obt ain ed to preven t CSF leakage th rough th e w oun d). Th e derm is is approxim ated w ith 3-0 braided absorbable su t ure in an inver ted, in terrupted fash ion . Th e skin is closed w ith 3-0 nylon su t ure in a run n ing fash ion or staples.
Postoperative Management
5
• Pat ien t s sh ou ld be m on itored in an in ten sive care u n it . • Com plete postoperat ive labs sh ou ld be obt ain ed an d th e pa• • •
t ien t sh ould be kept NPO (n oth ing by m outh ). A CT scan of th e h ead sh ould be obtain ed to evaluate th e decom pression an d ven t ricular size (Figs. 19.15 an d 19.16). It is opt ion al to give t w o to th ree doses of p rophylact ic an t ibiot ics in th e im m ediate p ostop erat ive p eriod. Sp eci cally for cerebellar ICH ◦ Du ring th e p ostop erat ive evalu at ion , ch eck for respirator y rate an d p at ter, hyp er ten sion , an d evid en ce of CSF leak.
• •
a p recau t ion ar y m easu re as resp irator y arrest can occu r su dden ly. ◦ Hyp erten sion sh ou ld be avoided. ◦ Postop erat ive edem a or h em atom a are com p licat ion s th at can be seen in th e im m ediate postoperat ive period an d be rap idly fat al. ◦ St an dard EVD m an agem en t sh ou ld be u sed an d is n ot described in detail h ere. Drain s sh ou ld be rem oved on p ostoperat ive day 1 or 2. Su t u res or stap les sh ou ld be rem oved 1 to 2 w eeks after su rger y dep en d ing on su rgeon p referen ce.
Special Considerations Other Surgical Considerations In addit ion to stan dard cran iotom y, m ore m in im ally invasive tech n iques h ave been con sidered in cluding en doscopic aspirat ion an d stereot act ic in fu sion of th rom bolyt ics in to th e clot cavit y. En doscopic asp irat ion via a single bu r h ole h as been sh ow n to im prove ou tcom e.14 Alth ough in fu sion of th rom bolyt ics h as been sh ow n to reduce clot bu rden an d risk of death , rebleeding is a greater con cern an d fun ct ion al outcom e is n ot n ecessarily im proved.15 Both m inim ally invasive techn iques are st ill un der invest igat ion. Curren tly th ere is too lit tle dat a to com m en t on th e role of decom pressive h em icran iectom y as a t reat m en t opt ion for spon tan eous ICH alth ough it h as been sh ow n to be ben e cial for deep ICH in an im al m odels.16 Su rgical t im ing rem ain s con t roversial as w ell as th e de n it ion of “early su rger y.” Cu rren tly th ere is n o clear eviden ce th at th ere is a ben e t from eith er u lt ra early or delayed evacu at ion . In fact , u lt ra early cran iotom y h as been associated w ith recu rren t bleeding.1
Arteriovenous MalformationAssociated ICH
Fig. 19.15 Postoperative CT following evacuation of right frontal hematoma shown in Fig. 19.2.
Sp on t an eou s ICH can be secon dar y to AVM, an eu r ysm , or ven ou s angiom a ru pt u re. AVM h em orrh age p rod u ces ICH in 82% of cases an d less com m on ly in t raven t ricular h em orrh age (IVH), subarach n oid h em orrh age (SAH), or subdural h em orrh age (SDH). AVM resect ion is gen erally an elect ive p rocedu re. Many recom m en d, if p ossible, delaying AVM su rger y w eeks to m on th s after h em orrh age th u s allow ing th e p at ien t to st abilize an d th e clot to liqu efy.17–19 It h as been suggested th at if an AVM associated ICH is m an aged op erat ively, th e h em atom a sh ou ld be addressed rst as w ell as aggressive m an agem en t of in t raop erat ive ICP20 an d th at th e AVM sh ou ld on ly be addressed at th e sam e t im e if it is su per cial w ith easily elu cidated an atom y.21 As a caut ion , if AVM bleeding occurs, h em ostasis in th ese cases can be ext rem ely di cult . Gen tle an d prolonged t am pon ade is often ver y h elp ful an d h em ost at ic adjun ct s su ch as gelat in sp onge or p ow der are im p ort an t tools. Occasion ally persisten t bleeding an d can be m it igated w ith in d u ced hypotension . Cerebral perfusion pressure (CPP) sh ould alw ays be kept in m in d, h ow ever, esp ecially in p at ien t s w ith elevated ICP.
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a
b Fig. 19.16a, b (a) Postoperative CT following evacuation of cerebellar hematoma shown in Fig. 19.9. (b) Hydrocephalus has also improved (without an EVD in this particular case).
Rarely, AVM re-ru pt u re du ring ICH rem oval leads to bleeding th at can n ot be con t rolled w ith th e above m en t ion ed m an eu vers. In th ese desp erate circu m stan ces, u rgen t resect ion of th e AVM m ay be th e on ly life-saving m easure available to th e surgeon . If AVM resect ion is u n dert aken at th e t im e of h em orrh age, th e basic ten et s of AVM surger y sh ould st ill be m ain tain ed: w ide exposure, occlusion of large feeding arteries rst , circum feren t ial dissect ion of th e AVM n idu s, system at ic separat ion of th e AVM from w h ite m at ter, an d preser vat ion of drain ing vein s u n t il th e en d of th e procedure.19 W h en ever blood loss is sign i can t en ough to requ ire m ajor in fu sion of u ids an d t ran sfu sion of p acked red blood cells, con siderat ion sh ou ld be given to rep len ish ing fresh frozen p lasm a, platelet s, an d oth er clot t ing factors to avoid a dilu t ion al coagulop athy.
Aneurysmal ICH An eu r ysm ru pt u re t yp ically resu lt s in SAH bu t can also p rod u ce ICH an d u su ally involves an eu r ysm s distal to th e circle of Willis su ch as th e m id dle cerebral ar ter y (MCA) or an eu r ysm s th at h ave becom e adh eren t to th e brain . Pat ien t s w ith an eur ysm al ICH in gen eral h ave p oorer ou tcom es du e to m ass e ect an d in creased ICP.22 Un like th e t reat m en t for AVM associated ICH, ult ra early h em atom a evacu at ion an d an eu r ysm clipp ing in p at ien t s w ith poor clin ical grade h as been advocated for an eur ysm al ICH.23 Th ere is a m u ch greater im p or tan ce in secu ring th e an eu r ysm given th e prop en sit y for an d devastat ing con sequ en ces of an eur ysm re-rupt ure. Alth ough cath eter angiography is th e gold stan dard for an eu r ysm diagn osis an d p reop erat ive evalu at ion , som e advocate operat ing based on CTA alon e as th e delay could lead to w orse outcom e.24 If t im e p erm it s, h ow ever, con siderat ion sh ou ld be given to p reop erat ive angiography an d coil em bolizat ion to p rotect th e an eu r ysm from re-ru pt u re an d , in
328
t urn , allow for a m uch safer ICH evacuat ion .25 If preoperat ive em bolizat ion is n ot an opt ion du e to t im e con strain t s, th e su rgeon sh ou ld be fu lly p repared to clip th e an eu r ysm . Prior to en tering or evacu at ing th e ICH, th e operat ing room an d p erson n el sh ou ld be p rep ared for poten t ial an eu r ysm ru p t ure. Ideally, a discussion of the follow ing steps sh ould occur before th e skin in cision is even m ade. Th e operat ing m icroscop e sh ou ld be d raped an d ready. A fu ll select ion of tem p orar y an d perm an en t clip s sh ou ld be open on th e surgical eld. Th e an esth esiologist sh ou ld be p rep ared to adju st blood p ressu re rapidly. At least t w o (possibly th ree) large suction s sh ou ld be prepared an d ready. On ce th e h em atom a is en tered, a con ser vat ive evacuat ion is w arran ted. Part icular care sh ou ld be t aken n ear th e bot tom of th e ICH (n ear th e an eu r ysm ) to avoid u n du e m an ipu lat ion . If ru pt u re occu rs, su ct ion an d p recise tam p on ade are perform ed w h ile p roxim al arterial con t rol is obt ain ed. Th e an eu r ysm an atom y is de n ed su rgically an d th e an eu r ysm n eck is recon st ructed. After clipping an d ICH evacuation , th e pat ient sh ou ld h ave im m ediate angiograp hy, ideally in th e operat ing room . Fin ally, a th ird reason able opt ion in clu des cran iectom y w ith out ICH evacuat ion to im m ediately address ICP follow ed by im m ediate coil em bolizat ion .
External Ventricular Drainage Placem en t of an EVD sh ou ld be con sidered in all pat ien ts w ith IVH especially th ose w ith blood in th e th ird ven t ricle, th e cerebral aqueduct , or fourth vent ricle. Generally, th e EVD should be placed in th e lateral vent ricle cont ralateral to th e hem orrhage to avoid clogging th e cath eter. Alth ough in traven tricular t issue plasm in ogen act ivator (rt-PA) m ay h elp lyse clot and m aintain cath eter patency,26 it is still con sidered invest igat ion al an d sh ould not be used if th ere is a suspected vascular lesion . Im portan tly,
19 ven t ricu lar drain age alon e is n ot an acceptable treatm en t for cerebellar h em orrhage w ith associated hydroceph alus. Th ese patien ts should undergo surgical decom pression.1
References 1. Morgen stern LB, Hem p h ill JC 3rd, An d erson C, et al. Gu id elin es for th e m an agem ent of spon t an eous int racerebral h em orrh age: a guidelin e for h ealth care profession als from th e Am erican Hear t Associat ion /Am erican St roke Associat ion . St roke 2010; 41(9):2108–2129 2. Broderick J, Connolly S, Feldm ann E, et al; Am erican Heart Association/Am erican Stroke Association Stroke Council; Am erican Heart Association/Am erican Stroke Association High Blood Pressure Research Council; Qualit y of Care and Outcom es in Research Interdisciplinary Working Group. Guidelines for the m anagem ent of spontaneous intracerebral hem orrhage in adults: 2007 update: a guideline from the Am erican Heart Association/Am erican Stroke Association Stroke Council, High Blood Pressure Research Council, and the Qualit y of Care and Outcom es in Research Interdisciplinary Working Group. Circulation 2007;116(16):e391–413 3. Men delow AD, Gregson BA, Fern an d es HM, et al. Early su rger y versu s in it ial con ser vat ive t reat m en t in p at ien t s w ith sp on t an eous su praten torial in t racerebral h aem atom as in th e In tern at ion al Surgical Trial in In t racerebral Haem orrh age (STICH): a ran dom ised t rial. Lan cet 2005;365(9457):387–397 4. Teern st ra OP, Evers SM, Kessels AH. Met a an alyses in t reat m en t of spont an eous supraten torial in t racerebral h aem atom a. Act a Neuroch ir (Wien ) 2006;148(5):521–528 5. Green berg, Mark S. Han dbook of Neurosurger y. New York: Th iem e; 2010 6. Broderick JP, Brot t TG, Du ldn er JE, Tom sick T, Hu ster G. Volu m e of in t racerebral h em orrh age. A pow erful an d easy-to-use predictor of 30-day m or t alit y. St roke 1993;24(7):987–993 7. Bradley WG Jr. MR ap p earan ce of h em orrh age in th e brain . Radiology 1993;189(1):15–26 8. Zh u XL, Ch an MS, Poon WS. Sp on t an eou s in t racran ial h em orrh age: w hich pat ien t s n eed diagn ost ic cerebral angiography? A prospect ive st udy of 206 cases and review of th e literat u re. St roke 1997;28(7):1406–1409 9. Diringer MN, Skoln ick BE, Mayer SA, et al. Th rom boem bolic even t s w ith recom bin an t act ivated factor VII in Spon t an eous In t racerebral h em orrh age: result s from the factor seven for acute h em orrh agic st roke (FAST) t rial. St roke 2010;41:48–53 10. Clat terbuck RE, Tam argo RJ. Surgical posit ion ing and exposures for cran ial procedures. In : Win n HR, ed. Youm ans Neurological Surger y. 5th ed. Ph iladelphia: Saun ders; 2004 11. Yasargil MG, Reich m an MV, Ku bik S. Preser vat ion of th e fron totem poral bran ch of th e facial n er ve using th e in terfacial tem poralis ap for pterion al craniotom y. Tech n ical ar t icle. J Neurosurg 1987;67:463–466
Rem oval of Spontaneous Int racerebral Hem orrhages 12. Spet zler RF, Lee KS. Recon st ru ct ion of th e tem poralis m uscle for th e pterion al cran iotom y: Tech n ical n ote. J Neu rosurg 1990;73:636–637 13. Singh RV, Pru sm ack CJ, Morcos JJ. Spon t an eous in t racerebral h em orrh age: non -ar terioven ous m alform at ion , n on an eu r ysm . In : Win n HR, ed. You m an s Neurological Surger y. 5th ed. Ph iladelp h ia: Sau n d ers; 2004 14. Auer LM, Dein sberger W, Niederkorn K, et al. En doscopic surger y versus m edical t reat m en t for spon t an eous in t racerebral h em atom a: a ran dom ized st udy. J Neurosurg 1989;70(4):530–535 15. Teern st ra OP, Evers SM, Lodder J, Le ers P, Fran ke CL, Blaauw G. Mu lt icen ter ran dom ized con t rolled t rial (SICHPA). Stereot act ic t reat m ent of in t racerebral h em atom a by m ean s of a plasm in ogen act ivator: a m ult icen ter random ized con t rolled t rial (SICHPA). St roke 2003;34(4):968–974 16. Marin kovic I, St rbian D, Pedron o E, et al. Decom pressive cran iectom y for in t racerebral hem orrh age. Neurosu rger y 2009 Oct;65(4):780–786 17. Mart in NA, Wilson CB. Preoperat ive an d postop erat ive care: Man agem en t of in t racran ial h em orrh age. In : Wilson CB, Stein BM, eds. In t racran ial Ar terioven ous Malform at ion s. Balt im ore: William s & Wilkin s; 1984: 121–129 18. Solom on RA, Stein BM. Managem en t of deep supraten torial an d brain stem arterioven ous m alform at ions. In : Barrow DL, ed. In t racran ial Vascular Malform at ion s. Park Ridge, IL: Am erican Associat ion of Neurological Surgeon s; 1990: 125–141 19. Yasargil MG. Micron eurosurger y. Vol 3B. AVM of th e Brain : Clinical Con siderat ion s, Gen eral an d Special Operat ive Tech n iques, Surgical Result s, Non operat ive Cases, Cavern ous an d Ven ous An giom as, Neuroan esth esia. New York: Th iem e; 1987 20. Jafar JJ, Rezai AR. Acute surgical m an agem ent of in t racran ial arterioven ou s m alform at ion s. Neurosurger y 1994;34(1):8–12 21. St arke RM, Kom ot ar RJ, Hw ang BY, et al. Treat m en t guidelin es for cerebral ar terioven ou s m alform at ion m icrosurger y. Br J Neurosurg 2009;23(4):376–386 22. Hau erberg J, Eskesen V, Rosen orn J. Th e progn ost ic signi can ce of in t racerebral h aem atom a as sh ow n on CT scann ing after an eur ysm al subarach n oid h em orrh age. Br J Neurosurg 1994;8(3):333–339 23. Gueresir E, Beck J, Vat ter H, et al. Subarach n oid h em orrh age an d in t racerebral h em atom a: in cidence, progn ost ic factors, an d outcom e. Neurosurger y 2008;63(6):1088–1093 24. de los Reyes K, Patel A, Bederson JB, Fron tera JA. Man agem en t of subarach n oid h em orrh age w ith in t racerebral h em atom a: clip ping an d clot evacuat ion versus coil em bolizat ion follow ed by clot evacuat ion . J Neuroin ter v Surg 2013;5(2):99–103 25. Bergdal O, Springborg J, Hauerberg J, Eskesen V, Poulsgaard L, Rom n er B. Outcom e after em ergen cy surger y w ith out angiography in pat ien t s w ith in t racerebral h aem orrhage after an eur ysm r u pt u re. Act a Neu roch ir (Wien ) 2009;151(8):911–915 26. Engelh ard HH, An drew s CO, Slavin KV, Ch arbel FT. Curren t m an agem en t of in t raven t ricular h em orrh age. Surg Neurol 2003 Ju l;60(1):15–21
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Surgery for Acute Intracranial Infection P. B. Rak sin
Introduction Sp ace-occu pying in t racran ial in fect ion m ay arise via con t iguous spread from adjacen t st ruct ures, th rough h em atogen ous dissem in at ion , follow ing operat ive n eurosurgical procedures, or after h ead t raum a. Th e sam e st ruct ural elem en ts th at den e th e variou s in t racran ial com p ar t m en ts—ep id u ral, su bdu ral, p aren chym al, an d ven t ricu lar—also dictate th e p ath w ays for sp read of in fect ion across th ose n at u ral barriers. Man agem en t t yp ically involves a com bin at ion of m edical an d su rgical m odalit ies.
Epidural Abscess In fect ion w ith in th e space bet w een th e in n er t able of th e calvariu m an d d u ra occu rs m ost com m on ly as a com plicat ion of p aran asal sin u sit is, orbit al cellu lit is, m astoidit is, or ch ronic ot it is m edia. It m ay also occu r follow ing t rau m at ic fract u re of th e calvarium or follow ing cran iotom y. Rarely, epidural abscess m ay follow from fetal scalp m on itoring or th e ap p licat ion of h alo p in s to th e sku ll.1 Clin ical p resen t at ion is often in sidiou s. Headach e m ay be accom pan ied by a relat ive p au cit y of oth er sym ptom s u n less m ass e ect is p resen t or th e in fect iou s p rocess exten ds to th e subdu ral space as w ell. Periorbit al edem a occurs in conjun ct ion w ith bon e osteom yelit is or orbital cellulit is. (Pot t’s pu y t um or is th e h istorical term applied to th e clin ical n ding of foreh ead soft t issue sw elling du e to th e presen ce of subgaleal uid.2 ) An in fect ious n idus adjacen t to th e pet rous ap ex m ay p resen t as Graden igo syn drom e. St reptococci (St reptococcus m illeri grou p) p redom in ate, th ough p ost t rau m at ic an d p ostcran iotom y in fect ion s are m ore com m on ly associated w ith st ap hylococci.3
Subdural Empyema In fect ion w ith in th e p oten t ial sp ace bet w een du ra an d arach n oid m ater arises eith er from th e sp read of in fect ion via valveless em issar y vein s (in associat ion w ith th rom bop h lebit is) or via exten sion of an osteom yelit is of th e sku ll w ith an accom panying epidural abscess. Oth er predisposing con dit ion s in clude sku ll t rau m a, in fect ion of a p reexist ing su bd u ral h em atom a, or prior n eurosurgical procedu re. A sm all n um ber are m et ast at ic (often from a p u lm on ar y sou rce). Su bd u ral em pyem a m ay also occu r in u p to 10% of in fan t s w ith bacterial m en ingit is, presum ably as th e result of in fect ion of a previously sterile
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su bdu ral e u sion .4 Fever is p resen t in m ost cases. Headach e an d vom it ing are t yp ical early n dings. Th ese sym ptom s m ay be accom pan ied by con fusion , seizure, an d focal n eurologic deficit s (m ost com m only h em iparesis). Neurologic declin e m ay be rap id follow ing sym ptom on set . On th e oth er h an d, p ost su rgical su bdural em pyem a m ay presen t in a delayed fash ion —up to 8 w eeks follow ing in it ial in ter ven t ion .3 A less fulm inan t course m ay be seen w ith p rior an t im icrobial th erapy, as w ell as in th e set t ing of m et ast at ic sp read to th e su bdu ral sp ace or in fect ion of an exist ing subdu ral h em atom a. Bacterial isolates are sim ilar to th ose fou n d in epidu ral abscess cases. Polym icrobial in fect ion is com m on . Th e in ciden ce of cult ure-n egat ive (27–29% in on e series) cases is greater in subdural em pyem a 5 ; th is m ay reect th e fast id iou s n at u re of m any an aerobic organ ism s.
Intracerebral Abscess Focal, en capsulated in fect ion w ith in th e brain t issu e m ay be single or m u lt ifocal. A single abscess t yp ically arises by d irect exten sion of a paran asal sin u s, m astoid, or m iddle ear in fect ion ; a solitar y focu s m ay also arise follow ing p en et rat ing t rau m a. Mu lt ifocal d isease m ore com m on ly resu lt s from h em atogen ou s dissem in at ion of prim ar y cardiac, pulm on ar y, periodon t al, ab dom in al, or derm atologic in fect ion . Less th an 50% of pat ien t s w ill presen t w ith th e classic t riad of h eadach e, fever, an d focal n eu rologic de cit .6 In fact , pat ien t s m ay p resen t w ith h eadach e or n ausea alon e. Fever, w h en presen t , is t ypically low -grade; a tem perat ure of greater th an 101.5° F (38.6° C) sh ou ld raise su sp icion for a system ic in fect ion . Focal n eu rologic sym ptom s re ect th e locat ion of th e path ology. Hem iparesis is com m on .7 New on set of m en ingism u s, associated w ith su dd en n eu rologic w orsen ing, m ay in dicate ru pt u re in to th e ven t ricu lar sp ace. Mort alit y in su ch cases is h igh .8 Isolated p ath ogen s are p redom in an tly bacterial, com m on ly polym icrobial, an d re ect th e site of origin . St reptococci are isolated in u p to 70% of cases. Bacteroides an d Prevotella are presen t in 20–40% of cases an d often occur in m ixed cult ure. Staphylococcus aureus is p resen t in 10–15% of brain abscesses—usually p ost t raum a or in th e set t ing of en docardit is—an d is u su ally m on om icrobial. En teric Gram -n egat ive bacilli are presen t in up to 22–33% of cases, often in associat ion w ith ot ic foci, bacterem ia, or prior n eurosu rgical p rocedu re.9 Diagn ost ic con siderat ion s m u st be exp an ded in cases of im m unocom prom ise. Gram -n egat ive organ ism s an d fu ngal isolates are com m on in cases of n eu t rop h il de cien cy, w h ile Listeria, Nocardia, Cryptococcus, an d Toxoplasm a are en coun tered in th e set t ing of T-cell de cien cy.
20
Indications Th e in dicat ion s for surgical in ter ven t ion are dict ated by size, an atom ic locat ion , an d accessibilit y, as w ell as by kn ow n or p resu m ed p ath ogen . In all cases, su rgical in ter ven t ion m ust be cou pled w ith appropriate in t raven ou s (an d, in cert ain cases, in t rath ecal) an t im icrobial th erapy.
Epidural Abscess Most cases requ ire op en n eu rosu rgical debrid em en t . Bu r h ole drain age gen erally is in e ect ive given th e ten acit y of th e pu ru len t m aterial; h ow ever, in select cases w h ere a ver y sm all collect ion is presen t , t rial bur h ole drain age m ay be at tem pted. Th e par t icipat ion of Otolar yngology m ay be n ecessar y for sim u ltan eou s debridem en t of th e a ected sin u s(es).
Surgery for Acute Intracranial Infection
coexisten t hydroceph alus w h ere sh un t placem en t risks con t am in at ion, or w h ere m edical con t rain dicat ion s to invasive in ter ven t ion m ay exist .13 In a p at ien t w ith docu m en ted bacterem ia an d a posit ive cult ure, con siderat ion m ay be given to a t rial of system ic an t im icrobial th erapy, provided th e ch osen agen t(s) o ers good cent ral n er vous system pen et rat ion . If th e diagn osis is in quest ion an d/or th ere is a quest ion of a polym icrobial in fect ion in an im m u n ocom p rom ised h ost , con sid erat ion sh ou ld be given to early biopsy to perm it t ailoring of m edical th erapy.
Preprocedure Considerations Radiographic Imaging • CT h ead p re- an d p ost-con t rast w ill provid e basic in form a-
Subdural Empyema Th e vast m ajorit y of cases requ ire open n eurosurgical debridem en t . More lim ited bu r h ole drain age m ay be con sidered in cases of p arafalcin e em pyem a, crit ically ill p at ien ts in sept ic sh ock, an d ch ildren p resen t ing w ith em pyem a secon dar y to m en ingit is.10 Repeated drain age an d/or conversion to cran iotom y m ay be n ecessar y in such cases.
•
Intracerebral Abscess Several factors dictate th e in dication s for an d exten t of n eu rosurgical in ter ven tion . Prim ar y con siderat ion s in clu de th e m at urit y of th e capsule, size, an d location . Brit t an d En zm an n sough t to de n e stages in th e m at u ration of th e abscess capsule.11 Cort ical in am m ation—or, cerebritis—alone is not a surgical disease. Dem arcation of an abscess cavit y w ith respect to th e surroun ding parenchym a begins abou t 10 days after the onset of infection. The capsule w all, how ever, rem ain s thin and discontinuous at this t im e. Abscesses m ay be am enable to cannulation and drain age—w ithout at tem pted resection of the w all—during this early en capsulat ion ph ase. Th is strategy m ay also be appropriate in th e set t ing of a m ore m at ure lesion in a less accessible location. With further m at urit y com es greater collagen deposition an d, con sequen tly, a capsule m ore con sisten t w ith th at of a m etastat ic lesion . Con siderat ion m ay be given to drain age—w ith resect ion of capsule—in th e case of a m at ure an d accessible lesion . This is generally feasible after 2 w eeks. Th e size of th e lesion also m ay in uen ce t reat m en t st rategies. It h as been suggested th at abscesses of a cert ain size (1.7 cm or less) m ay be t reated by m edicat ion alon e, w hereas lesion s of greater th an 2.5 cm rarely resolve w ith ou t surgical in ter ven t ion .9,12 Medical th erapy alon e m ay be con sidered in cases of m u lt ifocal disease, lesion s in eloquen t areas, con com it an t m en ingit is,
• •
• • • • • •
t ion regarding lesion locat ion , th e degree of associated edem a/m ass e ect , an d bony involvem en t . Cerebrit is w ill ap pear as a n on sp eci c region of hypoden sit y. A m ore m at u re ab scess w ill d em on st rate ring-en h an cem en t w ith associated p erilesion al edem a. CT of th e sin u ses (w ith coron al an d sagit t al recon st ruct ion s) m ay be a n ecessar y adju n ct if con t iguous exten sion is su sp ected. MRI brain pre- an d p ost-gadolin iu m m ay provide add it ion al in form at ion to assist diagn osis an d th erap eut ic in ter ven t ion s. MRI m ay de n e th e st age of abscess or cerebrit is. In cases of epidural or subdural em pyem a, m agn et ic reson an ce ven ograp hy (MRV) w ill de n e th e exten t of sin u s th rom bosis, if presen t . Magn et ic reson an ce di usion im ages are u seful in diagn osing subdural em pyem a, w h ich often sh ow s hyperin ten se sign al in dicat ing di usion rest rict ion .14 Magn et ic reson an ce spect roscopy or posit ron em ission tom ograp hy m ay h elp dist ingu ish an in fect iou s from a n eoplast ic process. Lum bar pun ct ure gen erally is n ot n ecessar y an d, w h en a m ass lesion is p resen t , m ay be con t rain dicated. Given p hysical separat ion from th e subarach n oid space, cerebrospin al u id sh ou ld be sterile (perh ap s w ith n on sp eci c in am m ator y ch anges) in th e set t ing of epidural em pyem a. Blood cu lt u res sh ou ld be draw n (p referably p rior to in it iat ion of an t im icrobial th erapy). In th e set t ing of bacterem ia, an ech ocardiogram is in d icated to exclu de en docardit is as th e et iology for in t racran ial in fect ion . HIV test ing sh ou ld be u n dert aken as th e spect ru m of in fect ious path ology (an d th e approach to t reat m en t) in th e im m u n ocom prom ised p opu lat ion m ay di er. A ch est X-ray sh ould be com pleted. A puri ed protein derivat ive skin test sh ould be placed if t ubercu losis is suspected. A pan oram ic X-ray m ay de n e an odon tologic et iology for in t racran ial in fect ion . Preoperat ive im aging (Fig 20.1a–f).
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III Nontraum atic Em ergencies
a
b
c
e
d
f
Fig 20.1a–f Axial CT (a) soft tissue and (b) bone windows, as well as (c) sagit tal MRI post-gadolinium T1-weighted image demonstrating a Pot t’s pu y tumor. Note the extracranial soft tissue collection in communication with the epidural space, via the frontal air sinus. (d) Axial MRI postgadolinium T1-weighted image demonstrating a right frontal subdural empyema. (e) The di usion-weighted imaging sequence, in this set ting, demonstrates hyperintense signal, indicating di usion restriction. (f) Axial MRI post-gadolinium T1-weighted image demonstrating an intracerebral abscess with loculations and peripheral enhancem ent, extending to the local meninges.
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Medication • Em piric, broad-spect rum an t im icrobial th erapy sh ould be
• •
in it iated at th e t im e of presen t at ion . Th e source, an d th erefore likely path ogen s, sh ou ld be con sidered. Th e au th or prefers a regim en of van com ycin , ceft riaxon e (cefep im e if a n osocom ial in fect ion is su sp ected), an d m et ron idazole, bearing in m in d th at th e sp eci c clin ical circu m stan ces of a given case m ay dictate m odi cat ion of th is regim en an d /or th e addit ion of an t ifungal or an t it uberculous coverage. In cases w h ere th e p ath ogen is kn ow n , t argeted an t im icrobial th erapy is th e goal. Corticosteroid therapy m ay be considered on an individual case basis for m anagem ent of accom panying vasogenic edem a. W hile the use of corticosteroids has been show n to be of som e
•
Surgery for Acute Intracranial Infection
bene t in the set ting of m eningitis,15 there exists no sim ilar established role for steroids in th e prim ar y m edical m an agem en t of abscess. Seizu res are com m on in th e set t ing of in t racran ial in fect ion . An t iepilept ic drug prophyla xis sh ould be in it iated upon p resen t at ion .
Operative Field Preparation • Th e h air is cropped (n ot sh aved) w ith an elect ric razor at th e • •
p lan n ed surgical site. Th e skin is prepared in it ially w ith alcoh ol, follow ed eith er w ith a st an dard povidon e iodin e or ch lorh exidin e scru b. Th e plan n ed in cision site is in lt rated w ith 1%lidocain e w ith 1:100,000 epin eph rin e.
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Operative Procedure Positioning (Fig. 20.2a, b)
a
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Surgery for Acute Intracranial Infection
b
Figure
Procedural Steps
Pearls
Fig. 20.2
(a) Patient positioning w ill depend upon the ultimate surgical target. In the majority of cases, a supine position—w ith varying degrees of head turn—w ill be appropriate. Posterior fossa pathology may be approached in the prone position. The head should be clamped in three -point pin xation. All pressure points should be padded.
• Infectious processes arising in the frontal sinus often extend contiguously to the frontal lobe. Mastoid-related processes generally track to the adjacent temporal fossa or posterior fossa.
(b) The surgical target w ill dictate the planned incision. (A) For pathology involving the frontal lobes, anterior skull base, and/or anterior falx, a bicoronal incision is appropriate. (B) For temporal lobe pathology, a pterional or rocking chair-type incision is appropriate. (C) Posterior fossa, petrous-associated pathology may be approached via a paramedian linear or hockey stick incision. For simplicity, the subsequent steps w ill assume a bicoronal approach.
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Incision (Fig. 20.3a, b)
b
a
Figure
Procedural Steps
Fig. 20.3
(a) An incision is planned extending from tragus to tragus, just posterior to the hair line. (b) A no. 10 blade is used to initiate the skin opening. The incision initially is carried dow n to the level of pericranium centrally and temporalis fascia laterally. Hemostatic scalp clips are applied to the skin edges. The scalp ap is re ected forw ard until the orbital rim and root of zygoma are palpable bilaterally.
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Surgery for Acute Intracranial Infection
Pericranial Flap Harvest (Fig. 20.4)
Figure
Procedural Steps
Fig. 20.4
A no. 15 blade is used to open the pericranium bilaterally just superior and parallel to superior temporal line ; a third, transverse cut is made at the level of coronal suture. A periosteal elevator is used to advance the ap forw ard to the level of the superior orbital rim. The vascularized ap is w rapped in a saline moistened sponge and secured temporarily w ith 4-0 braided nylon sutures under minimal tension.
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Division of the Temporalis and Bur Holes (Fig. 20.5)
Figure
Procedural Steps
Pearls
Fig. 20.5
Division of the temporalis muscle and fascia generally is not necessary for an approach to the frontal lobe/frontal air sinus. The author does create a cu in the fascia and muscle just inferior and parallel to superior temporal line, allow ing for placement of bur holes at the key hole and most posteriorly, at the level of the coronal suture.
• If access to the temporal fossa is
The position of the bone ap, too, will depend on the location of the target pathology. A rectangular frontal bone ap will address frontal lobe and unilateral frontal sinus pathology. If pathology is present along the bilateral falx, a mirror image bone ap may be necessary over the contralateral frontal lobe, leaving a strip of bone along the midline sagittal sinus. For a unilateral frontal bone ap, holes may be placed w ith a high speed drill at three points: (1) the keyhole, (2) at the level of coronal suture and just inferior to superior temporal line, and (3) just anterior to coronal suture and lateral to midline. Bone w ax is applied to the bony edges. A Pen eld no. 3 is used to strip the dural attachments from the undersurface of the calvarium betw een each set of bur holes.
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•
necessary, an additional vertical opening can be m ade from the midpoint of the cu to the root of zygom a (creating a T). The resultant aps m ay be re ected anteriorly and posteriorly, respectively. The strategic placem ent of t wo bur holes and subsequent ushing of the epidural space with antibiotic irrigation bet ween the holes m ay be considered in the case of a very sm all epidural collection.
20
Surgery for Acute Intracranial Infection
Elevation of the Bone Flap (Fig. 20.6)
Figure
Procedural Steps
Fig. 20.6
The craniotome is used to create a roughly rectangular bone ap. A periosteal elevator or Pen eld no. 3 is used to elevate the bone ap aw ay from the underlying dura. The dural surface is irrigated w ith saline. Hemostasis is attained w ith bipolar electrocautery. Bleeding attributable to the midline sinus may be controlled w ith brillar hemostatic material and/or gelatin foam soaked in thrombin. Epidural tacking stitches may be used to augment these techniques. If epidural abscess is present, proceed to the next step. If not, proceed to “Dural Opening and Addressing Subdural Empyema” (Fig. 20.8).
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Addressing Epidural Abscess (Fig. 20.7)
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Figure
Procedural Steps
Pearls
Fig. 20.7
Epidural abscess, if present, w ill be evident immediately upon elevation of the bone ap (if not at the time of bur hole placement). Direct communication w ith an adjacent air sinus and/or the orbit may be observed via gross erosion of bone. Liquid purulent material may be captured in a suction trap. Often, there is a friable, in ammatory pannus adherent to the dural surface. A Pen eld no. 2 or Oberhill periosteal may be used (gently) to scrape this layer aw ay from the underlying dura. A drain may be left in the epidural space and brought out through one of the posterior bur holes to a skin exit site, posterior to the scalp incision. Here, the drain is secured w ith a 3-0 nylon stitch. If no deeper infection is suspected, proceed to “Dural Closure and Cranialization of Frontal Sinus” (Fig. 20.11).
• Specim ens should be obtained for stat Gram stain,
•
•
aerobic, anaerobic, acid-fast bacilli, and fungal culture. Where feasible, collect tissue and/or uid as the diagnostic yield m ay exceed that of swabs alone. Great care must be taken to avoid perforating otherwise intact dura. Bleeding is best controlled with bipolar electrocautery. The epidural space should be irrigated with large volumes of antibiotic solution. The dura should be inspected but not opened unless there is a strong suspicion for a subdural component to the infectious process. Intentional or unintentional breach of the dura m ay result in seeding the deeper compartm ents with infection.
20
Surgery for Acute Intracranial Infection
Dural Opening (Fig. 20.8)
Figure
Procedural Steps
Fig. 20.8
The dural opening w ill depend on the position of the bony defect. In the setting of a frontal craniotomy, a no. 15 blade is used to initiate a trap door–type opening that may be apped tow ard the midline sagittal sinus. A mirror image opening is made if a bifrontal craniotomy is present.
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III Nontraum atic Em ergencies
Addressing Subdural Empyema (Fig. 20.9)
342
Figure
Procedural Steps
Pearls
Fig. 20.9
Subdural empyema, if present, w ill be visualized upon elevation of the dural ap. Once again, liquid purulent material may be collected in a suction trap. Gentle retraction of the frontal pole w ill permit access to the frontal oor. Gentle depression/retraction of the superior frontal gyrus w ill permit access to the falx. The subdural space should be explored in all directions under direct visualization and irrigated w ith antibiotic solution to ush out any remaining purulent material. An in ammatory pannus may be adherent to the pia. If no deeper infection is suspected, proceed to “Dural Closure and Cranialization of Frontal Sinus” (Fig. 20.11).
• The developm ent of brain swelling m ust be
•
anticipated upon evacuation of subdural empyem a. If subdural empyem a is suspected, a large bone ap should be planned. Likewise, the dura m ay be opened initially via multiple linear radiations from a central point. In cases of parafalcine empyema, Nathoo advocates an initial drainage via parasagit tal craniectomy—prior to craniotomy—to help prevent acute, m assive swelling.16 The exudative m embrane should not be disturbed as at tempted debridement m ay result in cortical injury and/or hem orrhage.
20
Surgery for Acute Intracranial Infection
Approaching Intraparenchymal Abscess—Open Craniotomy (Fig. 20.10)
Figure
Procedural Steps
Pearls
Fig. 20.10
To approach an intraparenchymal abscess, the sulcus overlying the abscess is opened; the abscess cavity typically lies at the base of the sulcus. A blunt brain needle may be introduced under ultrasound or image guidance into the abscess cavity for immediate drainage. The blunt needle may be exchanged for an external ventricular drain catheter, allow ing for continued drainage and/or instillation of antibiotic agents. The capsule may be dissected aw ay from the surrounding w hite matter. The capsular plane is follow ed circumferentially until the lesion has been “shelled out.” The site then is irrigated w ith antibiotic solution and hemostasis attained w ith bipolar electrocautery as w ell as various hemostatic agents.
• An open approach is indicated for an easily accessible
• • •
lesion with a well-developed capsule, in a noneloquent area. Abscesses secondary to fungal infection and/or foreign body may be m edically refractory. If the abscess is not visible along the cortical surface, ultrasound or im age guidance m ay be used to determine the best trajectory for approach. The surrounding tissue is often friable and bleeds easily. Particular care m ust be taken with periventricular lesions where the capsule wall m ay be thinner. Consideration should be given to aspiration alone, given the risk of intraventricular rupture with at tempted resection.
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III Nontraum atic Em ergencies
Dural Closure and Cranialization of Frontal Sinus (Fig. 20.11)
Figure
Procedural Steps
Pearls
Fig. 20.11
If feasible, primary closure may be accomplished w ith interrupted 4-0 braided nylon stitches. If grafting is necessary, it is preferable to incorporate autologous materials in the setting of infection. Pericranium, temporalis fascia, or fascia lata (the latter requiring the foresight to prepare the lateral thigh preoperatively) are good options.
• Prim ary dural closure m ay not be
In cases of contiguous extension of infection from the frontal air sinus to the epidural and/or subdural space, it is necessary to cranialize the frontal sinus prior to closure. The dura should be dissected from the roof of the orbit and posterior w all of the frontal sinus (if not already done by the abscess itself). The posterior table should be drilled ushed w ith the frontal fossa oor. Mucosa should be stripped from the sinus and the inner surface of the sinus, in turn, decorticated w ith a diamond bur. The sinus then is packed. The nasofrontal duct is obliterated. The previously harvested, vascularized pericranial ap then is folded dow n over the sinus opening and secured to the native dura at multiple points w ith 4-0 braided nylon stitches. A layer of brin glue is applied to the suture line.
344
•
•
feasible in the set ting of m alignant cerebral edem a. Autologous graft material m ay be tacked loosely at the edges to accom m odate swelling. In extrem e circum stances, a large piece of dural substitute m aterial m ay be laid over the dural defect. The author uses dry pieces of gelatin sponge coated with bacitracin powder for packing of the frontal sinus. Alternately, adipose tissue (from a peripheral site) or m uscle (temporalis) may be used. See Chapter 27 for additional discussion of techniques for frontal sinus reconstruction.
20
Surgery for Acute Intracranial Infection
Approaching Intraparenchymal Abscess—Stereotactic (Fig. 20.12a–c)
a
345
III Nontraum atic Em ergencies
b
346
c
Figure
Procedural Steps
Pearls
Fig. 20.12
(a) Using framed or frameless stereotaxy, a small skin opening is planned to allow for access to the abscess cavity along a de ned trajectory. A single bur hole is placed at the planned entry site. The underlying dura is coagulated w ith bipolar electrocautery and opened in a cruciate fashion w ith a no. 11 blade. The dural lea ets again are coagulated. The underlying arachnoid-pia is coagulated and opened sharply. (b) Frameless stereotactic planning for needle aspiration of a right frontal deep intraparenchymal abscess. (c) An external ventricular drain or blunt brain needle is passed along the predetermined image guidance trajectory until the abscess cavity is entered. Liquid purulent material is collected by gravity drainage and gentle aspiration. The catheter may be irrigated gently, taking care that the amount of uid entering is observed to drain by gravity. The catheter may be left in place and brought out to a skin exit site, remote from the scalp incision. Here, the drain is secured w ith a 3-0 nylon stitch. The bur hole site is irrigated w ith antibiotic solution. The scalp is closed in tw o layers (see Closing).
• A stereotactic approach is indicated for aspiration • • •
•
of less m ature lesions, deep lesions, and lesions adjacent to eloquent areas. If im age guidance is not available, ultrasound m ay be used in conjunction with a slightly larger bony opening. Multiple lesions or m ultiple loculations within an abscess m ay require m ultiple entry point s for aspiration. Passage of a needle through thickened leptom eninges, without opening of the arachnoidpia, may result in subdural bleeding as cortex is pushed away from the calvarium . The “best” trajectory is de ned as the shortest route to the pathology that bypasses eloquent areas and vital structures.
20
Closing
Surgery for Acute Intracranial Infection
out put s becom e m in im al an d/or serial im aging dem on st rates resolu t ion of th e t argeted collect ion .
• If th ere is rad iograp h ic an d/or gross eviden ce of osteom yelit is • • • •
• • • • •
involving th e bon e ap, it sh ou ld n ot be reim plan ted. Likew ise, if m align an t cerebral ed em a is presen t , th e bon e ap sh ou ld n ot be reim p lan ted. In oth er circu m st an ces, th e bon e ap m ay be reapp roxim ated u sing a p late an d screw system . Th e in cision site is irrigated w ith an t ibiot ic solut ion . Hem ostasis is at t ain ed w ith a com bin at ion of bipolar elect rocauter y an d h em ost at ic agen t(s) of ch oice. Epidural t acking st itch es are placed circu m feren t ially arou n d th e cran iotom y defect w ith 4-0 braided nylon sut ure. A no. 7 Jackson -Prat t drain is laid in th e subgaleal space an d brough t out to a skin exit site just posterior to th e scalp in cision . Here, th e drain is secu red w ith a 3-0 nylon st itch . Th e tem poralis cu is reapproxim ated w ith 0-absorbable braided sut u re in terru pted st itch es. Th e scalp ap is released from ret ract ion . Hem ostat ic scalp clips are rem oved from th e skin edges an d h em ost asis att ain ed, w h ere n ecessar y, w ith bipolar elect rocauter y. Th e galea an d subcutan eous t issue are reapproxim ated w ith 0-absorbable braided su t ure inver ted st itch es. Th e skin is closed w ith a run n ing 3-0 nylon st itch or staples.
Medication • Em piric, broad-spect rum antim icrobial therapy should be con -
• • •
Radiographic Imaging • Early post procedure CT im aging is in dicated to assess th e
Postoperative Management Monitoring
•
• Pat ien t s sh ou ld be m on itored in th e in ten sive care u n it set• •
t ing follow ing operat ive in ter ven t ion . Th e use of invasive n eurologic m onitors (in t raparen chym al or in t raven t ricu lar) is approp riate for pat ien t s in w h om serial n eu rologic exam is n ot feasible. Th e ou t put of epidural an d/or subdural drain s, if presen t , sh ou ld be m on itored . Drain rem oval m ay be con sidered w h en
a
t inued pending cult ure results and then narrow ed accordingly to provide targeted th erapy for th e iden ti ed path ogen (s). Generally, a 4- to 6-w eek course of intravenous an t im icrobial therapy is prescribed. Som e advocate a 6- to 8-w eek course for intracerebral abscess.16 Longer-term therapy m ay be in dicated for select organism s (e.g., Mycobacterium tuberculosis). Steroid th erapy sh ou ld be tapered rap idly in accordan ce w ith evolving clin ical exam an d eviden ce of resolving edem a/m ass e ect per serial im aging. An t iepilept ic drug (AED) prophylaxis sh ould be con t in ued in cases w h ere docu m en ted seizure act ivit y is presen t . Oth erw ise, AEDs m ay be t apered o in th e postoperat ive period. Pat ien t s w ith eviden ce of in creased in t racran ial pressu re m ay require addit ion al m edical th erapies for m an agem en t .
•
e cacy of debridem en t as w ell as to ru le ou t h em orrh age, isch em ia, an d hydrocep h alus. Im aging sh ould be repeated at in ter vals during th e im m ediate postoperat ive cou rse as n eu rologic stat u s w arran ts. MRI m ay be u sed for longer-term follow -u p , bearing in m in d th at MRI en h an cem en t m ay persist for m on th s despite clin ical im provem en t an d appropriate an t im icrobial th erapy. MRI m ay be em p loyed for m ore d etailed ch aracterizat ion of st ru ct ural path ology in th e acute set t ing, as w ell as for serial t racking of respon se to th erapy (bearing in m in d th at radiograph ic ch ange often lags beh in d clin ical im provem en t). Postoperat ive im aging (Fig. 20.13a, b). A CT scan is obt ain ed in th e im m ediate p ostop erat ive period for in ter val assessm en t
b
Fig. 20.13a, b (a) Non-contrast CT scan demonstrating local craniectomy and debridement of epidural abscess for the patient depicted in Fig. 20.1a–c. (b) Post-gadolinium T1-weighted axial image demonstrating resolution of intracerebral abscess and associated meningeal enhancement for the patient depicted in Fig. 20.1f.
347
III Nontraum atic Em ergencies of m ass e ect , edem a pat tern , an d ven t ricular size, as w ell as to exclu de h em orrh age.
Further Management • Reaccum ulat ion of epidu ral, su bdural, an d in t raparen chym al •
collect ion s m ay occur. Pat ien ts m ay require m ult iple operat ive in ter ven t ion s for debridem en t . In th e set t ing of in t raven t ricu lar ru pt u re of an abscess, p lacem en t of an extern al ven t ricu lar drain is app ropriate to p erm it con t in uou s drain age of cerebrospin al uid, as w ell as in t rath ecal adm in ist rat ion of ant im icrobial th erapy.
Special Considerations • If in fect ion arises from th e sin u ses or m astoid p rocess, si-
• •
m u ltan eou s m an agem en t of th e in fect iou s p ath ology by Otolar yngology m ay be in dicated. Otolar yngology sh ou ld be involved in th e p reoperat ive p lan n ing for such cases. Form al In fect ious Diseases con sultat ion is appropriate to gu ide an t im icrobial th erapy. Suppurative intracranial throm bophlebitis is a feared com plication of central nervous system infection. Suppurative throm bophlebitis m ay begin w ithin the veins or venous sinuses or m ay occur after infection of the paranasal sinuses, m iddle ear, m astoid, or oropharynx. MRI of the brain, w ith MRV, is the test of choice. A 3 to 4 week course of intravenous antim icrobial therapy is recom m ended. The use of anticoagulation in this setting is controversial.17 It is also im portant to note that relapse m ay occur w ithin 6 weeks—after apparent clinical resolution—and abscess form ation has been reported up to 8 m onths later.18
References 1. Dill SR, Cobbs CG, McDon ald CK. Su bdu ral em pyem a: an alysis of 32 cases an d review. Clin In fect Dis 1995;20:372–386 2. Flam m ES. Percivall Pot t: an 18th cen t u r y n eu rosu rgeon . J Neu rosurg 1992;76:319–326 3. Hall WA. Cerebral in fect iou s p rocesses. In : Loft u s CM, ed . Neu rosurgical Em ergen cies. Vol. 1. Park Ridge, IL: Am erican Associat ion of Neurological Surgeon s Publicat ions; 1994: 165–182
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4. Nath oo N, Nadvi SS, van Dellen JR, Gouw s E. In t racran ial su bdu ral em pyem as in th e era of com puted tom ography: a review of 699 cases. Neurosurger y 1999;44:529–535 5 . Har t m an BJ, Helfgot t DC, We in gar t e n K. Su b d u ral em pyem a an d su p p u rat ive in t racran ial p h lebit is. In : Sch eld W M, W h it ley RJ, Mar ra CM, e d s. In fe ct ion s of t h e Cen t ral Ner vou s Syst e m . Ph ilad elp h ia: Lip p in cot t W illiam s & W ilkin s; 2 0 04 : 52 3 – 53 6 6. Riech ers RG, Jarell AD, Ling GSF. In fect ion of th e cen t ral n er vou s system . In : Suarez JI, ed. Crit ical Care Neurology an d Neurosurger y. New York: Hum an a Press; 2004: 515–532 7. Yang S-Y. Brain abscess: a review of 400 cases. J Neu rosu rg 1981;55:794–799 8. Math isen G, Joh n son JP. Brain abscess. Clin In fect Dis 1997; 25:763–779. 9. Tu n kel AR. Brain abscess. In : Man dell GL, Ben n et t JE, Dolin R, eds. Prin ciples an d Pract ice of In fect ious Diseases. 6th ed. Ph iladelph ia: Elsevier; 2005: 1150–1163 10. Nath oo N, Nadvi SS, Gouw s E, van Dellen JR. Cran iotom y im proves ou tcom es for cran ial su bd u ral em pyem as: Com p u tedtom ograp hy era experien ce w ith 699 p at ien t s. Neu rosu rger y 2001;49:872–878 11. Brit t R, En zm an n D. Clin ical st ages of h u m an brain abscesses on serial CT scans after con t rast in fusion . J Neurosurg 1998;59: 972–989 12. Oban a WG, Rosen blu m ML. Non op erat ive t reat m en t of n eu rosurgical in fect ion s. Neurosurg Clin N Am 1992;3:359–373 13. Rosen blu m M, Ho J, Norm an J, Edw ards M, Berg B. Non op erat ive t reat m en t of brain abscesses in select h igh -risk pat ien t s. J Neu rosu rg 1980;52:217–225 14. Wong AM, Zim m erm an RA, Sim on EM, et al. Di u sion -w eigh ted MR im aging of su bdu ral em pyem as in ch ildren . AJNR Am J Neu roradiol 2004;25:1016–1021 15. Tu n kel AR, Har t m an BJ, Kaplan SL, et al. Pract ice gu idelin es for th e m an agem ent of bacterial m en ingit is. Clin In fect Dis 2004;39:1267–1284 16. Kasten bau er S, P ster H-W, W h isp elw ey B, et al. Brain abscess. In : Sch eld W M, W h itley RJ, Marra CM, eds. Infect ion s of th e Cen t ral Ner vou s System . Ph iladelp h ia: Lipp in cot t William s & Wilkin s; 2004: 479–508 17. Bh at ia K, Jon es NS. Sept ic cavern ou s sin u s th rom bosis secon dar y to sin u sit is: are an t icoagu lan t s in dicated ? A review of th e literat ure. J Lar yngol Otol 2002;116:667–676 18. Tu n kel AR. Su bdu ral em pyem a, epid u ral abscess, an d su p purat ive in t racran ial throm boph lebit is. In : Man dell GL, Ben n et t JE, Dolin R, eds. Prin cip les an d Pract ice of In fect iou s Diseases. 6th ed. Ph iladelph ia: Elsevier; 2005: 1164–1171
21
Ventricular Shunt Malfunction Sergey Abeshaus, Sam uel R. Brow d, and Richard G. Ellenbogen
Introduction A ven t ricu lar sh u n t (VS) m alfu n ct ion is a com m on n eu rosu rgical em ergen cy. In fact , a sh un t revision is on e of th e m ost com m on p roced u res a n eu rosu rgeon m ay perform . It is est im ated th at up to 50% of sh un t s m ay fail w ith in 2 years. Despite it s ap paren t sim plicit y, a sh u n t revision requ ires m et icu lou s atten t ion to detail an d vigilan ce in diagn osis an d m an agem en t to en su re th e pat ien t is t reated in a t im ely an d adequ ate m an n er. Th e w orku p an d su rgical t reat m en t of a VS m alfu n ct ion is fraugh t w ith risks an d com plicat ion s even in th e m ost exp erien ced h an ds. In th e Un ited St ates, sh u n t revision costs are h igh , perh aps over $1 billion a year. Th e h um an costs are st aggering. Com m on causes of sh un t m alfun ct ion in clude m ech an ical failu re (obst ru ct ion , discon n ect ion , or m igrat ion ), h ardw are failure (valve), in fect ion , fun ct ion al (u n derdrain age or overdrain age), or a com bin at ion of th ese aforem en t ion ed issues.1,2 A t ypical clin ical presen t at ion of an acu te VS m alfu n ct ion in clu des drow sin ess, severe h eadach es, an d vom it ing.3 How ever, th e presen t at ion m ay be qu ite d iverse, from rap id to slow / su btle an d ch ron ic. Th e com m on sign s an d sym ptom s m ay be as m od est an d in con sp icu ou s as d eteriorat ion in sch ool perform an ce, irritabilit y, in crease in h ead circu m feren ce over th e 95th percen t ile, in creased leth argy or sleep, clu m sin ess, ch ron ic m alaise, ch ron ic fever, abdom in al pain , or sw elling aroun d th e sh un t t ract . More im pressive presen tat ion s in clude seizu re, cran ial n er ve paresis (III, IV, or VI), decrease in visual acuit y, p aralysis of u pw ard gaze, papilledem a, w eakn ess or paralysis, st u por, com a, or ch ange in vital sign s (decreased p u lse or in creased m ean arterial pressu re). Obt ain ing m et icu lou s in form at ion from a p at ien t or h is/h er caregiver or th e m edical records about th e t ype of sh un t im p lan ted an d previou s sh un t failure presen tat ion is im port an t . Previou s im aging, especially w h en don e during sym ptom -free p eriod, is vital in su rgical decision m aking. Kn ow ledge of th e t yp e of sh u n t an d in form at ion abou t th e set t ing, date, an d sp eci cs of previous operat ion s m ay in u en ce t reat m en t st rategy in com p lex cases. How ever, th ese det ails m ay often be in com p lete. It is im p or tan t to n ote th at a sh un t can m alfun ct ion w ith out cau sing an obvious ch ange in ven t ricular size, in part , du e to poor com plian ce of th e brain . How ever, th e in t racran ial pressu re (ICP) can be elevated an d on ly th e h istor y from th e pat ien t or fam ily m em ber, sym ptom s, or exam m ay be h elpfu l. In th ose p at ien t s w h ose scan s m ay n ot ch ange during a t yp ical sh u n t m alfu n ct ion , it is im p erat ive to listen to th e h istor y provided by a know ledgeable caregiver w h o can accurately com pare th is
presen t at ion w ith th at of a previous sh un t m alfun ct ion . Failure to do so m ay be cat ast roph ic. Th e steps in w orking up a ven t ricular sh un t m alfun ct ion : 1. Obtain inform at ion about the underlying et iology of hydrocephalus treated by initial shunt placem ent. In our experience, over 90%of patien ts h ave hydroceph alus from in t raven t ricular hem orrhage (IVH) of prem at urit y, infect ion, t raum a, t um or, norm al pressure hydrocephalus (NPH), past hem orrh age, aqueductal stenosis, or congenital etiology (m yelom eningocele, craniofacial, or genet ic). In about 10% of patients the et iology is unclear. This histor y m ay be especially im portant in cases of aqueductal stenosis, in w hich a patient m ay undergo an en doscopic th ird ven triculostom y (ETV), in stead of a sh un t revision. 2. Determ in e th e t ype of th e VS. Th e m ost com m on are ven t riculoperiton eal, ven t ricu loat rial, an d ven t riculopleural sh u n ts; t yp e of valve (m aker, m odel, xed p ressure or adju st able [n eed to verify last pressure set t ing]); side of th e sh un t im plan t at ion ; an d date an d t ype of recen t in ter ven t ion s on sh un t system . Th ere are a variet y of sh un t valves currently available at th e m arket (please refer h t t p://w w w.pedsn eurosurger y.org/ ed u cat ion .asp for fu r th er in form at ion ).
Indications • Clin ical sym ptom s of sh un t m alfun ct ion su ch as th ose listed in th e in t rodu ct ion • Radiological sym ptom s of sh u n t m alfu n ct ion w ith ven t ricu lar dilatat ion • Posit ive cerebrosp in al u id (CSF) cu lt u res, posit ive eviden ce of m icroorgan ism or elevated w h ite coun t con sisten t w ith in fect ion , an d oth er possible clin ical scen arios described elsew h ere 1,2 • Discon t in u it y in sh u n t t u bing or d islodgem en t of t u bing from ven t ricle or abdom en (VP), pleu ra (Vp leu ral), or h ear t (VA) • Exposure of sh un t t u bing • Sh u n t explorat ion w ith ou t ven t ricu lom egaly in p at ien t w h o h as poor com plian ce of brain , an d p resen ts w ith sign s an d sym ptom s of in creased in t racran ial pressu re • Slit-ven t ricle w ith in term it ten t sh u n t m alfu n ct ion • Desire to convert sh u n t p at ien t in to a sh u n t-free p at ien t by an ETV, in th e face of a sh u n t obst ru ct ion Th ere is a sim pli ed algorith m for decision m aking in ven t ricular sh un t m alfun ct ion in Fig. 21.1.
349
III Nontraum atic Em ergencies
Evalu ate for Sh un t Malfu n ct ion
Sh un t Tap
Yes
Fever > 38.4, sh un t su rger y in past 6 m on th s or p osit ive blood cu lt ure
Posit ive
Negat ive
No
Sh u n t Extern alizat ion + ABx
Pseu docyst
No
Sh u n t Revision
Yes
Sh u n t Extern alizat ion + ABx
Fig. 21.1 Simpli ed algorithm for decision making in ventricular shunt malfunction.
Preprocedure Considerations Radiographic Imaging • Head com p u ted tom ograp hy (CT; m ay be com bin ed w ith •
•
ducial m arkers for n avigat ion ) (Fig. 21.2a). Rap id sequ en ce brain m agn et ic reson an ce im aging (MRI; Haste T2 protocol) 4 (Fig. 21.2b)—fast , gen erally n o n eed for an esth esia/sedat ion . Th e rat ion ale for u sing a fast T2w eigh ted abbreviated MRI exam is to avoid th e radiat ion risk from cu m u lat ive CT scan s. Sh u n t series—X-ray: Head an d n eck an terop osterior (AP) an d lateral (Fig. 21.3a, b), ch est AP an d lateral, abdom en an d p elvis AP (Fig. 21.3c) an d lateral. Abdom en an d pelvis
•
radiography is n ot n ecessar y in case of ven t ricu loat rial or ven t ricu lopleu ral sh u n t evalu at ion .5 Sh u n togram (radion u clide) p rovides som e in form at ion regarding op en ing p ressu re an d sh u n t ow. Radion u clide sh u n togram sh ou ld be con sidered in p at ien ts w h ose h istor y, CT scan , or exam is n ot de n it ive an d sh u n t ow ch aracterist ics n eed to be evalu ated to decide w h eth er or n ot to operate. A radion uclide st udy sh ould n ot delay revision in th e set t ing of an acute, obvious m alfun ct ion .
Diagnostic Procedures • Sh un t tap—if th e fever is greater th an 101° F or th ere is a p osit ive blood cult ure in last 48 h ours an d/or sh un t system in ter-
a
b Fig. 21.2a, b Preoperative imaging of shunt malfunction of the same patient. (a) Head CT and (b) brain MR (Haste T2 protocol).
350
21
Ventricular Shunt Malfunction
a
c
b
Fig. 21.3a–c Shunt series. (a) Anteroposterior (AP) and (b) lateral skull showing ventricular catheter disconnection. (c) AP abdom en showing distal catheter disconnection (arrow).
ven t ion w ith in 6–12 m on th s, p roceed w ith sh u n t t ap p rior to revision . Over 95% of all sh u n t in fect ion s occu r w ith in 1 year of th e last sh un t in st rum en t at ion , w ith th e m ajorit y of th em occurring w ith in 3 m on th s.
Medication Antibiotics • Any n ew sh un t placem en t or revision : t w o doses of cefazolin
•
or any late gen erat ion ceph alosporin ; rst dose is adm in istered during an esth esia in duct ion (45 m in utes to 1 h our prior to th e in cision ) an d th e secon d dose after th e surger y w ith in 8 h ours. Som e surgeon s cover th e pat ien ts w ith an t ibiot ics for 24 h ou rs; h ow ever, th e eviden ce m ostly su pp or t s a single p reoperat ive dose p rior to skin in cision . Con sid er van com ycin 1 h ou r in advan ce of surger y in m eth icillin -resistan t Staphylococcus aureus–colon ized pat ien t s. Sh u n t in fect ion : tap sh u n t , th en im m ed iately begin t riple an t ibiot ics (ceft riaxon e, van com ycin , an d m et ron idazole in
com m u n it y-acquired an d im ipen em /cilast in in stead of ceft riaxon e in h ospit al-acqu ired in fect ion ).6
Operative Field Preparation Preparat ion is don e according to follow ing th e Hydroceph alus Clin ical Research Net w ork (HCRN) p rotocol adopted for Seat tle Ch ild ren’s Hospit al (Fig. 21.4).7 Position the patient w ith the head away from the door. Wide exposure is im portant. Hair is rem oved w ith clippers. Prelim inarily prepare the skin w ith chlorhexidine soap, then isopropyl alcohol, to rem ove any dirt or debris and allow to dry. Mark the incision. Previous in cision s on th e scalp m ay be exten ded to get ap propriate exposu re of ven t ricular cath eter an d sh u n t valve ( con sider vascular supply to scalp so as n ot to devascularize th e scalp ap). We use 2% ch lorh exidin e glucon ate/70% isopropyl alcoh ol solu t ion preparat ion for th e surgical eld an d w ait 3 m in utes or longer to dr y. Double gloves are advised. Drape w ith an t im icrobial in cise lm an d en sure isolat ion of poten t ial in fect ion sources (t rach eostom y, gast rostom y t ube, etc.).
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III Nontraum atic Em ergencies
Pat ien t in room
Sign on OR door rest rict ing t raffic
Posit ion head aw ay from th e m ain OR door
Ask for an t ibiot ics
Clip h air as n eeded
Dir t , d ebris, and adh esive m aterial rem oved
Ch lorap rep ap plied to su rgical field an d n ot w ash ed off
Wait 3 m in u tes
Han d scrub w ith betad in e or ch lorh exidin e
# w h o scru bbed # w h o w ash ed h an ds correctly
Dou ble gloves (n on -latex)
# w h o d ou ble-gloved
Ioban drape used
Yes
An t ibiot ics in ?
No
In cision , sh un t evalu at ion , revision
Wait
Inject ion of van com ycin /gen t am ycin in to shu n t reser voir
Closure
Dressing
Postoperat ive orders in clu de on e dose of sam e an t ibiot ic Fig. 21.4 HCRN protocol7 /Seat tle Children’s Hospital (SCH) protocol.
352
21
Ventricular Shunt Malfunction
Operative Procedure Shunt Revision Positioning and Preparation (Fig. 21.5)
Figure
Procedural Steps
Pearls
Fig. 21.5
The patient is placed supine w ith the head on a gel donut, head mildly rotated aw ay from valve site for adequate exposure of operative eld. A gel roll is placed under the shoulders to extend and maintain the appropriate plane for tunneling. Ensure appropriate foam or gel padding to reduce pressure sore risk at every pressure point.
• Som etim es in complex patients wound
•
preparation and draping m ay be challenging, such as those patients with chem otherapy catheters or gastrostomy tubes. It is important to change gloves before making the incision.
Alw ays expose w idely so that all parts of the shunt and tract (abdomen for the VPS, chest for ventriculoatrial or ventriculopleural shunt) are covered. In noninfected cases, incisions are in ltrated w ith 1%lidocaine w ith epinephrine 1:100,000.
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Skin Incision and Wound Dissection (Fig. 21.6a, b)
a
354
21
Ventricular Shunt Malfunction
b
Figure
Procedural Steps
Pearls
Fig. 21.6
Evaluate ventricular catheter skull entry site and valve location based on review of imaging, palpation, and navigation assistance. (a) An incision is made w ith a no. 10 or no. 15 blade often through a preexisting incision w ith extension along the valve for appropriate exposure of distal part of the valve. The incision should not be over the hardw are to avoid w ound breakdow n. After w e score the skin w ith a blade, w e use Bovie electrocautery dow n to and around the shunt hardw are because it does not cause harm to the valve or tubing. (b) The careful dissection of soft tissue in the galeal-pericranial plane to preserve pericranium and appropriate exposure of both ventricular catheter and valve is performed. Wound edges are retracted carefully w ith Weitlaner retractor(s) or retraction sutures. Wound hemostasis is obtained w ith monopolar or bipolar electrocautery.
• We use the needle tip monopolar •
electrocautery. One can utilize a custom tailored skin incision or curvilinear incision to provide adequate scalp coverage and release tension from the wound. In patients with a comprom ised scalp, the surgeon m ay need to perform a Z-plast y—a rotational ap or score the galeal layer to ensure adequate scalp coverage over the tubing without tension.
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Evaluation of Ventricular Catheter Reservoir (Fig. 21.7)
Figure
Procedural Steps
Pearls
Fig. 21.7
Carefully disconnect the ventricular catheter from the valve and assess CSF ow. If no ow, the catheter is replaced. If partial ow, connect the ventricular catheter to a manometer and obtain the opening pressure. If there is partial obstruction, so identi ed due to high ICP or no pulsatility in the CSF uid column then proceed w ith catheter revision.
• It is important to avoid pulling the
When extant, the side arm of the Rickham reservoir and valve are carefully dissected free. Disconnect the side arm of the Rickham reservoir from the valve to assess CSF ow. Use above algorithm for revision if no/reduced ow.
356
Rickham reservoir/ventricular catheter out (if adherent) to reduce risk of intraventricular bleeding.
21
Ventricular Shunt Malfunction
Revision of Ventricular Catheter (Fig. 21.8)
Figure
Procedural Steps
Fig. 21.8
During catheter revision, if the ventricular catheter is adherent to the choroid plexus in the ventricle, a monopolar w ire is used to release the catheter. It takes careful monopolar coagulation, gentle manipulation, or tw isting of the catheter until a burst of CSF signals the release of the catheter. We use a Jake clamp to hold the catheter during this maneuver. 8 If there is intraventricular blood, gently irrigate the ventricle via barbotage w ith normal saline or lactated Ringer’s until it clears.
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Placement of Ventricular Catheter (Fig. 21.9)
358
Figure
Procedural Steps
Pearls
Fig. 21.9
After removal of the old ventricular catheter, a new antibiotic impregnated or dotted ventricular9 catheter is placed w ith the catheter tip just anterior to ipsilateral foramen of Monro. We utilize stereotactic navigation to assist placement. 10 Alternatively, one can use anatomic landmarks, such as the mid-pupillary line and nasion, w ith the catheter insertion and trajectory perpendicular to the skull.
• Place a gloved nger in the hole im m ediately after rem oval of a ventricular catheter to prevent the CSF from leaking out which m ight reduce or shift the ventricle size thereby m aking catheter insertion challenging. Consider using intrathecal antibiotics according to HCRN protocol if the catheter is not antibiotic im pregnated.
21
Ventricular Shunt Malfunction
Evaluation of Valve and Distal Catheter (Fig. 21.10)
Figure
Procedural Steps
Pearls
Fig. 21.10
Follow ing revision of the ventricular catheter (or if it is found to be functioning and not revised), a manometer is connected to the proximal part of the valve to test distal run-o . If the pressure is appropriate according to the performance characteristics of the valve, then the proximal catheter is reconnected to the valve and secured w ith a 2-0 silk tie. If the pressure is higher than inspected, the valve is disconnected from distal tubing and the distal tubing is evaluated again w ith a manometer. The expected pressure is usually less than 5 cm H2 O. If found to be functional, the distal catheter is ushed w ith 1–2 mL of normal saline and the presumed compromised valve is replaced w ith a new one. The connections to the proximal and distal catheters are secured w ith 2-0 silk ligatures. If the distal catheter is obstructed, it is removed by gently pulling out as one piece through the cranial incision. If the distal catheter is adherent, the abdominal incision w ill need to be opened in an attempt to free the catheter. In rare cases w hen total removal of shunt in one piece is not possible, the abdominal incision is opened to remove the rest of the distal catheter.
• While reconnecting the parts of the shunt, it is important to ensure that there is no airlock in any part of the tubing including the valve.
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Revision of Distal Catheter (Figs. 21.11 to 21.15)
360
Figure
Procedural Steps
Pearls
Fig. 21.11
Subcostal approach: After removal of the distal (peritoneal) catheter, a super cial abdominal skin (linear) incision (usually at the site of the previous incision) is made by a no. 15 blade or needle tip cautery. The incision size depends on the patient’s age and body mass index. The incision is usually 10–20 mm in length but is tailored to the patient’s particular anatomic features. The surgeon holds the skin edges gently distracted so that the incision can be extended through the subcutaneous fat layer and deep membranous layer (Scarpa’s fascia) dow n to the anterior rectus sheath.
• There are several ways to replace the distal catheter in
•
cases of obstruction. Either a sm all abdom inal opening, blunt abdom inal trochar, or laparoscopic technique are perform ed.11,12 For obese patients, we prefer a laparoscopic approach. For an open approach, som e surgeons prefer a sub-xiphoid, vertical m idline incision, while others prefer a right-sided subcostal lateral incision. Both general approaches work well as long as the surgeon is fam iliar with the anatomy in the abdom en. We usually use the preexisting incision. The goal is to avoid multiple parallel incisions if possible.
21
Ventricular Shunt Malfunction
Figure
Procedural Steps
Fig. 21.12
The anterior rectus sheath is opened along the tissue bers and the rectus muscle is identi ed. Straight clamps are used to separate along the muscle bers. A self-retaining retractor is placed to keep the anatomic layers spread. The posterior rectus sheath can be gently elevated w ith an atraumatic toothed forceps and sharply opened w ith no. 15 blade or cautery. The incision may be extended w ith curved Metzenbaum scissors. After advancement of the retractor, the transversalis fascia is opened often revealing extraperitoneal fat.
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III Nontraum atic Em ergencies
362
Figure
Procedural Steps
Pearls
Fig. 21.13
The peritoneum is identi ed and elevated as betw een tw o Halsted mosquito clamps to avoid trapping the viscus below. Delicate scissors are used to create a small 5–7 mm incision into the peritoneum
• A Pen eld no. 4 dissector is gently introduced into the peritoneal cavit y to con rm entrance into this space. If the Pen eld no. 4 does not pass with ease, it is possible to be in a pre-peritoneal space. Once can often see bowel or liver to con rm presence in the peritoneal cavit y.
21
Ventricular Shunt Malfunction
Figure
Procedural Steps
Pearls
Fig. 21.14
The peritoneal catheter is tunneled subcutaneously through a passer and connected to the valve w ith a 2-0 silk tie.
• There are m any tricks to passing a shunt through the subcutaneous
The direction of tunneling is of surgeon preference. We prefer the tunneling from the peritoneal end tow ard the cranial direction in the majority of patients unless it is safer to tunnel from the cranial direction tow ard the peritoneum. There is no proven bene t to either tunneling technique.
track. One technique is to pass the shunt through the hollow end of the shunt passer while saline is irrigated through the tube from the other end. Another technique includes using a heavy 72-inch 2-silk ligature at the end of the shunt passer and pulling the silk through the subcutaneous track. The new tubing is tied to the silk ligature and pulled through the subcutaneous track as the silk is pulled toward the surgeon. Alternatively, a silk ligature could be placed on the old distal tubing and pulled through the subcutaneous track. The new tubing is tied to the end of the silk ligature and it is pulled toward the surgeon with the new tubing which is then laid in its new position. The proxim al catheter/reservoir and valve can subsequently be sutured to the tubing.
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III Nontraum atic Em ergencies
364
Figure
Procedural Steps
Pearls
Fig. 21.15
After CSF ow is observed, the distal catheter is inserted into the peritoneal cavity w ith tw o smooth forceps (Adson or bayonet). The peritoneum is closed w ith absorbable suture maintaining the shunt tubing in the peritoneum and aw ay from the suture loops.
• The catheter should sm oothly slide into the peritoneum . If it form s a tight coil or is ejected, it is possible to be preperitoneal or trapped in adhesions.
21
Ventricular Shunt Malfunction
Placement: Ventricular Catheter and Tunneling for External Drainage (Fig. 21.16)
Figure
Procedural Steps
Pearls
Fig. 21.16
If circumstances require removal of an entire shunt system w ith continued need for ventricular drainage, then an external drain is placed. Placement of antibiotic-impregnated ventricular catheter9 occurs w ith ideal placement of the tip anterior to the ipsilateral foramen Monro. We typically utilize stereotactic navigation or alternatively use anatomic landmarks.
• Prevent CSF from leaking to improve likelihood of cannulating the ventricle.
The distal end of the tubing is then tunneled subcutaneously utilizing a trocar to an exit site at least 5 cm from the edge of incision. The exiting tubing is securely xed w ith a purse string stitch to prevent CSF leak and connected to sterile external CSF collection bag (inset).
Closing • After appropriate irrigat ion w oun ds are closed in a m ult ilay-
• Th e abdom in al w oun d is also closed in a layered fash ion :
ered fash ion . We u se absorbable braided su t u re su t u res for su bcu t an eou s an d absorbable m on o lam en t su t u res for skin closure. Cu rren t sut ures are an t ibiot ic im pregn ated. If th e w ou n d is of qu est ion able in tegrit y, w e u t ilize nylon su t ures for closure.
t ran sversalis fascia, an terior an d posterior rect u s sh eath s, Scarpa’s fascia, an d th e skin . Met icu lou s at ten t ion is paid th rough ou t th e closing to m atch up th e an atom ic layers an d avoid kin king or injuring th e sh u n t t ubing. Glue is placed on th e skin surface after su bcut icu lar closure.
•
•
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Externalizing the Distal Catheter (Fig. 21.17)
a
b
366
Figure
Procedural Steps
Pearls
Fig. 21.17
(a) A small incision (1 cm) is marked at a level near the clavicle and made w ith a no. 10 blade through the epidermis. Use monopolar cautery to dissect dow n to the subcutaneous fat. Use blunt dissection w ith small hemostat to nd the catheter. Typically, a connective tissue sheath may need to be incised w ith cautery to isolate the tubing. (b) The distal part of the tubing is then externalized through the clavicular incision.
• One m ay use ultrasound to assist with tube localization if it is not easily palpable. In cases of pseudocyst the distal tubing m ay be used to drain the cyst, and the cyst uid should be sent for stat Gram stain and culture. Propionibacterium is a com m on cause of pseudocyst but may take 2 weeks for a positive culture to grow.
21
Ventricular Shunt Malfunction
Wound Closure (Fig. 21.18)
Figure
Procedural Steps
Pearls
Fig. 21.18
A nylon purse string suture is used at tubing exit site and the catheter is connected to a sterile, external CSF collection bag (inset).
• Make sure that purse string suture is not to tight and allows CSF passage.
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III Nontraum atic Em ergencies
Fig. 21.19 Postoperative CT scan of same patient depicted in Fig. 21.2 after shunt revision.
Postoperative Management Pract ice pat tern s var y: w e rout in ely obt ain an im m ediate postoperat ive CT if th e ven t ricu lar cath eter is revised. Th e im m ediate postop CT ser ves as a baselin e for th e follow up (Fig. 21.19). A sh u n t series con sist ing of p lain radiograph s is reason able after m ost p rocedu res to en su re proper p lacem en t of sh un t an d as a baselin e assessm en t for com p arison in follow -u p sh ou ld problem s arise. Th e usual length of st ay in th e h ospital is 24–72 h ou rs dep en ding on com p lexit y of th e case an d clin ical con dit ion of th e pat ien t . Typical follow -up occu rs at 2 w eeks for a w oun d ch eckup th en at 6 w eeks w ith repeat im aging, t ypically a rapid sequ en ce MRI.
Special Considerations In pediat ric pat ien t s w e t yp ically follow -u p at yearly in tervals w ith or w ith ou t im aging, dep en d ing on sym ptom s. If th e pat ien t is w ell, n o im aging m ay be n eeded except at sur veillan ce scan in ter vals of 1–5 years. We obtain a sh u n t series to en su re n o cath eter discon n ect ion s are seen an d to follow th e length of th e distal cath eter after th e last sh u n t in sert ion . If th e pat ien t goes th rough a rapid grow th period or if th ere is any
368
sw elling in th e sh u n t t rack, an oth er su r veillan ce sh u n t series m ay be ap p rop riate. Program m able sh u n ts n eed to be reprogram m ed an d th e valve set t ing con rm ed follow ing exp osu re to th e h igh m agn et ic eld of an MRI.
References 1. Brow d SR, Ragel BT, Got tfried ON, et al. Failu re of cerebrosp in al uid sh un t s: part I: Obst ruct ion an d m ech an ical failure. Pediat r Neurol 2006:34;83–92 2. Brow d SR, Got tfried ON, Ragel BT, et al. Failu re of cerebrosp in al uid sh un t s: part II: overdrain age, loculat ion , an d abdom in al com plicat ion s. Pediat r Neurol 2006:34;171–176 3. Barn es NP, Jon es SJ, Hayw ard RD, et al. Ven t ricu lop eriton eal sh un t block: w h at are th e best predict ive clin ical in dicators? Arch Dis Ch ild 2002:87;198–201 4. O’Neill BR, Pru th i S, Bain s H, et al. Rap id sequ en ce m agn et ic reson an ce im aging in th e assessm en t of ch ildren w ith hydroceph alus. World Neurosurg 2013;80(6):e307–312 5. Pitet t i R Em ergen cy dep ar t m en t evalu at ion of ven t ricu lar sh u n t m alfun ct ion: is th e sh un t series really n ecessar y? Pediat r Em erg Care 2007:23;137–141 6. Kestle JR, Garton HJ, W hitehead W E, et al. Managem ent of shunt infections: a m ulticenter pilot study. J Neurosurg 2006:105;177–181
21 7. Kestle JR, Riva- Cam brin J, Wellon s JC, 3rd , et al. A st an dard ized protocol to reduce cerebrospin al uid shu nt in fect ion : th e Hydroceph alu s Clinical Research Net w ork Qu alit y Im provem en t In it iat ive. J Neu rosu rg Pediat r 2011:8;22–29 8. Stein bok P, Coch ran e DD Rem oval of ad h eren t ven t ricu lar cath eter. Ped iat r Neu rosu rg 1992:18;167–168 9. Parke r SL, An d e rson W N, Lilie n feld S, et al. Ce reb rosp in al sh u n t in fe ct ion in p at ie n t s re ce ivin g an t ibiot ic- im p regn at ed ve rsu s st an d ard sh u n t s. J Ne u rosu rg Pe d iat r 2011:8; 259–265
Ventricular Shunt Malfunction
10. Hayh urst C, Beem s T, Jen kin son MD, et al. E ect of elect rom agn et ic-n avigated sh un t placem en t on failure rates: a prospect ive m u lt icen ter st udy. J Neurosu rg 2010:113;1273–1278 11. Tubbs RS, Maher CO, Young RL, et al. Dist al revision of ven t riculoperiton eal sh un t s using a peel-aw ay sh eath . J Neurosurg Pediat r 2009:4;402–405 12. Naftel RP, Argo JL, Sh ann on CN, et al. Laparoscopic versus open in sert ion of th e periton eal cath eter in ven t riculoperiton eal sh un t placem ent: review of 810 consecut ive cases. J Neurosurg 2011:115;151–158
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22
Pituitary Apoplexy Kalm on D. Post and Soriaya Mot ivala
Introduction Pit uit ar y apoplexy is a n eu rosurgical em ergency in w h ich p rom pt in ter ven t ion m ay h alt an d even reverse associated n eu rologic de cit s an d possible m or talit y. Th e con dit ion results from h em orrh age or n ecrosis of a pit u it ar y t u m or. It h as been fou n d to occu r in 0.6 to 10.5% of all p it u itar y aden om as.1 In 1950, Brough am w as th e rst to describe th e clin ical an d p ath ologic n dings of ve p at ien t s w h o presen ted w ith ch anges in m en tal st at u s, h eadach es, m en ingism u s, an d ocu lar dist u rban ces.2 Sin ce th en , th ere h as been exten sive in terest in th e en t it y as w ell as con siderable debate on w h at th e term pit uitary apoplexy en com p asses. In fact , th ere h ave been rep or t s of silen t pit uit ar y apoplexy.3 Moh r est im ated th e in ciden ce of asym ptom at ic h em orrh ages in pit u it ar y aden om as to be 9.9% as opposed to 0.6% th at presen ted w ith clin ical n dings.4 Furth erm ore, On est i described ve pat ien ts w ith subclin ical p it u it ar y ap oplexy, th at is, a clin ically silen t yet exten sive h em orrh age in to a pit u it ar y aden om a.5 With su ch a broad in terp retat ion in th e literat u re it is in creasingly h elpfu l to de n e th e diagn osis of pit uitar y apoplexy by clin ical param eters th at in clude th e sudden on set of h eadache, m en ingism u s, visu al im p airm en t , an d occu lom otor abn orm alit ies in var ying com bin at ion s along w ith radiologic eviden ce of h em orrh age in or su dden exp an sion of a pit u it ar y aden om a.
• Th e m ost im port an t en t it y th at m ust be con sidered an d • • • •
Preprocedure Considerations Radiographic Imaging • CT w ith ou t con t rast is m ost valu able th e •
Indications • Diagn osis of ap oplexy requ ires evid en ce of h em orrh age or
•
•
370
rap id exp an sion on eith er com p u ted tom ography (CT) or m agn et ic reson an ce im aging (MRI) w ith in a preexist ing aden om a as w ell as clin ical correlat ion . Pat ien t s often p resen t w ith su dden on set of h eadach e, m en ingism u s, dist u rban ces of m en t al st at u s, an d ocu lar n dings th at can range from ophth alm oplegia an d visual eld defect s to m on ocu lar or bin ocular blin dn ess. Bacterial an d viral m en ingit is, in t racerebral h em atom a, opt ic n eu rit is, brain stem in farct ion , tem p oral arterit is, en cep h alit is, t ran sten torial h ern iat ion , cavern ou s sin us th rom bosis, an d m igrain e m ay all in on e form or an oth er m im ic an acu te p it u it ar y vascu lar acciden t .1,6
exclu ded is an an eu r ysm al su barach n oid h em orrh age.7,8 A rupt ured Rath ke’s cleft cyst , th ough rare, m ay also m im ic p it u it ar y apoplexy.9,10 In it ial m edical st abilizat ion w ith in t raven ou s u id an d steroids is requ ired in all cases to correct th e profou n d hypoadren alism th at m ay result . Tran ssph en oidal resect ion is con sidered for th ose w ith con t in ued n eurologic de cit after in it ial con ser vat ive therapy, an d im m ed iately for th ose w ith loss of acu it y an d/or eld s.6 W h ile oph th alm oplegia h as been sh ow n to correct as frequ en tly w ith con ser vat ive m an agem en t as w ith surgical in ter ven t ion ,11–13 su rgical resect ion o ers th e m ost h ope of im proving visual eld an d acuit y de cits. Many st udies h ave suggested th at decom p ression w ith in 1 w eek m ay o er th e best ch an ce of visual recover y.11,14 Oth ers h ave sh ow n im provem en t w ith decom pression m on th s after in it ial visu al loss.15
• •
rst 2 days of
h em orrh age (Fig. 22.1). After 48 h ours, MRI is m ore sen sit ive, as it can bet ter delin eate older blood from t um or an d areas of n ecrosis from cyst ic ch anges (Fig. 22.2). Th e MRI is also h elpful in est im ating th e age an d t im e course of th e h em orrh age. Hem orrh ages less th an 7 days w ill appear hypo- to isoin ten se on T1- an d T2-w eigh ted im ages. During th e secon d w eek a hyperin ten se sign al can be fou n d bordering th e h em atom a. By th e secon d w eek in creasing hyp erin ten sit y w ill be seen th rough ou t th e h em atom a on both T1- an d T2-w eigh ted im ages. If clin ically w arran ted, an angiogram or m agn et ic reson an ce angiogram (MRA) sh ou ld be obtain ed if n eith er CT n or MRI is able to ru le ou t a con com it an t an eu r ysm . MRI w ill also best dem on st rate th e exten sion of th e t u m or or h em orrh age in to th e suprasellar space as w ell as ch iasm al com pression an d cavern ous sin us exten sion . Fur th erm ore, th e in t racarot id dist an ce can be delin eated in order to avoid injur y during surgical resect ion .
22
Pituit ary Apoplexy
a
c
b
Fig. 22.1a–c (a) Axial and (b, c) coronal CT scans showing hemorrhagic cavit y with uid- uid level and surrounding enhancing sellar lesion.
a
b Fig. 22.2a, b (a) T1-weighted sagit tal and (b) coronal MRI demonstrating a sellar m ass of heterogeneous signal intensit y, with suprasellar extension of increased signal intensit y consistent with acute hemorrhage.
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Medication
Operative Field Preparation
• It is ou r p ract ice to give d exam eth ason e 16 m g/day p rior
• After in t ubat ion th e pat ien t’s eyelids are gen tly t aped sh ut
to su rger y an d to tap er to a sligh tly su p rap hysiologic level postoperat ively. Fu rtherm ore, it is ou r pract ice to sen d a full en docrin e pan el at th is t im e as a baselin e. Th irt y m in utes prior to in it ial in cision , 1.5 g of cefuroxim e is given (if th e pat ien t h as n o rep or ted allergies to p en icillin ; oth er w ise, van com ycin an d gen t am icin are p referred). An t ibiot ics are con t in u ed postop erat ively w h ile th e n asal packings are in place.
an d bet adin e is ap p lied over th e n ares, ch eeks, an d u p per lip . Betadin e-dip ped sw abs are used to clean th e in side of both n ost rils as w ell as u n d er th e u p p er lip (for possible su blabial ap p roach sh ou ld it becom e requ ired). Th e righ t abdom en is prepped sterilely w ith a separate t ray of bet adin e for possible fat graft . Flu oroscopy or im age-gu ided n avigat ion are em p loyed th rough out th e case to determ in e appropriate t rajector y in a m idlin e p lan e.
• •
372
• • •
22
Pituit ary Apoplexy
Operative Procedure Microscopic Pituitary Tumor Resection Positioning and Fluoroscopy (Fig. 22.3a, b) a
b
Figure
Procedural Steps
Pearls
Fig. 22.3
Patient is placed on far right edge of table in supine position. Right arm is bent 90 degrees and secured across chest w ith padding and tape.
• Patient is positioned to allow for ease •
(a) Head is placed on a foam “holder” w ith right ear tilted 45 degrees in relation to right shoulder. Head of bed is exed just slightly such that the chest does not interfere w ith use of instruments.
of trajectory to the sella. If used, im age guidance system s should be set up to allow ease of viewing while surgeon is in operative position.
(b) Fluoroscopy is positioned at the head of the bed to obtain lateral view of the sella.
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Fluoroscopy Imaging (Fig. 22.4)
374
Figure
Procedural Steps
Fig. 22.4
Initial lateral skull uoroscopic images are obtained to evaluate trajectory to the sella.
22
Pituit ary Apoplexy
Draping and Operating Microscope (Fig. 22.5a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 22.5
(a) Surgical elds of the nasal passages and the right low er abdominal quadrant are prepped and draped in a sterile fashion. (b) The operating microscope is sterilely draped and positioned for optimal view through the right nasal passage.
• Abdom inal fat graft m ay becom e required •
if cerebrospinal uid is encountered during resection (see Fig 22.12). When operating through the right nostril, the observer is positioned to the left.
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Mucosal Flap (Fig. 22.6a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 22.6
(a) Using a handheld speculum as w ell as uoroscopy/image guidance to direct the dissection tow ard the sella, the nasal mucosa is identi ed in the midline and 1–2 mL of lidocaine w ith epinephrine 1:100,000 are injected betw een the mucosa and bony nasal septum. This causes the mucosa to blanche and separate from the septum.
• Trajectory to the sella
(b) A no. 15 blade is then used to make a linear incision in the mucosa and the mucosa is dissected o the septum using a Freer instrument.
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usually follows the m iddle turbinate.
22
Pituit ary Apoplexy
Identi cation of the Sphenoid Bone (Fig. 22.7a, b)
a
b
Figure
Procedural Steps
Fig. 22.7a, b
(a) The septum is the deviated to the patient’s left and the keel-shaped vomer of the sphenoid is exposed. (b) A hands free speculum is then placed w ith one blade on either side of the vomer.
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Exposure of the Sella (Fig. 22.8a–c)
a
b
378
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Pituit ary Apoplexy
c
Figure
Procedural Steps
Pearls
Fig. 22.8
(a) A combination of rongeurs and pituitary instruments are used to remove the vomer, enlarging the bilateral ostia into the sphenoid sinus. The sphenoid sinus mucosa is moved aside.
• The rem oved bone is saved for later use
(b) A small osteotome and mallet is used to fracture the sella oor, and then Kerrison rongeurs are used to remove it. (c) Lateral uoroscopy image depicting the trajectory of the speculum w ith instruments marking the superior and inferior limits of the sella turcica.
• •
at closure. It is im portant to note that sphenoid sinus septations are not usually m idline; the vom er marks the m idline. Fluoroscopy or im age guidance allows the surgeon to be certain of being m idline at this juncture.
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Dural Incision and Pituitary Tumor Resection (Fig. 22.9)
380
Figure
Procedural Steps
Pearls
Fig. 22.9
The dura, now exposed, is then incised using a no. 15 blade in a cruciate fashion. Ring curettes of various sizes are then used to remove the infarcted hemorrhagic tumor in a stepw ise fashion inferiorly then laterally to the limits of the cavernous sinus and nally superiorly.
• Resection in the superior plane is left until the end to avoid the descent of arachnoid into the operative eld, m aking further resection di cult.
22
Pituit ary Apoplexy
Reconstruction of the Sella Floor (Fig. 22.10)
Figure
Procedural Steps
Pearls
Fig. 22.10
After irrigation the previously removed bone fragments are placed to reconstruct the sellar oor.
• If CSF is seen, a piece of subcutaneous fat harvested from the abdom en is packed in the sella and sphenoid sinus (see Fig. 22.12 for graft harvesting).
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Hemostasis and Closure (Fig. 22.11)
382
Figure
Procedural Steps
Pearls
Fig. 22.11
Hemostasis is secured and the retractor is removed. Using a handheld speculum, a nasal tampon is placed in the right nares to ensure that the mucosal ap is ush w ith the nasal septum.
• Right-sided nasal packing is alm ost always placed; however, left nasal packing is placed only if CSF was seen or if bleeding was appreciated.
22
Pituit ary Apoplexy
Abdominal Fat Graft (Fig. 22.12)
Figure
Procedural Steps
Pearls
Fig. 22.12
If necessary an abdominal fat graft is harvested by making a small linear incision in the right low er quadrant and removing a quarter-sized piece of subcutaneous fat. The incision is then closed w ith 3-0 inverted absorbable braided sutures and subcuticular absorbable mono lament closure.
• It is im portant not to contam inate the abdom en with any instruments that have been placed in the nose.
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Postoperative Management • Dexam eth ason e or hydrocort ison e is con t in u ed in th e im m e• •
• • •
diate postoperat ive period. If a left sid ed packing w as placed it is rem oved th at even ing. Th e pat ien t is m on itored for any sign s of addison ian crisis as w ell as diabetes in sipidu s. To th at en d st rict m easu rem en t s of in t ake an d ou t p u t are t aken as w ell as daily sodiu m an d osm olalit y levels. Sh ou ld th e p at ien t h ave m ore th an 200 m L/h r of urin e out put over th e course of 3 con secut ive h ou rs repeat sodium level is draw n an d if it is elevated, desm op ressin acetate th erapy is in it iated. Postop erat ive day 2 th e righ t p acking is rem oved an d th e pat ien t is disch arged if th ey con t in ue to be st able. En docrin e labs are sen t as out pat ien t to assess th e level of pit uit ar y fun ct ion . Neu rosu rgical, en docrin e, an d op h th alm ology follow -u p is provided.
Special Considerations • It is ou r preferen ce to u se th e operat ing m icroscop e for th e
•
t ran ssph en oidal approach ; h ow ever, t ran ssph en oidal en doscopy is also often u sed to provide w ider exposure. Surgeon com for t level sh ould dict ate w h ich tech n ique is u sed. Cran iotom y is reser ved for pat ien ts w ith a n on aerated sph en oid sin u s, a sm all sella w ith a large su prasellar m ass, a t igh t diaph ragm a sellae w ith a dum bbell-sh aped m ass, or an associated in t racerebral h em atom a.5,16
References 1. Naw ar RN, AbelMan n an D, Selm an W R, Arafan BM. Pit u it ar y t um or apoplexy: a review. J In ten sive Care Med 2008:23(2): 75–90
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2. Brough am M, Heu sn er AP, Adam s RD. Acu te degen erat ive ch anges in aden om as of th e pit u it ar y body—w ith special referen ce to pit uit ar y apoplexy. J Neurosurg 1950:7(5):421–439 3. Fin dling JW, Tyrrell JB, Aron DC, Fit zgerald PA, Wilson CB, Forsh am PH. Silen t p it u it ar y apop lexy: su bclin ical in farct ion of an adren ocor t icot ropin -produ cing pit uit ar y aden om a. J Clin En docrin ol Met ab 1981;52(1):95–97 4. Moh r G, Hardy J. Hem orrh age, n ecrosis, an d apop lexy in p it u it ar y aden om as. Surg Neurol 1982;18(3):181–189 5. On est i ST, Wisn iew ski T, Post KD. Clin ical versu s su bclin ical p it uit ar y apoplexy: presen t at ion , surgical m an agem ent , an d outcom e in 21 pat ien t s. Neurosurger y 1990;26(6):980–986 6. Mu rad-Kejbou S, Eggen berger E. Pit u it ar y ap oplexy: evaluat ion , m an agem en t , an d p rogn osis. Cu rr Op in Op h th alm ol 2009;20(6):456–461 7. Su zu ki H, Mu ram at su M, Mu rao K, Kaw agu ch i K, Sh im izu T. Pit u it ar y ap op lexy cau sed by ru pt u red in tern al carot id ar ter y an eu r ysm . St roke 2001;32(2):567–569 8. Okaw ara M, Yam agu ch i H, Hayash i S, Mat su m oto Y, In ou e Y, Okaw ara S. [A case of r u pt u red in tern al carot id ar ter y an eu r ysm m im icking pit uit ar y apoplexy]. No Shin kei Geka 2007;35(12): 1169–1174 9. On est i ST, Wisn iew ski T, Post KD. Pit u it ar y h em orrh age in to a Rath ke’s cleft cyst . Neurosurger y 1990;27(4):644–646 10. Ch aiban JT, et al. Rath ke cleft cyst ap op lexy: a n ew ly ch aracterized dist in ct clin ical en t it y. J Neurosurg 2011;114(2):318–324 11. Ran deva HS, Sch oebel J, Byrn e J, Esiri M, Adam s CB, Wass JA. Classical pit uit ar y apoplexy: clin ical feat u res, m an agem ent an d outcom e. Clin En docrinol (Oxf) 1999;51(2):181–188 12. Maccagn an P, Macedo CL, Kayath MJ, Noqu eira RG, Abu ch am J. Con ser vat ive m an agem en t of pit u it ar y ap oplexy: a p rosp ect ive st u dy. J Clin En docrin ol Met ab 1995;80(7):2190–2197 13. Nishioka H, Haraoka J, Miki T. Spontaneous rem ission of functioning pituitar y adenom as w ithout hypopituitarism follow ing infarctive apoplexy: t wo case reports. Endocr J 2005;52(1):117–123 14. Mu th u ku m ar N, Rosset te D, Sou daram M, Sen th ilbabu S, Badrin arayan an T. Blindn ess follow ing pit u it ar y apoplexy: t im ing of surger y an d n euro-oph th alm ic outcom e. J Clin Neurosci 2008;15(8):873–879 15. Paren t AD. Visu al recover y after blin d n ess from pit u it ar y apoplexy. Can J Neurol Sci 1990;17(1):88–91 16. Cardoso ER, Peterson EW. Pit u it ar y ap op lexy: a review. Neu rosurger y 1984;14(3):363–373
IV
Emergency Operations in Combat
23
Combat Cranial Operations Leon E. Moores
Introduction This chapter covers the procedure for a large hem icraniectom y follow ing severe penetrating com bat traum a w ith m assive soft tissue involvem ent. Sim ilar operative principles apply for less severe penetrating w ounds, as well as for hem icraniectom y for blunt traum a. W here blunt traum a is concerned, the m ost signi cant divergence involves preoperative decision m aking. We have tended throughout recent con ict to be quite aggressive w ith surgical intervention for both blunt and penetrating traum a. Longterm outcom e studies are pending, but initial experience justi es continuing this aggressive approach in our patient population.1,2 Com parisons bet w een civilian and com bat cranial traum a m ay be di cult because of the service m em bers’ very young average age and high overall level of tness, the nearly im m ediate availabilit y of basic and advanced life support care, and extraordinarily robust resources on the bat tle eld and w ithin close proxim it y of w ounding. Additionally, com bat injuries are n otable for m assive soft tissue/bone/brain injury, gross contam ination (often w ith aggressive organism s), concurrent injuries to face/neck/extrem ities/trunk, and extended patient transfers. Evacuation to facilities in Germ any and, then, onward to national m ilitary m edical centers in Beth esda, Marylan d, con sists of t w o ights of m ore than 6 hours duration w ithout in- ight neurosurgical capabilit y.3 How ever, th e m ajor goals of su rger y in both sit u at ion s are rem oval of con tam in an ts (in clud ing devit alized t issue), brain stem decom pression , h em ost asis, sku ll base recon st ru ct ion (w ith obliterat ion of air- lled sin u ses), dural coverage, soft t issue coverage, an d stabilizat ion for t ran sp or t w ith app rop riate m on itoring in p lace an d fu n ct ion ing.
Indications
• In t h e com bat set t in g, low GCS score (, 5) is n ot n ecessarily a con t rain d icat ion to su rgical in ter ven t ion . Ad d it ion ally, p u p illar y asym m et r y or d ilat ion m ay be t h e resu lt of t rau m at ic ir id op legia or ch em ical ir r it at ion . Th e overall clin ical p ict u re an d w ou n d ing h istor y m u st be t aken in to accou n t before m akin g a d ecision to categor ize a p at ien t as exp ect an t . Becau se of t h e d i eren ces in p at ien t p op u lat ion as ou t lin ed , t h is in d icat ion m ay n ot fu lly t ran slate in to civilian p ract ice.
Preprocedure Considerations Consultation/Teamw ork Su ccessfu l m an agem en t of p at ien t s severely w ou n d ed in com bat operat ion s is t ruly a m ult idisciplin ar y e ort . Mult iple surgical sp ecialist s are often involved—in addit ion to e or ts from an esth esiology, n u rsing, an d laborator y/blood ban k. A single p at ien t m ay presen t w ith an ext rem it y am p ut at ion , an abd om in al pen et rat ion , exposed brain , a p ar t ially en ucleated globe, an d severe soft t issu e/bon e loss involving th e m axilla, requ iring sim u ltan eou s evalu at ion an d su rgical m an agem en t by ve sp ecialists. Con st an t com m un icat ion an d coordin at ion is required am ong all m em bers of th e team .
Radiographic Imaging • Com puted tom ography (CT) scan is rou t in ely available at th e •
• Severe p en et rat ing t rau m a. • Blu n t t rau m a w ith sign i can t m ass e ect from h em isp h eric •
386
sw elling or h em atom a. Absen ce of m ajor disrupt ion of m idline deep cerebral n uclei in th e region of th e sella (zon a fat alis). Disrupt ion of th e zon a fatalis—t yp ically associated w ith Glasgow Com a Scale (GCS) 3— is a relat ive con t rain dicat ion to operat ive in ter ven t ion .4
•
m edical facilit ies in th eater w h ere n eu rosu rgical capabilit y is presen t . Angiography is n ot rout in ely available an d requires th e presen ce of both specialized equ ipm en t an d a t rain ed n eu roin ter ven t ion alist . W h ere angiograph ic capabilit y is available in th eater, it h as proven u seful in th e m an agem en t of pen et rating t raum a of th e n eck an d h ead. Upon arrival to th e Un ited St ates, angiography is often perform ed—w h eth er blu n t or p en et rat ing m ech an ism —due to th e in creased in ciden ce of vasosp asm associated w ith blast-related t rau m a, even in th e absen ce of cran ial pen et rat ion .5 Preoperat ive im aging (Fig. 23.1a, b).
23
Com bat Cranial Operations
a
b Fig. 23.1a, b CT (a) brain and (b) bone images of a frontotemporoparietal IED injury demonstrating t ypical massive soft tissue swelling, air- lled sinus disruption, intracranial fragments, and epidural hematoma. These are actual hardcopy images from in-theater CT scan operating under extreme weather and force protection conditions. Digital records are not available for higher resolution.
Medication
Operative Field Preparation
• Recen tly p u blish ed guidelin es for p en et rat ing brain injur y
• Vigorous clean sing of con tam in ated adjacen t soft t issue
recom m en d an t ibiot ic prophyla xis w ith cefazolin . Prophyla xis t yp ically is con t in u ed u n t il 24 h ours follow ing rem oval of extern al ven t ricular device (EVD) or in t racran ial pressu re (ICP) m on itor, or a total of 48 h ours if n o such devices are p resen t . Con siderat ion m ay be given to exten ded coverage w ith gen t am icin an d pen icillin if gross con t am in at ion is p resen t . Pat ien t s w h o are allergic to p en icillin m ay be t reated w ith van com ycin an d cipro oxacin .6 Seizu re p rop hylaxis w ith dip h enylhydan toin is in it iated preoperat ively.
is com pleted w ith irrigat ion , soap an d w ater, alcoh ol, an d p ovidon e iodin e or ch lorh exidin e. Exposed brain t issu e is irrigated w ith salin e on ly. Con t rar y to stan dard p ract ice in th e elect ive set t ing, th e h air is clipped w idely both to rem ove gross con t am in at ion an d to allow bet ter visu alizat ion of addit ion al areas of pen et rat ion . Th e in cision s are m arked an d in lt rated w ith 1% lidocain e w ith epin eph rin e 1:100,000.
•
•
387
IV Em ergency Operations in Com bat
Operative Procedure Positioning and Preparation (Fig. 23.2)
Figure
Procedural Steps
Pearls
Fig. 23.2
Removal of debris is recommended prior to nal prep. If a fragment is rmly embedded or adjacent to vascular structures the fragment is prepped into the eld.
• Alcohol, iodine, and other noxious prep
The head is turned in a manner that optimizes visualization of the most severely injured area. Typically, the most devastated portion of the w ound is placed at the highest point in the operative eld, angled slightly tow ard the surgeon for best visualization and operative control of any deep injuries along the w ound tract. Copious normal saline irrigation is used on any exposed brain tissue. If there is su cient uninjured space on the lateral thigh, it is prepped for a potential fascia lata graft.
388
agents are not applied to exposed brain.
23
Com bat Cranial Operations
Urgent Hemostasis (Fig. 23.3)
Figure
Procedural Steps
Pearls
Fig. 23.3
Hemostasis w ithin the brain parenchyma must be achieved rapidly in the case of severe penetrating trauma. Signi cant intracranial sources of bleeding often preclude w orking slow ly from “super cial to deep.” Continuous arterial bleeding from intracranial sources is commonly encountered upon removal of eld dressings and use of saline irrigation. Hemostasis must be achieved before attending to non-lifesaving interventions such as soft tissue debridement.
• Often, excellent hem ostasis of low-volum e bleeding zones within a m assive area of injury can be achieved by allowing the topical hem ostatic agents to rem ain in place—if one can resist the temptation to rem ove them .
All methods of hemostasis must be considered. The best method is often “time.” When encountering multiple areas of signi cant active hemorrhage, the surgeon must pack o the least w orrisome w ith gelatin sponge, strips of hemostatic oxidized cellulose polymer, cotton patties, etc. and gain control of the most vigorous bleeding points.
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IV Em ergency Operations in Com bat
Soft Tissue Debridement (Fig. 23.4)
390
Figure
Procedural Steps
Pearls
Fig. 23.4
Soft tissue debridement is accomplished w ith a combination of sharp and blunt dissection. Devitalized and grossly contaminated soft tissue is removed. It is important to keep in mind the requirement for soft tissue coverage of the nal construct and to minimize the excision of soft tissue w hich is not clearly devitalized. A signi cant portion of the muscle and skin may be severely contused, yet quite viable, and should be salvaged.
• Even with wounds such as in Fig. 23.2, the elasticit y of the scalp is such that prim ary closure is the norm . Aggressive undermining of the scalp (which aids in pericranial graft harvest) also helps to achieve prim ary coverage if a signi cant portion of the scalp has been devitalized.
23
Com bat Cranial Operations
Bony Debridement (Fig. 23.5)
Figure
Procedural Steps
Pearls
Fig. 23.5
Aggressive debridement of super cial bone fragments is indicated. The availability of excellent modern modeling techniques for calvarial reconstruction precludes the need to preserve complex, three -dimensional bony structures w here comminution is present. 7
• Particularly in the case of contaminated wounds, the absence of blood supply to bone fragm ents m ay increase infection risk.
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IV Em ergency Operations in Com bat
Scalp Incision (Fig. 23.6a, b)
a
b
C
Figure
Procedural Steps
Pearls
Fig. 23.6
(a) An extended reverse question mark incision allow s for a generous hemicraniectomy and provides excellent access to harvest a large, vascularized pericranial graft—essential to the reconstruction of often massive skull base and aerated sinus defects.
• (b) Extension of the lateral incision
(c) In some cases, the very large scalp ap described above may be vulnerable to posterior scalp breakdow n. The surgeon may consider a midline incision and ipsilateral extension of Kempe, as revisited by Martin, 1 taking advantage of the angiosomes of the occipital artery to improve results w ith cosmetic reconstruction. 8
392
•
anterior to the tragus and the m idline incision behind the contralateral hairline, if necessary, can provide excellent exposure of the frontal fossa and zygom a. While this incision forfeits the advantage of a vascularized pericranial pedicle, free grafts m ay be harvested from the posterior scalp.
23
Com bat Cranial Operations
Hemicraniectomy (Fig. 23.7)
Figure
Procedural Steps
Pearls
Fig. 23.7
The ideal bony incision is just lateral to the superior sagittal sinus, just above the transverse sinus, and along the temporal and frontal fossa oors.
• Over the course of the recent con ict, we have becom e advocates of very large, nearly hem ispheric bone aps—in part, due to an inabilit y to provide emergency neurosurgical intervention during a lengthy transport. On occasion, if m inim al dam age to the brain is accompanied by signi cant loss of brain tissue and very lit tle postoperative swelling is anticipated, prim ary reconstruction of the bony injury can be accomplished acutely. Primary reconstruction should be considered for relatively super cial wounds, even with severe fragm entation of bone and disruption of soft tissue. Frontal injuries, where the potential for brainstem compression is less of a concern, are often good candidates. The abilit y to m onitor ICP becom es m ore important in this set ting.
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IV Em ergency Operations in Com bat
Brain Debridement (Fig. 23.8)
394
Figure
Procedural Steps
Fig. 23.8
Brain debridement is performed using normal saline bulb irrigation to w ash aw ay large fragments of obviously devitalized brain tissue. Hemostasis is attained, further irrigation is applied, and gross areas of contamination are removed. Gentle exploration of w ound tracts is appropriate in order to remove obvious and easily accessible contaminants, but deeply embedded fragments are not removed unless indicated by later angiography or a subsequent infection.
23
Com bat Cranial Operations
Skull Base Reconstruction, Pericranial Graft (Fig. 23.9)
Figure
Procedural Steps
Fig. 23.9
Dural coverage is obtained using primary dural tissue w hen available. Fascia lata is harvested if su cient dura is not available. Dural substitutes are available in theater if neither can be used. Reconstruction of the skull base is done w ith local bone, if available ; otherw ise, harvested bone is employed for this purpose. In the rare circumstance that neither is available, arti cial materials such as titanium can be used over small areas as long as pericranial coverage is used. It is important to ensure obliteration of any involved air- lled sinuses. This is done by w idely opening the sinus, removing mucosa, and packing the sinus fully w ith muscle and/or fat. Extensive pericranial graft tissue, w ith a vascularized pedicle, can be harvested due to the expansive scalp exposure (see Fig. 23.6). The graft can be maneuvered into place to cover an exenterated air- lled sinus (or skull base reconstruction) and sew n over the packed sinus cavity to the adjacent dura. When possible, anchor the temporalis muscle to scalp or bone in order to preserve its normal anatomic position and allow for later optimal cosmetic reconstruction.
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IV Em ergency Operations in Com bat
Closing
• Sedat ion , p ain con t rol m easu res, an d ven t ricu lar drain age to con t rol ICP are closely m on itored an d m an aged by on board in ten sivists an d crit ical care n ursing st a .
Cranial Incision • Th e in t racran ial space an d w oun d cavit y are irrigated w ith •
•
copious am oun ts of salin e. Th e surgical site is reassessed for h em ostasis. An ICP m onitoring device is placed prior to closure. Ventriculostom y is preferred, since it is both diagnostic and therapeutic. Care m ust be taken to properly allow for pressure relief w hen the patient is taken high altitudes for intercontinental transport. Th e tem poralis an d su bcut an eous t issue are reapproxim ated w ith absorbable 0 or 2-0 sut ure. Th e scalp t ypically is closed w ith staples.
Medication • An t iepilept ic prophylaxis is con t in u ed for 7 days. • Prophylact ic an t ibiot ics are con t in ued for 48–72 h ours.
Radiographic Imaging • Repeat CT im aging is t ypically obt ain ed postoperat ively, th e
Low er Extremity Incision • After cop iou s an t ibiot ic irrigat ion , th e fascia lat a h ar vest ing
•
site is closed w ith a deep layer of 2-0 absorbable su t u re, follow ed by skin staples.
Postoperative Management Monitoring
•
n ext m orn ing, an d on an as-n eed ed basis th ereafter for n eu rologic ch anges. Im aging requirem en t s are balan ced again st h em odyn am ic st abilit y an d oth er risks of t ran sport to im aging suite. We h ave becom e m uch m ore aggressive w ith angiography due to in creased in ciden ce of vasospasm , pseudoan eur ysm , an d delayed h em orrh age in pat ien t s exp osed to blast en ergy. In addit ion to in ciden ces of obviou s vascu lar inju r y, w e rou t in ely perform angiogram s in th e follow ing pat ien t s to look for occu lt inju r y: p en et rat ing inju r y n ear th e circle of Willis, Sylvian ssure, or posterior fossa; kn ow n vasospasm ; an d blast-associated blun t t raum a. Postop erat ive im aging (Fig. 23.10a, b).
• If placed in th eater, invasive ICP m on itoring devices are retain ed th rough out t ran spor t to Germ any an d th e con t in en tal Un ited St ates. Fig. 23.10a, b CT (a) brain and (b) bone windows obtained in the postoperative period.
a
b
396
23
Special Considerations • We h ave n oted postoperat ive ch allenges w ith vasospasm , •
p seu doan eu r ysm form at ion , ver y low pressu re hydroceph alu s, an d m ult idrug resist an t organ ism ven t ricu lit is. Additionally, reconstructive procedures for the m ore m assive injuries require a m ultidisciplinary e ort involving neurosurgery, plastic surgery, oral and m axillofacial surgery, otolaryngology– head and neck surgery, ophthalm ology, prosthodontics, and im aging/three-dim ensional fabrication experts.
References 1. Bell RS, Mossop CM, Dirks MS, et al. Early decom pressive cran iectom y for severe pen et rat ing an d closed h ead injur y du ring w ar t im e. Neu rosu rg Focu s 2010;28(5):E1 2. Ragel BT, Klim o P Jr, Mar t in JE, Te RJ, Bakken HE, Arm on da RA. War t im e d ecom p ressive cran iectom y: tech n iqu e an d lesson s learn ed. Neurosu rg Focu s 2010;28(5):E2
Com bat Cranial Operations
3. Fang R, Dorlac GR, Allan PF, Dorlac WC. In tercon t in en t al aerom edical evacuat ion of pat ien t s w ith t raum at ic brain inju ries during Operat ion s Iraqi Freedom an d En during Freedom . Neurosurg Focus 2010;28(5):E11 4. Kim KA, Wang MY, McNat t SA, Pin sky G, Liu CY, Gian n ot t a SL, Apu zzo ML. Vector an alysis correlat ing bu llet t rajector y to ou tcom e after civilian th rough -an d-th rough gun sh ot w oun d to th e h ead: u sing im aging cu es to p redict fat al ou tcom e. Neu rosu rger y 2005;57(4):737–747; d iscu ssion 737–747 5. Arm on da RA, Bell RS, Vo AH, et al. War t im e t rau m at ic cerebral vasospasm : recen t review of com bat casualt ies. Neurosurger y 2006;59(6):1215–1225; discussion 1225 6. Wor t m an n GW, Valadka AB, Moores LE. Preven t ion an d m an agem en t of in fect ion s associated w ith com bat-related cen t ral nervous system injuries. J Traum a 2008;64(3 Suppl):S252–256 7. Steph en s FL, Mossop CM, Bell RS, et al. Cran iop last y com plicat ion s follow ing w ar t im e decom pressive cran iectom y. Neurosu rg Focus 2010;28(5):E3 8. Hou sem an ND, Taylor GI, Pan W R. Th e angiosom es of th e h ead an d n eck: an atom ic st udy an d clin ical applicat ion s. Plast Reconst r Surg 2000;105(7):2287–2313
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24
Combat-Associated Penetrating Spine Injury Corey M. Mossop, Christopher J. Neal, Michael K. Rosner, and Paul Klim o Jr.
Introduction • Com bat-related pen et rat ing spin e inju ries (PSIs) are due to •
• •
rearm s an d exp losive devices, m ost n ot ably im p rovised exp losive d evices (IEDs). PSIs accoun t for up to 25% of all spin al cord injuries, of w h ich app roxim ately h alf presen t w ith com p lete parap legia an d m ore th an on e-qu arter are associated w ith oth er inju ries.1 An ar t icle com paring pen et rat ing an d blun t m ilitar y spin e injuries in th e recen t U.S. m ilit ar y con ict s (Operat ion Iraqi Freedom an d Operat ion En during Freedom ) repor ted th at of 598 injured ser vice m em bers, 104 (17%) sust ain ed spinal cord injuries, com prising 10% of blun t injuries an d 38% of p en et rat ing inju ries (p , 0.0001).2 Th e th oracic spin e accoun t s for th e m ajorit y of injuries, w ith th e lu m bosacral an d cer vical spin e follow ing in secon d an d th ird, respect ively.1,3 Given th e relat ion sh ip of kin et ic en ergy (KE), m ass (m ), an d velocit y (v) (KE 5 1/2m v 2 ), th e m ost crit ical factor a ect ing th e dest ruct iven ess of a project ile is its velocit y,4 m aking th e h igh -velocit y PSIs seen in com bat set t ings part icu larly d evastat ing.3,5 Th erefore, it is n ot surprising th at pat ien t s w ith m ilit ar y PSI in gen eral h ave a w orse n eu rologic inju r y on p resen t at ion an d h ave less poten t ial for n eu rologic recover y th an th ose w ith closed spin al cord t raum a.3
• • •
•
Indications • Fig. 24.1 depicts a t reat m ent algorithm for com bat-related PSI. • In com p lete sp in al cord inju r y w ith m ass lesion in th e sp in al can al, w ith or w ith out progressive n eurologic de cit ◦ W h ile th e literat u re is m ixed regarding th e exact ben e t of decom pressive su rger y (usu ally in th e form of m ult ilevel lam in ectom ies), m ost st ill favor op erat ive in ter ven t ion in a m edically st able p at ien t w ith an in com plete sp in al cord inju r y an d eviden ce of persisten t cord com pression such as
Discla im e r : Th e vie w s e xp r e sse d in t h e follow in g t e xt (o r p r e se n t a t ion , m a n u scr ip t , e t c.) a r e t h o se of t h e a u t h o r s a n d d o n ot n e ce ssa r ily r efle ct t h e officia l p o licy or p o sit ion of t h e De p a r t m e n t o f t h e Ar m y, De p a r t m e n t of t h e Nav y, De p a r t m e n t of Defe n se , n o r t h e U.S. Gove r n m e n t .
398
•
bon e or m etallic fragm en t s w ith in 24–48 h ours of th e in it ial injur y .1,3–10 An in com p lete spin al cord inju r y m ay exist w ithout im pingem en t on th e sp in al can al du e to th e en ergy released to th e surrou n ding st ru ct u res by th e p assage of th e project ile (i.e., “sh ock w ave”). In th is scen ario, surger y is n ot recom m en ded. CSF—cu t an eou s/p leu ral st u la Prolonged CSF leakage an d it s con com itan t in fect ious risks con st it u te a de n it ive surgical in dicat ion in PSI1,3 (Fig. 24.2). Fragm en t-in duced n er ve root com pression ◦ Pat ien t s w ith both clin ical an d radiograp h ic eviden ce of eith er bony or foreign body–in duced n er ve root com pression sh ou ld h ave th e involved root s decom pressed, ideally in th e rst 24–48 h ours after inju r y.1 Sp in al in stabilit y ◦ Sin ce th e m ajorit y of civilian PSIs are from low -m u zzle velocit y h an dgu n s an d kn ife w ou n ds, biom ech an ical in st abilit y is n ot , in gen eral, an issu e. As su ch , th ese pat ien t s require n o in st rum en t at ion an d/or fusion during operat ive in ter ven t ion .1,3,9,10 In com bat PSI, h ow ever, th e project iles involved (bullet s or fragm en t s from an explosive device) h ave a greater en ergy th at can be dissipated to th e surrou n ding an atom ic st ruct ures, th us in creasing th e likelih ood of spin al in st abilit y. With h igh -velocit y ballist ic t raum a, th e rate of in stabilit y can approach 20% an d is m ost com m on in injuries w ith a side-to-side t rajector y involving th e facet join t s bilaterally 7 ; h ow ever, th e con cept of spin al stabilit y rem ain s n ebulous an d ult im ately rests on a case-by-case con siderat ion of m u ltiple clin ical an d rad iograp h ic n dings w ith clin ical in t u it ion p laying an equ ally st rong role (Fig. 24.3). ◦ If t h e p at ien t h as a t ran sgast roin test in al an d u n st able sp in al inju r y, w e recom m en d t h at in st r u m en t at ion be p ost p on ed u n t il t h e p at ien t h as com p leted a fu ll cou rse of in t raven ou s an t ibiot ic t h erapy an d , if n ecessar y, t h e abd om en h as been t h orough ly d ebr id ed an d w ash ed ou t by a gen eral su rgeon . Recen t literat ure h as est ablish ed th at th e follow ing clin ical scen arios are not in dicat ion s (in an d of th em selves) for operat ive in ter ven t ion : ◦ Com plete spin al cord injur y (in th e absen ce of spin al in st abilit y or CSF leakage) (Fig. 24.4) 1,3–10 ◦ Woun d debridem en t/closure (in th e absen ce of gross w ou n d con t am in at ion ) 11 ◦ Copper- an d/or lead-based fragm en ts ▪ Given h ow rare h eavy m et al toxicit y is w ith PSI, th e com p osit ion of a fragm en t sh ould n ot dictate operat ive in terven t ion based on cu rren t evid en ce.3
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24 Com bat-Associated Penetrating Spine Injury
399
IV Em ergency Operations in Com bat
Fig. 24.2 This is an example of a complex exit wound from a penetrating spine injury. Management of dural violation and cerebrospinal uid stulas is paramount for wound healing in these patients. Vascularized tissue coverage is critical and may require the assistance of a plastic surgeon.
a
c
400
b
Fig. 24.3a–e This 27-year-old man sustained a highvelocit y gunshot wound that entered through the left neck (with associated tracheal/esophageal injuries and severe bilateral pulmonary contusions) and resulted in complex (a, b) multicolumn fractures of T2-4 with bilateral facet joint involvement, (c, d) complete cord transection, and a resultant complete (ASIA A) spinal cord injury. His tracheal and esophageal injuries were repaired and the entry/exit sites were debrided and closed while in theater. Because of the patient’s poor pulmonary and infectious status, his spinal injuries could not be addressed until post-injury day 15. (continued)
24
Com bat-Associated Penetrating Spine Injury
d
e Fig. 24.3 (continued) (e) At that time, he underwent a C7-T5 posterior spinal fusion with ligation of the thecal sac above the level of injury.
a
c
b
Fig. 24.4a–c This 39-year-old man sustained a gunshot wound that entered medial to the left scapula and traversed the left T2-3 pedicle, (a, b) exiting into the thoracic cage via the right T2-3 neuroforamen. He presented with a complete (ASIA A) spinal cord injury with no sacral sparing and MRI evidence of severe spinal cord injury (c). Given that the injury was thought to be stable and that there was no evidence of CSF leakage, it was managed nonoperatively with bracing.
401
IV Em ergency Operations in Com bat
Preprocedure Considerations
• Place in -dw elling (Foley) u rin ar y cath eter an d n asogast ric
Initial Evaluation
•
• Fu ll evalu at ion /resu scitat ion protocol in accordan ce w ith th e
•
•
• •
Advan ced Trau m a Life Su p port (ATLS) gu idelin es. Det ailed n eu rologic assessm en t to in clu d e m otor fu n ct ion in all key m u scle grou ps, sen sor y st at u s, re exes, an d sp h in cter ton e as det ailed by th e Am erican Spin al Inju r y Associat ion (ASIA) exam in at ion protocol.11 Exam in at ion of en t ran ce/exit w ou n ds for eviden ce of cerebrospin al uid (CSF) leakage. Th orough evaluat ion an d assessm en t of any associated soft t issue or visceral inju ries.
Radiographic Imaging Plain X-ray • Dem on st rates an atom ic align m en t , th e p resen ce or absen ce of overt bony injur y, an d th e locat ion of m ost retain ed foreign bodies.
Computed Tomography (CT) • Provides superior im aging of th e bony an atom y an d inju r y
•
•
pat tern (s). In addit ion , it also provides in form at ion regarding th e locat ion of retain ed foreign bodies. Met allic st reak ar t ifact from ret ain ed foreign bodies m ay degrade th e im aging. For cer vical spin e injur y, CT angiography (CTA) sh ou ld be perform ed on all pat ien t s to evaluate for carot id or vertebral arter y inju r y: disru pt ion , dissect ion , th rom bosis, or pseu doan eu r ysm form at ion . For th oracic or lum bar involvem en t , CTA an d CT ven ograp hy sh ou ld be don e to evalu ate for large vessel inju r y (e.g., th oracic an d abdom in al aort a, com m on iliac arteries, in ferior ven a cava). CT m yelograp hy is rarely in dicated in th e acu te set t ing; it m ay be valu able in a p at ien t in w h om m agn et ic reson an ce im aging (MRI) is con t rain dicated bu t in w h om con cern exist s for a com p ressive dural lesion n ot app aren t on bon e w in dow s su ch as an epidu ral or su bdu ral h em atom a.
•
t ube (con n ected to su ct ion ) to preven t u rin ar y reten t ion an d vom it ing/asp irat ion , resp ect ively. High -dose m ethylp redn isolon e is n ot in d icated in th e m an agem en t of PSI.14 St ress ulcer an d ph arm acologic deep vein th rom bosis prophylaxis is en couraged. High -dose broad-spect ru m in t raven ou s an t ibiot ics given for 7–10 days are indicated, especially in th e case of a t ran sab dom in al t rajector y w ith an associated bow el injur y.15,16
Operative Considerations/ Techniques Th e pat ien t w ith a PSI is at h igh risk for a w ide range of perioperat ive com plicat ion s th at th e surgeon m u st an t icipate an d t r y to preven t . In a recen t art icle by Possley et al,17 com plicat ion s—d e n ed as unplan n ed m edical even t s (su rgical or n on surgical) th at require furth er in ter ven t ion —occurred in 35% of ser vice m em bers w ith PSI w h o u n der w en t su rgical in ter ven t ion .
Tactical Scenario • Does th e cu rren t t act ical set t ing allow for operat ive in ter ven t ion in a safe, sterile environ m en t?
Associated Injuries • For t ran sth oracic injuries: Is th e pat ien t able to tolerate being •
pron e from a respirator y an d h em odyn am ic st an dpoin t? For t ran speriton eal injuries: Does th e pat ien t requ ire in terven t ion for a possible in test in al/vascu lar inju r y? Can th e pat ien t tolerate being pron e for th e durat ion of th e operat ion ?
Operative Field Preparation Radiographic Imaging • See Im aging sect ion for det ails • Plain X-rays: For p osterior th oracic ap p roach es to determ in e
MRI (When Available)
th e n um ber of ribs for localizat ion
• Excellen t for sh ow ing soft t issue an atom y: th e in tegrit y of th e spin al cord, n er ve root s, ligam en ts, m u scles, join t cap su les, an d in ter ver tebral disks. MRI is u su ally con t rain d icated in PSI if th ere are ret ain ed m et allic fragm en ts.
Initial Medical Management 12 • Adm ission to m on itored set t ing. • Im m obilizat ion u n t il spin al st abilit y est ablish ed . • Avoid hypoten sion (systolic blood p ressu re , 90 m m Hg) an d m ain t ain m ean ar terial pressu res at 85–90 m m Hg for th e rst 7 days if th e p at ien t h as su ered a sp in al cord inju r y.13 ◦ Use carefu l in t raven ou s hydrat ion w ith p ressors ( dop am in e) if n eeded to m ain t ain m ean ar terial pressu re (MAP) goals.
402
Equipment/Set-Up • • • • • • • •
Head ligh t , lou pes, bip olar/Bovie cau ter y In t raop erat ive u oroscopy May eld h ead h older: For posterior cer vical ap p roach es Pron e t able: Open /closed Jackson table w ith Wilson fram e or bolsters depen ding on surgeon preferen ce for posterior th oracolum bar approach es Basic sp in e t ray w ith Kerrison rongeurs High -sp eed drill Basic spin al in st rum en t at ion t ray: Sh ou ld h ave on st an d-by for all cases Du ral rep air m aterials: Sh ou ld h ave ap p ropriate su t u res (4-0 braided nylon , etc.) available for prim ar y dural repair,
24
•
syn th et ic du ral su bst it u tes, an d du ral sealan t s for all cases. Also, m aterials for th ecal sac ligat ion if in dicated (see Fig. 24.1 an d Op erat ive Tech n iqu e sect ion ) sh ou ld be available. Lu m bar drain : Sh ould h ave available if n eeded for CSF diversion in lu m bosacral decom p ression s
Anesthesia Issues • Con sider aw ake • •
Com bat-Associated Penetrating Spine Injury
• Ar terial lin e to m ain t ain m ean ar terial pressure . 85 m m Hg for th e en t iret y of th e case
Neuromonitoring • Recom m en ded if available for m on itoring of som atosen sor y evoked p oten t ials (SSEPs) an d elect rom yograp hy (EMG)
beropt ic in t ubat ion if spin al in stabilit y
su spected Prophylact ic in t raven ous an t ibiot ics 30 m in utes prior to in cision if n ot already on broad-sp ect rum an t ibiot ics Foley cath eter
Prepping/ Incision • Sh ave w ith elect ric h air clip p ers • Su rgical prep arat ion in th e st an dard sterile fash ion
403
IV Em ergency Operations in Com bat
Operative Procedure Positioning (Fig. 24.5a, b)
a
404
24
Com bat-Associated Penetrating Spine Injury
b
Figure
Procedural Steps
Pearls
Fig. 24.5
(a) Posterior cervical approach: Prone in May eld head holder on standard operating room table w ith appropriate padding and arms tucked on the patient’s sides in reverse Trendelenburg to promote venous drainage. Use uoroscopy to con rm normal physiologic cervical alignment.
• Use uoroscopy to plan the incision to span at
(b) Posterior thoracolumbar approaches: Prone on open/ closed spinal table w ith Wilson frame or bolsters depending on surgeon preference. For pathology above T6-7, the arms should be tucked at the patient’s side. Below this level, the arms may be abducted and placed on a padded surface.
•
least t wo levels above and below the levels of planned decompression and/or fusion. Consider both anteroposterior and lateral uoroscopy to aid in localization for posterior thoracic approaches (requires preoperative knowledge of rib num ber). Bony injury or retained m etallic fragm ents will allow rapid localization of the injured level(s).
405
IV Em ergency Operations in Com bat
Dissection (Fig. 24.6)
Figure
Procedural Steps
Fig. 24.6
A midline incision is made w ith no. 10 scalpel blade (length as dictated by uoroscopic localization). Using monopolar cautery, continue a midline dissection w ith the assistance of self-retaining retractors to the level of the spinous processes. Verify operative level uoroscopically. Complete a bilateral subperiosteal dissection on the planned levels of decompression to the medial edges of the facet joints. If an instrumented fusion is not planned, take special care to leave the facet joint capsules intact.
406
24
Com bat-Associated Penetrating Spine Injury
Laminectomy (Fig. 24.7)
Figure
Procedural Steps
Fig. 24.7
Using the high-speed drill and Leksell/ Kerrison rongeurs, remove the spinous processes and perform laminectomies at least one level above and below the pathologic level. Remove the underlying ligamentum avum w ith Kerrison rongeurs.
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IV Em ergency Operations in Com bat
Decompression (Fig. 24.8)
408
Figure
Procedural Steps
Fig. 24.8
Carefully remove any foreign bodies or bony fragments causing any compression on the underlying nerve roots, thecal sac, or spinal cord.
24
Com bat-Associated Penetrating Spine Injury
Dural Exploration/ Repair (Fig. 24.9)
Figure
Procedural Steps
Pearls
Fig. 24.9
Carefully explore the thecal sac and exiting nerve roots for the presence of any dural tears.
• Further augm entation with synthetic dural substitutes •
If present, attempt primary repair w ith 4-0 braided nylon suture that can be augmented by the use of either dorsal autologous fascia/muscle or a suturable synthetic dural substitute for larger defects.
•
and sealants m ay then be at tempted. In the instance of CSF leakage in the set ting of a complete spinal cord injury, consideration m ay then be given to ligation of the thecal sac as a prim ary m eans of halting CSF egress. Consider intraoperative placement of a lum bar drain for protection of lum bosacral dural repairs.
Perform Valsalva maneuver to judge the integrity of the dural repair.
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IV Em ergency Operations in Com bat
Instrumentation/ Fusion (See Chapters 14 and 15)
in th ose pat ien t s w ith com plete spin al cord injur y an d th ose w ith in com plete inju r y but w h o are n on am bulator y.
• If in dicated, p erform in st ru m en t at ion an d fu sion after th e prim ar y operat ive goals of decom pression an d dural repair h ave been accom plish ed.
Closing • Su ct ion can ister/Jackson -Prat t drain (s) if n eeded (avoid w h en • • •
dural repair perform ed). Close dorsal fascia in a w atert igh t m an n er w ith in terrupted 0-0 braided absorbable sut ures. Close subcu tan eou s t issu e w ith inverted, in terrupted 2-0 braided absorbable sut ures. Close skin w ith either staples or running 2-0/3-0 nylon sut ure.
Postoperative Management • Adm ission to a m on itored set t ing w ith con t in u ed blood p res• • • •
•
•
410
su re goals as sp eci ed for u p to 7 days after th e in it ial inju r y. Mon itor drain ou t p u t w ith rem oval w h en ou t p u t is m in im al or if any con cern exists for CSF leakage. Obt ain early p ostop erat ive im aging if in st ru m en t at ion p erform ed. Main tain ap prop riate an t im icrobial coverage w ith in t raven ou s an t ibiot ics for 7 days if visceral injur y is con rm ed. In th e case of a low th oracic or lu m bar du ral rep air, m ain t ain th e pat ien t at for 48–72 h ours postoperat ively. For cer vical or proxim al th oracic dural repairs, m ain tain th e pat ien t w ith th e h ead of bed at 90 degrees for 48–72 h ours in th e postop erat ive set t ing. In th e case of m id-th oracic du ral rep airs, th e posit ion ing of th e pat ien t postoperat ively is at th e discret ion of th e operat ing surgeon . Mech an ical deep vein th rom bosis (DVT) p rop hylaxis sh ou ld be in it iated u pon adm ission an d con t in ued th rough out surger y an d p ostop erat ively. W h en it is determ in ed to be ap p ropriate, in st it ute ph arm acologic DVT prophylaxis. Recom m en d postoperat ive scoliosis sur vey in th e sit t ing or stan ding posit ion (depen ding on th e pat ien t’s clin ical st at u s) to p rovide baselin e kn ow ledge regarding region al an d global spin al balan ce. Th is sh ou ld be repeated at regu lar in ter vals (as determ in ed by th e operat ing surgeon ) to m on itor for any deform it y p rogression in th e p ost-su rgical set t ing, part icularly
References 1. Bu xton N. Spin al injur y. In: Brooks A, et al, eds. Ryan’s Ballist ic Trau m a: A Pract ical Gu ide. Lon don : Sp ringer; 2011: 341–347 2. Blair JA, Possley DR, Pet eld JL, et al. Milit ar y p en et rat ing sp in e injur y com pared w ith blu n t . Spin e J 2012;12:762–768 3. Klim o P, Ragel BT, Rosn er M, et al. Can su rger y im prove n eu rological fun ct ion in penet rat ing spin al injur y? A review of th e m ilitar y an d civilian literat ure an d t reat m en t recom m en dat ion s for m ilit ar y neu rosurgeon s. Neurosurg Focus 2010;28(5):E4 4. DeMu th W E Jr. Bu llet velocit y as ap p lied to m ilit ar y ri e w ou n ding capacit y. J Traum a 1969;9:27–38 5. Blair JA, Pat zkow ski JC, Sch oen feld AJ, et al. Are spin e inju ries sust ain ed in bat tle t ru ly di eren t? Spin e J 2012;12:824–829 6. Clin ical assessm en t after acute cer vical spin al cord inju r y. Neurosu rger y 2002;50(3 Suppl):S21–29 7. Man agem en t of acu te spin al cord inju ries in an in ten sive care un it or oth er m on itored set t ing. Neurosurger y 2002;50(3 Suppl): S51–57 8. Blood pressu re m an agem en t after acute spin al cord injur y. Neurosu rger y 2002;50(3 Suppl):S58–62 9. St illerm an CB. Use of m ethylpred n isolon e as an adju n ct in th e m an agem en t of pat ien t s w ith pen et rat ing spin al cord inju r y: outcom e an alysis. Neurosurger y 1996;39:1141–1149 10. Lin SS, Vaccaro AR, Reisch S, et al. Low -velocit y gu n sh ot w ou n ds to th e spin e w ith an associated t ran speriton eal injur y. J Spin al Disord 1995;8:136–144 11. Qu igley KJ, Place HM. Th e role of debridem en t an d an t ibiot ics in gun sh ot w oun ds to th e spin e. J Trau m a 2006;60:814–820 12. Aarabi B, Alibaii E, Taghipur M, et al. Com parative study of functional recovery for surgically explored and conservatively m anaged spinal cord m issile injuries. Neurosurgery 1996;39:1133–1140 13. Du z B, Can sever T, Secer HI, et al. Evalu at ion of sp in al m issile injuries w ith respect to bullet t rajector y, su rgical in dicat ion s an d t im ing of su rgical in ter ven t ion : a n ew gu idelin e. Spin e 2008;33:E746–E753 14. Ham m ou d MA, Haddad FS, Mou farrij NA. Sp in al cord m issile injuries during the Leban ese civil w ar. Surg Neu rol 1995;43: 432–442 15. Velm ah os GC, Degian n is E, Har t K, et al. Ch anging p ro les in sp in al cord injuries an d risk factors in uen cing recover y after pen et rat ing injuries. J Traum a 1995;38:334–337 16. Waters RL, Sie IH. Sp in al cord inju ries from gu n sh ot w ou n ds to th e sp in e. Clin Or th op Relat Res 2003;408:120–125 17. Possley DR, Blair JA, Sch oen feld AJ, et al. Com plicat ion s associated w ith m ilit ar y sp in e inju ries. Spin e J 2012;12:756–761
V
Reconstructive Surgery
25
Replacement of Cranial Bone Flap Jam ie S. Ullm an
Introduction Cran iotom y bon e aps are often frozen or stored in th e su bcu t an eous layer of th e abdom in al w all after decom pressive cran iectom y for in t racran ial hyp erten sion from t rau m at ic brain inju r y, cerebrovascular disease, or oth er causes. Bon e ap restorat ion w ill be n eeded on ce th e acute issues h ave resolved. Th ere is n o con sen sus regarding th e opt im al t im ing of bon e ap rep lacem en t .1–4 Replacem en ts can be p erform ed from as lit tle as 2 w eeks to m ore th an 1 year after inju r y.5,6
Indications • Su cien t abatem en t of sw elling h as occu rred w ith th e brain • •
•
n oted on clin ical or radiological exam in at ion to be “su n ken ” or n ot sign i can tly prot ruding beyon d th e defect . Th ere is n o in dicat ion of system ic or local in fect ion , or eviden ce of sign i can t decubit us ulcers in proxim it y to th e cran ial defect or in cision . In creasing leth argy or n ew focal de cit is p resen t on exam in at ion an d n ot oth er w ise at t ribu ted to m et abolic or st ru ct ural abn orm alit ies. Such de cit s are poten t ially due to th e e ects of altered cerebrosp in al u id (CSF) dyn am ics or at m osp h eric pressu re on th e brain . Th ere m ay be sign i can t brain depression at th e defect an d com puted tom ography (CT) m ay reveal brain sh ift ing to th e con t ralateral side. Eviden ce suggest s th at earlier restorat ion of cran ial in tegrit y can im prove n eurologic de cits in addit ion to h elping th ose pat ien t s w ho exh ibit early sign s of com m u n icat ing hydrocep h alu s.5,7,8
Fig. 25.1 Preoperative computed tomography study indicating a large left cranial defect. The brain is largely ush with the bone edges.
Medication • Th e auth or prefers van com ycin an d gen t am icin for an t ibi-
•
ot ic prophylaxis, provided th e pat ien t does n ot h ave ren al failu re or oth er con t rain dicat ion s. Often pat ien t s h ave been h ospit alized for sign i can t p eriods of t im e an d th ere is a possibilit y for th e skin to be colon ized w ith m eth icillin -resist an t Staphylococcus aureus. Diphenylhydantoin is adm inistered at 15 m g/kg in nonallergic patients w ho are not on standing antiepileptic m edication. Levetiracetam can be used alternatively at a 1000-m g loading dose.
Preprocedure Considerations Radiographic Imaging
Operative Field Preparation • Alcoh ol prep is perform ed before povidon e iodine or chlorh ex-
• CT is essen t ial to evalu ate th e con dit ion of th e brain an d it s relat ion sh ip w ith th e defect prior to perform ing recon st ruct ion (Fig. 25.1).
412
•
idin e application . Th e in cision s are m arked an d in lt rated w ith 1% lidocain e w ith epin eph rin e 1:100,000.
25
Replacem ent of Cranial Bone Flap
Operative Procedure Positioning and Preparation (Fig. 25.2a, b)
b
a
Figure
Procedural Steps
Pearls
Fig. 25.2
(a) Patient positioning. The head is turned approximately 60 degrees in the contralateral direction and the prior frontotemporoparietal scalp incision is exposed and prepared.
• While this chapter discusses subcut aneously placed autogenous
(b) The abdominal incision housing the subcutaneously placed bone ap is exposed and prepared.
bone graft s as opposed to those stored in a freezer, the techniques of reopening the craniotom y incision and bone ap replacem ent rem ain the sam e. For the com m only perform ed hem icraniectom y or frontotem poropariet al (occipit al) defect, the patient is positioned in the supine position with the head t urned approxim ately 60 degrees in the contralateral direction. The head is placed on a donut and a roll is placed under the ipsilateral shoulder. For bifront al craniectom ies, the patient is placed supine, head straight position; the subcut aneous dissect ion described forthwith is essentially the sam e (see Chapter 26).
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Skin Incision (Fig. 25.3a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 25.3
(a) The incision is made w ith a no. 10 blade from the superoanterior frontal region rst and opened in progressive fashion. The bone edge is palpated under the incision. If there is no bone edge, a straight clamp is used to separate the pericranium from the galea to provide protection from the knife blade w hen bone cannot be palpated underneath the incision.
• In cases where the pericranium was elevated
(b) The incision is opened in stages starting w ith the frontal, superior portion, placing galeal clamps w hen this layer has been properly separated. The plane betw een the pericranium and galea is developed w ith sharp dissection. The scalp layer can be properly re ected forw ard by developing the plane betw een the vascularized pericranium and the galea.
414
with the scalp during the initial procedure, this layer is virtually unscarred. The galea– pericranial plane is developed with a Met zenbaum scissors. Unscarred planes can also be developed with blunt dissection using a gauze sponge. The pericranium will cover the defect as the new “pseudodural” plane. If the pericranium is intact, the defect area will be well-vascularized and the underlying duraplast y or brain tissue will not be seen.
25
Replacem ent of Cranial Bone Flap
Subcutaneous Dissection (Fig 25.4)
Figure
Procedural Steps
Pearls
Fig. 25.4
After dissection becomes limited, the skin is opened further. Progressive alternation of skin opening and galeal–pericranial plane dissection is completed until the w ound is completely reopened and the entire scalp ap has been re ected. Galeal clamps are placed for hemostasis. The scalp ap is then retracted anteriorly w ith scalp hooks or 2-0 braided nylon sutures attached to rubber bands and clamps. Hemostasis is achieved w ith mono and bipolar cautery.
• Maintaining vascularized tissue in the epidural plane can help com bat potential infections and prom ote osteoinduction.9 Surgeons who have previously perform ed a duraplast y with collagen or allo/xenographic dural substitutes m ay choose to dissect the pericranial– dural plane. However, if the cranioplast y is perform ed prior to su cient incorporation of the dural graft m aterial, the resulting dural layer m ay not yet have su cient vascularit y.
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Identifying the Temporalis Muscle and Separation (Fig. 25.5a–c)
a
b
416
25
Replacem ent of Cranial Bone Flap
c
Figure
Procedural Steps
Pearls
Fig. 25.5
(a) Monopolar cautery or a scalpel is used along the posterior bone edge to expose and incise the temporalis muscle for dissection and transposition.
• There is scant discussion in the literature •
(b) The plane betw een the muscle layer and the underlying duraplasty is developed w ith dissecting scissors. If a dural plane is not w ell established underneath the muscle during the initial procedure, disruption of the cerebral cortex may occur. Wellpreserved muscles can be separated from the underlying tissues safely using sharp dissection and leaving behind a thin layer of muscle bers. (c) The fascia is incised w ith the temporalis muscle and re ected inferiorly w ith a 2-0 suture although it is not alw ays easy to distinguish the temporalis fascia from the surrounding tissues.
•
about the temporalis m uscle disposition during cranioplast y.10 The author at tempts to transpose the temporalis if there is su cient m uscle volum e to warrant such at tempts. If the bone ap is replaced over functional m uscle tissue, the patient m ay experience m ovement restriction and discomfort during m astication. If signi cant m uscle atrophy is present along with the risk of disrupting cerebral cortex, it is advisable to abandon m uscle transposition. Methods to preserve the temporalis during the initial craniectomy procedure have been reported.11
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Subcutaneous Abdominal Bone Flap Retrieval (Fig. 25.6a, b)
a
b
Figure
Procedural Steps
Fig. 25.6
(a) The prior abdominal w all incision is opened w ith a no. 10 blade dow n to the bone. The bone is dissected from its “pseudocapsule” and surrounding tissues w ith a periosteal elevator along the super cial surface, then the lateral edges, then the undersurface, then, lastly, the superior, inferior, and medial edges. A laparotomy pad is placed in the abdominal w all pocket to assist w ith hemostasis. The bone is brie y soaked in a half peroxide/saline solution then irrigated clean w ith saline. Debris is scraped from the bone surface w ith a periosteal elevator. (b) Before bone ap replacement, tangential holes are created w ith the drill along the superior temporal line for temporalis xation to re -create the temporalis insertion, if the temporalis is to be transposed.
418
Pearls
25
Replacem ent of Cranial Bone Flap
Bone Flap Replacement (Fig. 25.7a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 25.7
The craniectomy defect is prepared to receive the graft. Hemostasis, especially epidural, is obtained w ith bipolar coagulation and irrigation. The bone edges are palpated. The posterior and anteroinferior portion of the pericranial graft is left attached to its vascular pedicle.
• If extant, protrusion of the brain through the defect during
(a) The bone ap is then placed into the defect for alignment and to mark the areas for titanium plate placement. Titanium plates are screw ed onto the graft bone edge. The graft is then replaced onto the defect and the plates are secured to the bone edge. Where pericranium has been left on the bone surface to maintain its vascularity, the screw is placed through the pericranium.
•
surgery can be controlled with head of bed elevation, m annitol, and/or mild hyperventilation. If an intradural cyst is causing protrusion, it can be drained with ultrasonic guidance prior to replacing the bone ap. On occasion the author has elected to hinge the bone ap at the superior edge to allow brain swelling to decrease slowly over tim e. If hinged, placem ent of plates around the circum ference of the ap can help to prevent sinking of the ap once the swelling resolves. It is often not necessary to secure these other plates in the future, but the option rem ains open. In cases where the bone has rem odeled and the graft t is not precise, a bur m ay be used to m ake the bone edges more even. (b) In such cases where there m ay be signi cant gaps or a good deal of temporal and sphenoid bone resection was perform ed at the initial procedure, titanium mesh m ay be placed atop the graft and the inferior bone edges and secured with titanium screws.
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Temporalis Transposition (Fig. 25.8a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 25.8
(a) If preserved, the temporalis muscle is secured to the holes created as its “insertion” at the superior temporal line w ith 2-0 braided nylon sutures to complete its transposition.
• It is optional to place polym ethylm ethacrylate or
(b) The posterior portion of the temporalis is reapproximated w ith 2-0 braided nylon suture or absorbable suture.
420
hydroxyapatite atop the m esh or any other existing defect after the bone ap has been replaced. Precontoured m aterials for these defects are available (see Chapter 26).
25
Replacem ent of Cranial Bone Flap
Completed Construct (Fig. 25.9)
Figure
Procedural Steps
Fig. 25.9
Photograph of completed construct prior to closing.
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V Reconstructive Surgery
Closing Cranial Incision • Th e w oun d is h eavily irrigated. • A m ediu m su ct ion d rain age device is p laced in th e su bgaleal • •
plan e. Th e scalp is approxim ated w ith 3-0 braided absorbable su t ure in an inverted, in terrupted fash ion . Th e skin is closed w ith 3-0 nylon or w ith staples.
Abdominal Incision • After h em ost asis is obt ain ed at th e abdom in al site w ith m o• •
n op olar cauter y, an opt ion al su ct ion drain age device is placed in th e abdom in al w all cavit y. Th e pseudocapsu le an d fat layers are closed w ith 3-0 absorb able su t u re. Th e skin is closed w ith st aples or 3-0 nylon sut ures.
Postoperative Management
Fig. 25.10 Computed tomography head scan after bone ap replacement.
Monitoring • It is th e au th or’s pract ice to p lace th e p at ien t in a m on itored set t ing overn igh t in th e p ostoperat ive period to obser ve for seizu re act ivit y or eviden ce of in t racran ial bleeding.
Medication • Th e prophylact ic an t iepilept ic agen t is cont in u ed for a total of •
7 days provided th ere are n o in terim seizures. It is opt ion al to give t w o to th ree doses of prop hylact ic an t ibiot ics in th e im m ediate postop erat ive p eriod .
Radiographic Imaging • A p ostoperat ive CT scan m ay be obtain ed to evalu ate for ext ra-axial collect ion s or oth er h em orrh age (Fig. 25.10).
Further Management • Drain s are rem oved in 1 or 2 days. • Skin su t u res or stap les are rem oved after 2 w eeks.
Special Considerations Explan ted craniotom y aps can also be stored in sub-zero freezers u n der aseptic con dit ion s.12,13 Th e available literat u re suggests th at th e rate of in fection or com plicat ion s do n ot di er bet w een grafts stored by either m ethod.9,12,13 The disadvan tage of subcutan eously stored bone grafts is that bone rem odeling
422
occurs over tim e. Though this tim e period is not certain, it is likely to occur som etim e after 3 m onths of storage.14 Su bcu tan eously stored bone grafts have been noted to h ave histological evidence of both bone destruct ion and osteogenesis.14,15 Th erefore, earlier placem en t of th is t ype of stored graft m ay be preferable. Frozen grafts m ay have a high er incidence of bone resorption on ce im planted, especially in children.9,12,16,17 This resorpt ion m ay also be m it igated by earlier bon e ap replacem en t.6 W h ile th e focus of th is ch apter does n ot in clude in dicat ion s for sh u n t ing, qu est ion s arise as w h eth er to p erform a sh u n t or h ow to m an age an exist ing sh u n t p rior to bon e ap rep lacem en t .1,8,18–20 It is th e au th or’s p ract ice th at , w h en p at ien t s develop post t rau m at ic n orm al p ressu re hydroceph alu s w ith n o prot rusion of brain th rough th e defect an d pat ien ts are ready for bon e ap restorat ion , th e lat ter is perform ed rst w ith carefu l postoperat ive m on itoring of th e n eu rologic exam in at ion an d radiograph s. Th e sh u n t is th en p laced in a delayed fash ion (1 to 2 w eeks postoperat ively) to allow for ext ra-axial air or uid to resolve prior to sh un t placem en t so as to avoid p oten t iat ing a collect ion in th is space. In pat ien t s w h o h ave sh un t s prior to cran ioplast y, th e clin ical con dit ion m ay allow for tem porar y sh u n t occlu sion in th e pre- an d p erioperat ive p eriod w ith close m on itoring to e ect brain exp an sion an d th ereby m in im izing su bdu ral collect ion d evelop m en t . How ever, th is decision is based u pon taking in to con siderat ion th e pat ien t’s clin ical con dit ion , h istor y of sh un t depen den ce, an d radiograph ic st udies. Program m able sh un t valves m ay perm it th e pract it ion er to adju st drain age p ressure to a h igh er set t ing prior to cran ioplast y. After w ard, progressive reduct ion s in th e pressure set t ings can h elp p reven t su bdu ral collect ion s.1 Th ese p rogram m able valves m ay also be u sefu l in sh orten ing th e t im e fram e bet w een cran ioplast y an d delayed de n ovo sh u n t ing.
25
References 1. Ch eng YK, Weng HH, Yang JT, et al. Factors a ect ing graft in fect ion after cran ioplast y. J Clin Neurosci 2008;15:1115–1119 2. Liang W, Xiaofeng Y, Weigu o L, et al. Cran iop last y of large cran ial defect at an early st age after decom pressive cran iectom y perform ed for severe h ead injur y. J Cran iofac Surg 2007;18: 526–532 3. Iw am a T, Yam ada J, Im ai S, et al. Th e u se of frozen au togen ou s bon e aps in delayed cran ioplast y revisited. Neurosurger y 2003;52:591–596 4. Hu ang YH, Lee TC, Yang KY, et al. Is t im ing of cran ioplast y follow ing post t raum at ic cran iectom y related to n eurological ou tcom e? In t J Su rg 2013;11:886–890 5. Beau ch am p KM, Kash u k J, Moore EE, et al. Cran iop last y after post injur y decom pressive cran iectom y: is t im ing of th e essen ce? J Trau m a 2010;69:270–274 6. Piedra MP, Th om pson EM, Selden NR, et al. Opt im al t im ing of autologous cran ioplast y after decom pressive cran iectom y in children . J Neurosurg Pediat r 2012;10:268–272 7. Gran t GA, Jolley M, Ellen bogen RG, et al. Failu re of au tologou s bon e-assisted cran ioplast y follow ing decom pressive cran iectom y in ch ildren an d adolescen t s. J Neurosurg 2004;100:163–168 8. Han PY, Kim JH, Kang HI, et al. Syn drom e of th e sin king skin - ap secon dar y to th e ven t riculoperiton eal sh un t after cran iectom y. J Korean Neu rosu rg Soc 2008;43:51–53 9. Flan n er y T, McCon n ell RS. Cran iop last y: w hy th row th e bon e ap out? Br J Neurosurg 2001;15:518–520 10. Zingale A, Albanese V. Cryopreservation of autogenous bone ap in cranial surgical practice: w hat is the future? A grade B and evidence level 4 m eta-analytic study. J Neurosurg Sci 2003;47:137–139
Replacem ent of Cranial Bone Flap
11. Di Rien zo A, Iacoangeli M, Alvaro L, et al. Autologou s vascularized dural w rapping for tem poralis m uscle preser vat ion an d recon st ruct ion after decom pressive cran iectom y: report of t w en t yve cases. Neurol Med Ch ir (Tokyo) 2013;53:590–595 12. Missori P, Polli FM, Pesch illo S, et al. Double dural patch in decom pressive cran iectom y to preser ve th e tem poral m uscle: tech n ical n ote. Surg Neurol 2008;70:437–439 13. Oh CH, Par CO, Hyu n DK, et al. Com parat ive st udy of outcom es bet w een sh un t ing after cran ioplast y an d in cran ioplast y after sh un t ing in large con cave accid cran ial defect w ith hydroceph alus. J Korean Neu rosurg Soc 2008;44:211–216 14. St iver SI, Winterm ark M, Man ley GT. Reversible m on oparesis follow ing d ecom p ressive h em icran iectom y for t rau m at ic brain inju r y. J Neu rosurg 2008;109:245–254 15. Car vi Y Nievas MN, Hollerh age HG. Early com bin ed cran ioplast y an d program m able sh un t in pat ient s w ith skull bon e defect s an d CSF circu lat ion disorders. Neu rol Res 2006;28:139–144 16. Waziri A, Fusco D, Mayer SA, et al. Postoperat ive hydrocephalus in pat ient s undergoing decom pressive h em icraniectom y for isch em ic or h em orrh agic st roke. Neurosurger y 2007;61:489–493 17. Dun isch P, Walter J, Sakr Y, et al. Risk factors of asept ic bon e resorpt ion : a st udy after autologous bon e ap rein ser t ion due to decom pressive cran iectom y. J Neurosurg 2013;118:1141–1147 18. Movassagh i K, Ver Halen J, Gan ch i P, et al. Cran ioplast y w ith sub cu t an eou sly p reser ved au tologou s bon e graft s. Plast Recon st r Surg 2006;117:202–206 19. Acikgoz B, Ozcan OE, Erbengi A, et al. Histopath ologic an d m icroden sitom et ric an alysis of cran iotom y bon e aps preser ved bet w een abdom in al fat and m u scle. Surg Neurol 1986;26:557–561 20. Heo J, Park SQ, Ch o SJ, et al. Evaluat ion of sim ult an eous cran ioplast y an d ven t riculoperiton eal sh un t procedures. J Neurosurg 2014;121(2):313–318
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26
Techniques of Alloplastic Cranioplasty Erin N. Kiehna and John A. Jane Jr.
◦ Bon e w as con tam in ated at th e t im e of inju r y (foreign body
Introduction W hen an autologous cranioplast y is not an option—w hether from contam ination, infection, fragm entation, bony reabsorption, or grow th in the cranial vault (in children)—neurosurgeons often have to turn to im plantable synthetic cranioplasties. The goals of a cranioplast y rem ain the sam e: lasting repair of the cranial defect w ith good anatom ic contour. This can be perform ed at any tim e point follow ing a reduction in brain swelling.1 Since the 1600s, neurosurgeons have experim ented w ith several di erent constructs in the quest for the perfect cranioplast y.2 Recent developm ents in com puter-aided design and m anufacturing, tissue engineering, and osteoinductive capabilities allow for the fabrication of an alloplastic im plant w ith excellent aesthetics that w ithstands biom echanical stresses and allow s for tissue integration.3
Indications
con tam in at ion or open fract ures) ◦ Bon e ap in fect ion /osteom yelit is ◦ Sign i can t dispropor t ion bet w een th e skull an d th e bon e ap resu lt ing in aesth et ically u npleasing ou tcom e ▪ Bony reabsorpt ion follow ing in it ial autologou s cran iop last y (Fig. 26.1). ▪ Bony rem odeling ▪ Sign i can t grow th of th e cran ial vault (in ch ildren ) ◦ Grow ing skull fract ures an d t rau m at ic defect s in th e sku ll (Fig. 26.2)
Preprocedure Considerations Radiographic Imaging • Neu roim aging is requ ired p rior to any cran iop last y to evalu -
• Su cien t abatem en t of sw elling h as occu rred w h en n eu roim aging dem on st rates th at brain is n ot prot ruding beyon d th e defect an d lacks any eviden ce of system ic or local in fect ion . ◦ Un suitabilit y of au tologous cran ioplast y ◦ Bon e w as fragm en ted (prim ar y inju r y w as a dep ressed sku ll fract u re)
•
ate th e con dit ion of th e brain , it s relat ion sh ip w ith th e cran ial defect , any degree of hydroceph alus, extern al hydroceph alu s, an d/or leptom en ingeal cyst s. Magn et ic reson an ce im aging (MRI), w h ile n ot n ecessar y, allow s for m ore det ail of th e brain ; it also m ay be m ore su itable for ch ildren w h en th ere is a goal to lim it radiat ion exposu re.
Fig. 26.1 Three-dimensional CT scan of bony reabsorption following cranioplast y in an infant.
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Techniques of Alloplastic Cranioplast y
• Com puted tom ography (CT) allow s for visualization of the •
thickness of the bone to determ ine the “splitabilit y” in children. A th ree-dim en sion al an atom ic CT is n ecessar y for con st ruct ion of custom , im plan t able cran ioplast ies.
Medication • Antibiotic prophylaxis includes the standard preoperative dose •
30–60 m inutes prior to skin incision. Som e neurosurgeons also provide 24 hour antibiotic prophylaxis postoperatively. An t iepilept ic prophylaxis m ay be con sidered in pat ien t s w h o are n ot on stan ding an t iep ilept ic m edicat ion . Ou r in st it u t ion u t ilizes ph enytoin or levet iracet am .
Operative Site Preparation • Th e skin in cision used for th e decom pressive cran iectom y or • • • • Fig. 26.2 Growing skull fracture in an infant.
•
cran iotom y site is t ypically su cient . In cision s sh ou ld be m ad e as cosm et ic as possible, st aying beh in d th e h airlin e an d p reser ving blood ow to th e scalp ap . Approxim ately 1–2 cm of h air clipping m ay be perform ed. Th e skin is prepped as per physician preferen ce, w ith th e recom m en dat ion th at alcoh ol is u sed during a stage of th e skin clean sing process. Th e in cision s are m arked an d in lt rated w ith 0.2% ropivacain e w ith epin eph rin e 1:100,000. Algorith m for cran ioplast y select ion (Fig. 26.3).
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Bony defect
s/p calvarial t um or resect ion
s/p in fect ion delayed reconst ruct ion
s/p t rau m a
Im m ed iate cran iop last y w ith pre-ordered im p lan t
Im m ed iate cran iop last y w ith p orou s polyethylen e or HA or PMMA con tou red on th e field
If sw elling th en delayed recon st ru ct ion
Bon e flap in tact an d n ot con tam in ated ? Au tologou s bon e
At tem pt p at ien t ow n bon e if available (an d n ot con tam in ated)
Bon e flap fragm en ted or con tam in ated
Use p re-ordered im p lant for large con st ru ct s
Sm all defect: Titan iu m m esh , porou s polyethylen e, HA or PMMA con tou red on th e field Large defect: Order cu stom im p lan t if au tologou s bon e flap is n ot suitable for reim plan tat ion
If n o sw elling th en im m ediate reconst ru ct ion
Bon e flap in tact an d n ot con tam in ated? Autologou s bon e Bon e flap fragm en ted or con tam in ated
Sm all defect: Titan iu m m esh , p orou s p olyethylen e, HA or PMMA con tou red on th e field Large defect: Ord er custom im p lan t if au tologou s bon e flap is n ot su itable for reim p lan tat ion Fig. 26.3 Algorithm for cranioplast y selection. HA, hydroxyapatite; PMMA, polymethylm ethacrylate.
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Techniques of Alloplastic Cranioplast y
Operative Procedure Positioning Unilateral Craniectomy (Fig. 26.4)
Figure
Procedural Steps
Pearls
Fig. 26.4
For most cranioplasties, it is su cient to place the head on a donut or horseshoe w ith a roll placed under the ipsilateral shoulder for relief of strain. The head is turned approximately 60 degrees in the contralateral direction and the prior frontotemporoparietal scalp incision is exposed and prepared.
• For cranioplasties that extend to the occipital region, it m ay be necessary to “pin” the patient to optim ize the surgical eld.
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Positioning for Bifrontal Craniectomy (Fig. 26.5)
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Figure
Procedural Steps
Pearls
Fig. 26.5
For bifrontal cranioplasties, the patient is positioned supine w ith the head in a neutral position on either a gel donut or three -point xation.
• For bilateral hem icraniectom ies it m ay be necessary to do one side at a tim e, reprepping and redraping in bet ween.
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Techniques of Alloplastic Cranioplast y
Skin Incision Unilateral (Fig. 26.6)
Figure
Procedural Steps
Pearls
Fig. 26.6
The incision is made w ith a no. 10 blade from the superoanterior frontal region rst and opened in progressive fashion until the temporalis muscle is reached. The bone edge is palpated under the incision. If there is no bone edge, a straight clamp is used to separate the pericranium from the galea to provide protection from the knife blade w hen bone cannot be palpated underneath the incision. Care should be taken to open the scalp ap separately from temporalis muscle.
• Alternatively, one can open with a m onopolar electrocautery with a needle tip cautery.
The incision is made w ith a no. 10 blade from the sagittal suture dow n to the zygoma bilaterally.
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Subcutaneous Dissection (1) (Fig. 26.7)
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Figure
Procedural Steps
Pearls
Fig. 26.7
The incision is opened in stages starting w ith the frontal, superior portion, and w rapping around to the temporalis, placing galeal clamps w hen this layer has been properly separated. The plane betw een the pericranium and galea is developed w ith sharp dissection (Metzenbaum scissors or no. 15 blade scalpel). The scalp layer can be properly re ected forw ard by developing the plane betw een the vascularized pericranium and the galea.
• The galea–pericranial plane m ay also be developed •
with a no. 10 or no. 15 blade scalpel, or with m onopolar electrocautery. In cases where the pericranium was elevated with the scalp during the initial procedure, this layer is virtually unscarred and m ay be dissected bluntly, leaving the pericranium against the dura.
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Techniques of Alloplastic Cranioplast y
Subcutaneous Dissection (2) (Fig 26.8a, b)
a
Figure
Procedural Steps
Fig. 26.8
Once the entire scalp ap has been re ected it is retracted anteriorly w ith scalp hooks, 2-0 braided sutures, or skin clamps attached to rubber bands and clamps. This is demonstrated for (a) unilateral and (b) bifrontal openings. Hemostasis is meticulously achieved w ith mono - and bipolar cautery.
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b
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Techniques of Alloplastic Cranioplast y
Dissecting the Temporalis Muscle (Fig. 26.9a–d)
a
b
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c
d
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Figure
Procedural Steps
Pearls
Fig. 26.9
(a) The temporalis should be dissected from posterior bone edge w ith monopolar cautery and then re ected from the dural surface w ith the use of sharp dissection (b, c). (d) The temporalis is then retracted anteriorly w ith scalp hooks, 2-0 braided nylon sutures, or skin clamps attached to rubber bands and clamps depicted here w ith the bifrontal approach.
• If the bone ap is replaced over functional muscle •
tissue, the patient m ay experience m ovement restriction and discomfort during m astication. If signi cant m uscle atrophy is present along with the risk of disrupting cerebral cortex, it is advisable to abandon m uscle transposition.
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Techniques of Alloplastic Cranioplast y
Preparation of the Craniectomy Site (Fig. 26.10)
Figure
Procedural Steps
Pearls
Fig. 26.10
A combination of monopolar cautery and curettes may be used to re ect all of the soft tissue o of the bony edges to allow for a tight t.
• If there is protrusion of the brain through the defect during •
Any lacerations of the dura should be closed primarily. If there is a large dural defect, one may use pericranium or a dural substitute to close it (depicted in the unilateral approach).
surgery it can be controlled with head of bed elevation, m annitol, and/or m ild hyperventilation. If it persists, one m ay pass a brain needle into the ventricles using anatom ic landmarks or ultrasound guidance to allow for enough decompression to perform the cranioplast y.
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Implant Types (Fig. 26.11a–f)
a
b
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Techniques of Alloplastic Cranioplast y
c
d
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e
f
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Techniques of Alloplastic Cranioplast y
Implant Type
Pros
Cons
Fig. 26.11a
Porous polyethylene
High strength and stabilit y Radiolucent Excellent cosm esis Easily contoured May be molded in the eld Easily xated Custom and anatomic options Minimal surgical tim e for implantation
Price Custom implants require advance planning, usually 3D CT im aging (but noncustom anatom ic implants available)
Fig. 26.11b
PEEK (polyetheretherketone)
High strength and stabilit y Radiolucent Excellent cosmesis Easily contoured Easily xated Minim al surgical time for implantation
Price Custom im plants require advance planning, usually 3D im aging Can be contoured with a drill but not m olded in the eld
Fig. 26.11c
Titanium plate
High strength and stabilit y Excellent cosm esis Minim al surgical tim e for implantation
Price Custom implants require advance planning Radiopaque with artifact on im aging Cannot be contoured or m olded in the eld May require special xation set
Fig. 26.11d
Titanium m esh
High strength and stabilit y Easily contoured Easily xated
Radiopaque with artifact on imaging More time spent contouring and plating in the surgical eld.
Fig. 26.11e
Hydroxyapatite cem ent compound
Osteoinductive Radiolucent Excellent cosm esis Easily contoured Easily xated Less surgical tim e for implantation than PMMA No advance planning needed
Price May require m esh for strength, stabilit y, and contouring in larger areas
Fig. 26.11f
PMMA (polym ethylm ethacrylate)
Radiolucent May be contoured in the eld No advance planning needed
Long surgical tim e for set up and contouring, hypertherm ic reaction while solidifying requiring irrigation May require mesh for strength, stabilit y, and contouring in larger areas
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Repairing the Temporal Defect (Fig. 26.12)
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Figure
Procedural Steps
Fig. 26.12
Anatomic constructs may be placed atop a temporosphenoid defect to improve contour and minimize furrow ing of the temporal region.
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Techniques of Alloplastic Cranioplast y
Temporalis Transposition (Fig. 26.13)
Figure
Procedural Steps
Fig. 26.13
If preserved, the temporalis muscle is secured to the holes placed to re -create its “insertion” at the superior temporal line w ith 2-0 braided nylon sutures to complete its transposition.
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Closing
Special Considerations
• Hydrogen p eroxid e m ay be u sed at th e su rgeon’s discret ion
Th e pat ien t’s ow n bon e ap is th e ideal m aterial for a cran ioplast y; h ow ever, if th e bon e ap is lost to osteolysis or in fect ion , au tologou s bon e (sp lit th ickn ess or h ar vest from oth er p ar ts of th e body) is less ideal because of don or site m orbidit y an d sh ap ing problem s. As such , in th ese sit uat ion s, an alloplast ic cran ioplast y is an app rop riate solu t ion . Th e t yp e of cran ioplast y m ost often dep en ds on th e su rgeon’s preferen ce an d exp erien ce as w ell as costs an d availabilit y. Th e m ost frequ en tly u sed cran ioplast y m aterials are polym ethylm eth acr ylate (PMMA), hydroxyapat ite, t it an iu m , polyethylen eth erketon e (PEEK), an d porous polyethylen e. PMMA is th e m ost frequ en tly u sed allop last ic m aterial becau se of it s good biocom pat ibilit y an d low cost an d proven efcacy in th e long term .4 Alth ough it can be u sed at th e t im e of cran iotom y for im m ediate single st age cran ioplast y, th e in t raoperat ive t im e an d en ergy spen t con tou ring th e m aterial exceeds th at of oth er im p lan t s. In add it ion , it is d i cu lt to obt ain a cosm et ic resu lt th at ap proxim ates th at of th e cu stom im plan t s. Ut ilizing a cu stom design ed m esh w ith t h e PMMA im plan t w ith larger cran ial defect s m ay allow for th e opt im al cosm et ic im p lan t at a lesser exp en se th an oth er cu stom im plan t s.5 Hydroxyap at ite (HA) is probably th e m ost frequ en tly u sed ceram ic in cran ioplast y secon dar y to its h igh biocom pat ibilit y arising from osteoin tegrat ion .6 It set s u p faster, is easier to con tour, an d is isoth erm ic—all bene t s over PMMA.7 How ever, in am m ator y react ion s h ave been described in th e postoperat ive period. Furth erm ore, th e cost s of HA, especially if com bin ed w ith a custom m esh for larger im plan t s, m ay be exceed th at of custom im plan ts an d thu s be cost proh ibit ive. PEEK8 an d porous polyethylen e 9 are both biocom pat ible m aterials th at provide h igh st rength an d radiolu cen cy for postoperat ive im aging. Th e u se of custom design ed im plan t s for cran ioplast y is in creasing in calvarial recon st ruct ion , due to th e ease of use, st rength , an d excellen t cosm et ic results. Th ey can both be con toured in th e surgical eld an d easily xated. Furth erm ore, sh ou ld a postoperat ive in fect ion occur, th ey m ay be rem oved an d re-sterilized for later reim plan t at ion . Porous polyethylen e h as th e addit ion al advan tage of being able to be
• • • • •
for w ou n d clean sing an d h em ost asis. Th e w oun d is h eavily irrigated w ith salin e w ith or w ith out an t ibiot ics. A suction drainage device m ay be placed in th e subgaleal plane. Th e posterior port ion of th e tem poralis m u scle is reapproxim ated w ith 2-0 braid ed su t u res. Th e scalp is approxim ated w ith 3-0 braided absorbable su t u re in an inver ted, in terru pted fash ion . Th e skin is closed w ith 3-0 nylon in a vert ical m at t ress fash ion or w ith st aples.
Postoperative Management Monitoring • It is th e au th ors’ p ract ice to place th e p at ien t in a m on itored set t ing overn igh t in th e p ostoperat ive period to obser ve for seizu re act ivit y or eviden ce of in t racran ial bleeding.
Medication • Ph enytoin or levet iracetam is m ain tain ed at previou sly m en •
t ion ed levels for a total of 7 days. It is opt ion al to give t w o to th ree doses of prop hylact ic an t ibiot ics in th e im m ediate postop erat ive p eriod .
Radiographic Imaging • A postop erat ive CT scan m ay be obtain ed to evalu ate for su b dural collect ion s or oth er h em orrh age.
Further Management • Drain s are rem oved th e n ext p ostop erat ive day or soon er if •
th ey appear to be drain ing cerebrospin al u id. Skin su t u res or stap les are rem oved after 2 w eeks.
Fig. 26.14 Three-dimensional CT rendering of preoperative soft tissue defect and axial CT image of porous polyethylene pterional implant (arrow).
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26 resh aped w ith h ot salin e at th e t im e of su rger y,10 an d prem ade an atom ic con tou rs, sh eet s, an d blocks are available at a d ecreased cost com pared to custom im plan t s.11 Cu stom t itan iu m im plan t s o er a good ch oice for cran ioplast y based on th eir st rength , biocom pat ibilit y, h an dling ch aracteristics, an d su it abilit y for postoperat ive im aging tech n iques.12 How ever, th ey are m ore di cu lt to sh ap e in th e eld an d m ay requ ire sp ecial xat ion system s. In addit ion , th e t it an ium art ifact m ay be su bopt im al for th e follow -u p of m en ingiom a an d oth er t u m ors. An other con siderat ion after recon st ru ct ing th e calvarial defect is soft t issu e recon st ru ct ion over th e calvariu m /allop last ic cran ioplast y. Often w h en a decom pressive cran iectom y h as been perform ed, an d th e tem poralis m u scle u n dergoes w asting an d is n ever restored to it s previou s bulk, cau sing tem poral h allow ing. Both porou s p olyethylen e pterion al im p lan ts (Fig. 26.14) an d/or hydroxyap at ite cem en t m ay be u sed to augm en t th e tem poralis an d restore aesth et ics.7
References 1. Goodrich, JT. Cranioplast y. In: Albright AL, ed. Principles and Practice of Pediatric Neurosurgery. New York: Thiem e; 2008:864–877 2. San an A, Hain es SJ. Repairing h oles in th e h ead: a h istor y of cran ioplast y. Neu rosurger y 1997;40(3):588–603
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3. Ch im H, Sch an t z JT. New fron t iers in calvarial recon st r u ct ion : in tegrat ing com puter-assisted design an d t issue engin eering in cran ioplast y. Plast Recon st r Surg 2005;116(6):1726–1741 4. Moreira- Gon zalez A, Jackson IT, Miyaw aki T, et al. Clin ical ou tcom e in cran ioplast y: crit ical review in long-term follow -u p. J Cran iofac Su rg 2003;14(2):144–153 5. Lara WC, Sch w eit zer J, Lew is RP, et al. Tech n ical con siderat ion s in th e use of polym ethylm eth acr ylate in cranioplast y. J Long Term E Med Im plan t s 1998;8(1):43–53 6. Verheggen R, Merten HA. Correction of skull defects using hydroxyapatite cem ent (HAC)—evidence derived from anim al experim ents and clinical experience. Acta Neurochir 2001;143(9):919–926 7. Tadros M, Cost an t in o PD. Advan ces in cran iop last y: a sim p li ed algorith m to guide cran ial recon st ruct ion of acqu ired defect s. Facial Plast Su rg 2008;24(1):135–145 8. Hanasono MM, Goel N, DeMonte F. Calvarial reconstruction w ith polyetheretherketone im plants. Ann Plast Surg 2009;62(6):653–655 9. Lin AY, Kin sella CR, Rot tgers SA, et al. Cu stom p orou s p olyethylen e im plan t s for large-scale pediat ric skull recon st r uct ion : early ou tcom es. J Cran iofac Surg 2012;23(1):67–70 10. Liu JK, Got tfried ON, Cole CD, et al. Porous polyethylen e im plan t for cran ioplast y an d sku ll base recon st r u ct ion . Neu rosu rg Focu s 2004;16(3):ECP1 11. Wellisz T, Dough ert y W, Gross J. Cran iofacial applicat ion s for the Med por p orou s p olyethylen e exblock im p lan t . J Cran iofac Su rg 1992;3(2):101–107 12. Cabraja M, Klein M, Leh m an n TN. Long-term resu lt s follow ing t it an ium cran ioplast y of large sku ll defect s. Neurosurg Focus 2009;26(6):E10
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Surgery for Frontal Sinus Injuries Abilash Haridas and Peter J. Taub
Introduction Extern al force directed to th e an terior por t ion of th e foreh ead can result in injur y to th e front al sin us. Th e fron t al bon e is th e st rongest com p on en t of th e cran iofacial skeleton an d can w ith st an d bet w een 800 an d 2200 lb of force before fract u ring.1,2 Th e sin u s is rough ly pyram idal in sh ape an d often divided by a m idlin e or p aram idlin e sept u m of bon e. Th e sin us is absen t at birth , but begin s to act ively pn eum at ize bet w een 7 an d 8 years of age to reach an adult volum e after pubert y. By th eir m ech anism , m ost inju ries p rodu ce p osterior disp lacem en t of th e bon e in to th e fron t al sin us, alth ough bon e at th e periph er y of th e injur y can prot rude out w ard. Depen ding on th e force an d direct ion of th e injur y, fract ures can involve eith er th e an terior t able of th e sin us, both th e an terior an d posterior t ables, or solely th e p osterior table.
•
Indications
Sin ce th e et iology is t raum a, an d is often of sign i can t force, a fu ll t rau m a w orku p sh ou ld be p erform ed. In it ial con rm at ion th at th e air w ay is paten t , th e pat ien t is breath ing, an d th ere is adequ ate circu lat ion is p aram ou n t . Th e m ech an ism of fron t al sin u s fract u re p laces th e cer vical spin e at risk for inju r y. Carefu l p hysical exam in at ion of th e cer vical spin e as w ell as app ropriate im aging st udies is in dicated. Adequate plain lm s sh ou ld be obt ain ed an d CT added if th e in it ial lm s are eith er in adequate or in con clusive.
• Su rgical t reat m en t , if in dicated, sh ou ld be in st it u ted w ith in
•
•
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abscess. Som e au th ors elect to closely obser ve p at ien ts w ith a p osterior table fract u re an d associated leakage of cerebrosp in al u id (CSF) for a de n ed period of t im e, su ch as 7 days.1 For n on displaced posterior t able fract u res, th e m an agem en t is m ore con t roversial. Som e auth ors suggest th at all p osterior t able fract ures sh ould un dergo explorat ion an d be exam in ed directly via sin uscopy. Oth ers t reat th ese inju ries w ith close obser vat ion an d explore if com plicat ion s develop. Persisten t rh in orrh ea in dicates leakage of cerebrospin al u id du e to injur y to th e dura th at h as n ot h ealed w ith obser vat ion alon e an d requ ires in ter ven t ion . Secon dar y correct ion is in dicated for w ou n ds th at w ere ob ser ved in lieu of op erat ive in ter ven t ion an d h ave h ealed w ith n ot iceable deform it y.
th e rst 12 to 48 h ours after th e injur y, depen ding on th e overall h ealth of th e p at ien t . Early t reat m en t redu ces th e in ciden ce of long-term com plicat ion s.3,4 With resp ect to th e an terior t able, depressed fract u res th at w ill produce n ot iceable deform it y after th e resolut ion of edem a or th at cou ld poten t ially resu lt in m u cocele form at ion require repair. If th ere is n o com p uted tom ograp hy (CT) eviden ce of n asofron tal out ow t ract obst ruct ion (opaci ed sin u s, associated an terior eth m oid com plex fract u re, or fron tal sin u s oor fract u re), obser vat ion m ay be recom m en ded w ith less likelih ood of fut u re com p licat ion s developing.4 With resp ect to th e p osterior table, th e p resen ce of pn eu m oceph alu s h as been an in dicat ion for repair by som e auth ors.5 Th e pn eum oceph alus represen ts com m un icat ion bet w een th e sterile m en ingeal space an d th e extern al environ m en t , w h ich cou ld lead to poten t ially life-th reaten ing in t racran ial com plicat ion s, such as m en ingit is, en ceph alit is, an d brain
• •
Preprocedure Considerations
Radiographic Imaging • CT is th e gold st an dard im aging m odalit y for th e cran iom a xillofacial skeleton . Historically, plain lm s w ere obt ain ed, w h ich w ere able to iden t ify th e presen ce of uid in th e fron t al sin us, but presen ted di cult y w h en t r ying to determ in e th e presen ce of an terior, posterior, or th rough -an d-th rough injuries. CT scan s are able to provid e axial, coron al, an d sagitt al im ages th at can separately evaluate th e an terior an d posterior aspects of th e sin us (Figs. 27.1, 27.2, an d 27.3).
27
Fig. 27.1 CT demonstrating an isolated fracture of the anterior table of the frontal sinus.
Surgery for Front al Sinus Injuries
Fig. 27.2 CT demonstrating an isolated fracture (arrow) of the posterior table of the frontal sinus. Note the presence of pneumocephalus.
Fig. 27.3 CT demonstrating a fracture involving both the anterior and posterior tables of the frontal sinus.
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Operative Procedure Bicoronal Incision (Fig. 27.4)
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Figure
Procedural Steps
Fig. 27.4
A bicoronal incision several centimeters behind the hairline provides the best access for exposure of the anterior forehead and frontal sinus. The residual scar is inconspicuous if attempts to minimize alopecia are taken. Super cial electrocautery should be avoided. A stair-step incision is designed along the w ound to break up the w ound and prevent the hair, especially w hen w et, from falling all in one direction. A strip of hair over the area of the incision is shaved for exposure and to facilitate ultimate closure. The incision is in ltrated w ith 1%or 0.5%lidocaine w ith 1:100,000 or 1:200,000 epinephrine, respectively. After prep and drape, the incision is made w ith a scalpel blade in the direction of the hair follicles. The deeper subcutaneous tissues may be divided w ith electrocautery dow n to the level of the periosteum.
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Surgery for Front al Sinus Injuries
Subperiosteal Dissection (Fig. 27.5a, b)
a
b
Figure
Procedural Steps
Fig. 27.5
(a) Dissection superior to the fractured area may proceed in either a subgaleal or subperiosteal plane. How ever, once the fracture fragments are encountered, dissection in a subperiosteal plane is required to mobilize and reduce the fracture fragments. If the entire supraorbital rim needs to be visualized, the supraorbital nerves may need to be taken out of their foramina. This does not need to be done if the nerves merely rest w ithin a notch. (b) To easily convert each foramen into a notch, a 2-mm osteotome is placed inside the medial and lateral aspects of the foramen and directed inferiorly. Once the nerves are free, the soft tissues on the orbital rim and roof can be dissected in a subperiosteal plane for exposure.
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Fragment Removal and Cataloguing (Fig. 27.6)
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Figure
Procedural Steps
Pearls
Fig. 27.6
An elevating tool (Freer, bone hook, etc.) can be inserted betw een the fragments to reduce them into a more anatomic position or remove them for access to the sinus and posterior table.
• If the fragm ents are loose and exposure of deeper structures is required, the fragm ents should be labeled and catalogued so that they m ay be replaced in the correct position and alignm ent.
27
Surgery for Front al Sinus Injuries
Con rming Frontonasal Duct Patency (Fig. 27.7)
Figure
Procedural Steps
Fig. 27.7
Placing a clean cotton sw ab in each of the nostrils and instilling a dilute solution of methylene blue in saline via a syringe and catheter into each of the ducts can rapidly con rm frontonasal duct patency. Transmission of dye dow n the ducts, into the nose at the anterosuperior aspect of the middle meatus, and onto the cotton sw ab indicates patency.
Pearls
449
V Reconstructive Surgery
Removal of the Posterior Table, if necessary (Fig. 27.8)
450
Figure
Procedural Steps
Pearls
Fig. 27.8
In the presence of pneumocephalus or displacement of the posterior table fracture fragments, the entire posterior table can be removed, allow ing the sinus to be “cranialized” (see Fig 27.10).
• The bone fragm ents rem oved from the posterior table can then be used for autogenous graft m aterial to plug the frontonasal ducts. Alloplastic m aterial should be avoided. When possible, dural breaches should be repaired either prim arily or with a dural patch.
27
Surgery for Front al Sinus Injuries
Burring the Sinus Mucosa (Fig. 27.9)
Figure
Procedural Steps
Fig. 27.9
The sinus mucosa does not stretch at against the w all of the sinus but rather follow s small invaginations across the surface. Therefore, adequate removal of the mucosa requires obliteration of the super cial depressions in the bone w ith a pow er bur. Every surface and facet of the sinus should be debrided to remove the mucosa.
451
V Reconstructive Surgery
Packing the Frontonasal Ducts (Fig. 27.10)
452
Figure
Procedural Steps
Fig. 27.10
If the posterior table is removed and the sinus allow ed to cranialize, the frontonasal ducts must be obliterated to avoid an ascending infection from the nonsterile respiratory tract. Plugging of the ducts has been described using muscle, fat, or alloplastic material. How ever, morselized bone graft from the remnants of the posterior table provides excellent graft material. The bone is crushed w ith a rongeur on a back table and packed into the ducts.
27
Surgery for Front al Sinus Injuries
Elevation and Rotation of Pericranial Flap (Fig. 27.11a, b)
b
a
Figure
Procedural Steps
Fig. 27.11
(a) A ap of pericranial tissue provides further separation of the nasal mucosa and meningeal space. The ap is harvested from the deep surface of the bicoronal ap and based inferiorly along the supraorbital rim. (b) The pericranium should be elevated as large as possible to w rap over the inferior aspect of bone and dow n into the anterior fossa. It can be incised w ith the electrocautery and dissected free w ith a scissors.
453
V Reconstructive Surgery
Application of Fibrin Sealant (Fig. 27.12)
454
Figure
Procedural Steps
Fig. 27.12
Final separation is achieved w ith brin sealant placed over the pericranial ap.
27
Surgery for Front al Sinus Injuries
Replacement of Cranial Bone Flap Components (Fig. 27.13)
Figure
Procedural Steps
Pearls
Fig. 27.13
The anterior table fracture fragments can be reconstituted on a back table w ith plates and screw s made of either titanium or resorbable material. The entire construct is then replaced over the forehead and xated in the same manner.
• Low pro le plates are preferable since the bone is not weight bearing and any super cial irregularit y m ay be noticeable.
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V Reconstructive Surgery
Closing
Special Considerations
Cranial Incision
Persisten t leakage of u id from th e n ose m u st be evalu ated for CSF. An t ibiot ic prop hylaxis is con t roversial in fron tal sin u s t rau m a. On e recen t ret rosp ect ive st u dy by Devaiah et al sh ow ed n o ben e t w ith resp ect to th e rate of p ostop erat ive in fect ion s w ith addit ion al an t ibiot ics, but suggested th at an t ibiot ic usage m ay be w arran ted in th e presen ce of severe facial t raum a an d m u lt iple open fract ures.3,6 Alth ough sign i can t brain injur y m ay accom pany fron tal sin us injuries, th e use of steroids is n ot recom m en ded to redu ce in t racran ial p ressu re, an d, in fact , is con t rain dicated.7 Alth ough an em erging tech n iqu e, th e role of en doscopic repair h as been lim ited to con tou ring of m in im ally displaced an terior t able fract u res.1,8
• Th e w oun d is irrigated w ith copious w arm n orm al salin e • • • •
w ith or w ith out an t ibiot ics. A at su ct ion d rain is placed across th e ver tex of th e sku ll. Th e scalp is closed in layers. Depen ding on th e age of th e pat ien t , th e galea is reapproxim ated w ith in terrupted 3-0 ab sorbable su t u res. Th e skin is closed w ith run n ing locked 4-0 plain gut sut ures or altern at ive tech n iques, such as st aples. A dressing con sist ing of pet roleu m gau ze, in dividu al dr y gau ze, an d a h ead w rap is app lied.
Postoperative Management Th e pat ien t is kept in th e h ospital u n t il aw ake an d alert . Th e drain is kept to self-suct ion an d th e out put follow ed for quan t it y an d color. If it is n oted to be too sanguin eous, th e scalp sh ou ld be carefu lly in sp ected for eviden ce of h em atom a an d a seru m h em atocrit ch ecked. Eviden ce of ongoing bleed ing w arran ts ret urn to th e op erat ing room for evacu at ion an d h em ost asis. W h en drain age is m in im al, it m ay be rem oved.
Radiographic Imaging • Postop erat ive im aging w ith CT can be obt ain ed at th e discre•
•
456
t ion of th e surgeon . Pat ien t s sh ou ld be follow ed closely in t h e early p ostop erat ive p eriod for th e develop m en t of m en ingit is, en cep h alit is, brain abscess, osteom yelit is of th e fron t al bon e, n on u n ion , caver n ou s sin u s th rom bosis, CSF leak, m u copyocele, an d m en in goen cep h alocele. Mu coceles h ave an in sid iou s cou rse over m any years, w arran t ing long-term follow -u p w ith im aging.1,4
References 1. Man olid is S, Hollier LH Jr. Man agem en t of fron t al sin u s fract u res. Plast Recon st r Surg 2007;120(7 Suppl 2):32S–48S 2. Strong EB, Kellm an RM. Endoscopic repair of anterior table—frontal sinus fractures. Facial Plast Surg Clin North Am 2006;14(1):25–29 3. Bu llock MR, Ch esn u t R, Gh ajar J, et al. Su rgical m an agem en t of dep ressed cran ial fract u res. Neu rosu rger y 2006;58(3 Su p p l): S56–60; discussion Si-iv 4. Rodrigu ez ED, St anw ix MG, Nam AJ, et al. Tw en t y-six-year experien ce t reat ing fron t al sin us fract ures: a n ovel algorith m based on an atom ical fract ure pat tern an d failure of conven t ion al tech n iques. Plast Recon st r Surg 2008;122(6):1850–1866 5. Tedaldi M, Ram ieri V, Forest a E, et al. Exp erien ce in th e m an agem en t of fron t al sin u s fract u res. J Cran iofac Su rg 2010;21(1): 208–210 6. Lau der A, Jalisi S, Spiegel J, et al. An t ibiot ic prophylaxis in th e m an agem en t of com plex m idface and fron t al sin us t raum a. Lar yngoscope 2010;120(10):1940–1945 7. Brat ton SL, Ch est n u t RM, Gh ajar J, et al. Gu idelin es for th e m an agem en t of severe t raum at ic brain injur y. XV. Steroids. J Neurot raum a 2007;24(Suppl 1):S91–95 8. Rontal ML. State of the art in craniom axillofacial traum a: frontal sin us. Curr Opin Otolaryngol Head Neck Surg 2008;16(4):381–386
VI
Special Considerations in Pediatric Emergency Neurosurgery
28
Special Considerations in the Surgical Management of Pediatric Traumatic Brain Injury Anthony Figaji and P. David Adelson
Introduction Ch ildren an d adults are physiologically di eren t . Even w ith in th e pediat ric populat ion , th ere is a w ide range of physiological n orm at ive valu es across th e age sp ect ru m . Th is is p erh aps m ost relevan t in th e n eurosu rgical set t ing for th e m an agem en t of in t racran ial pressure (ICP) an d blood pressure. Path ophysiology after t rau m at ic brain inju r y (TBI) is also di eren t in ch ild ren . Di u se brain inju r y is m ore com m on . Focal inju r y an d ext raaxial h em atom as are less com m on . Th ere also are di eren ces in th e pressure–volum e relat ion sh ips w ith in th e skull, m et abolic resp on ses to inju r y, an d cerebral h em odyn am ics—all of w h ich h ave clin ical im p licat ion s for t reat m en t . Fu r th erm ore, th e tech n ical asp ect s of op erat ive m an agem en t in th e p ediat ric pop u lat ion —w ith regard to an esth et ic con t rol, operat ive plan n ing, an d t issu e h an dling—requ ire sp ecial con siderat ion . Alth ough it is beyon d th e scope of th is ch apter to cover all th e det ails of ever y sp eci c em ergen cy op erat ion perform ed in ch ildren , key p rin cip les com m on to th e m ost im por tan t of th ese procedures are addressed .
•
•
•
Indications • Insertio n o f parenchym al m o nito rs (ICP, brain oxygen , m i-
•
458
crodialysis, etc.). It is th e auth ors’ pract ice to place (at m in im u m ) an ICP m on itor for all p at ien t s w h o requ ire ven t ilat ion after TBI an d w h o h ave an abn orm al h ead com pu ted tom ograp hy (CT) scan . Invasive m on itoring m ay also be con sidered for pat ien t s w ith di u se inju ries, as a n orm al CT does n ot preclude a pat ien t from poten t ially h aving in t racran ial hyperten sion . In t racran ial m on itoring also m ay be con sidered for p at ien t s w ith oth er acute n eurologic path ologies th at result in com a an d th at m ay be associated w ith brain sw elling an d brain isch em ia. Open sut ures an d fon tan els in young ch ildren sh ou ld n ot discou rage m on itoring, as th ese pat ien t s rem ain at risk for in creased ICP. Insertio n o f ventricular drainage cathete rs. Extern al ven t ricular drain (EVD) placem en t en ables accurate m onitoring of ICP an d allow s for th erapeut ic drain age of cerebrospin al u id (CSF) in th e set t ing of in creased ICP. Ap prop riate in dicat ion s for EVD placem en t in clude a n eed for ICP m on itoring in pat ien t s w ith severe TBI (Glasgow Com a Scale [GCS] 8)
• •
an d th e presen ce of hydrocep h alu s. W h ile th ere is Class III eviden ce for u se of lu m bar d rain s w ith a con cu rren t EVD an d open cistern s on CT, it h as n ot been th e pract ice of th e auth ors to use such devices because of con cern of h ern iat ion . Operative treatm ent o f depressed skull fractures. Not all closed, depressed fract ures require surger y. Min or depression s often w ill rem old over t im e, esp ecially in th e you ng ch ild. In dicat ion s for operat ive repair in clude depressed fract ures associated w ith sign i can t m ass e ect—w ith or w ith out subadjacen t h em atom a; com poun d, depressed fract ures; an d fract u res in cosm et ically im p or t an t areas. Cran io to m y/cran ie cto m y fo r extra- o r in tra-axial h e m ato m as. Th e in d icat ion s for evacu at ion of in t racran ial h em atom as con form largely to t h e corresp on ding pr in cip les in ad u lt t rau m a. Hem atom as associated w it h sign i can t m ass e ect are rem oved . Con t u sion s are m ost su it able for rem oval if—in ad d it ion to d em on st rat in g m ass e ect —t h ey are d iscrete an d close to t h e cor t ical su rface. Hem atom as of t h e tem p oral lobe an d p osterior fossa p resen t t h e greatest r isk for sign i can t m ass e ect . Deco m pressive cranie cto m y. Th e in dicat ion s for decom p ressive cran iectom y are sim ilar to th ose in adult s. Th e exp ect at ion of clin ical ben e t from th e procedu re, h ow ever, m ay be greater in ch ildren th an in adu lt s. Cran iectom y, if con tem plated, sh ould be perform ed early rath er th an late—as a secon d t ier th erapy in th e m an agem en t of in creased ICP refractor y to m edical t reat m en t . Cranio plasty. Delayed cran ioplast y m ay be n ecessar y to rep lace th e bon e ap after decom pressive cran iectom y or to address oth er t rau m a-related cran ial defects. Re pair o f grow ing skull fractures. A grow ing sku ll fract u re, or leptom en ingeal cyst , is a poten t ial com plicat ion of skull fract u res in you ng ch ildren . Leptom en ingeal cysts u su ally st art to develop w ith in a few m on th s of th e inju r y. Pu lsat ion of th e brain again st an un recogn ized dural tear—w ith in terp osit ion of t issue bet w een th e edges of th e fract u re—leads to progressive w iden ing of th e fract ure an d in creasing size of th e du ral defect . Th e diagn osis becom es clin ically eviden t as a p rogressively en larging, p u lsat ile m ass in th e region of th e previou s fract ure. Sur veillan ce is w arran ted for all young ch ildren w ith skull fract ures. Clin ical follow -up at 2–4 w eeks p ost-injur y, w ith or w ith ou t fur th er radiograph ic im aging, is in dicated to assess for persisten t or in creasing sw elling in th e region of th e fract u re. If a grow ing fract u re is diagn osed, it requires op erat ive repair.
28
Special Considerations in the Surgical Managem ent of Pediatric Traum atic Brain Injury
Preprocedure Considerations
X-ray • Plain sku ll radiograph s are obt ain ed on ly on rare occasion .
Radiographic Imaging CT • CT scan s of th e h ead (6 cer vical spin e) sh ou ld be acquired
• •
•
as soon as th e ch ild is h em odyn am ically stable. Abdom in al or th oracic CT can be perform ed at th e sam e t im e for polyt raum a pat ien t s if th ere is a clin ical in d icat ion . Rou t in e u se of body scan s is n ot advocated for several reason s, in cluding th e in creased dose of radiat ion . Op en su barach n oid cistern s on a h ead CT do n ot in dicate n orm al ICP. Part icu lar at ten t ion sh ou ld be p aid to th e p osterior fossa on h ead CT. It is easy to m iss h em atom as h ere, an d th e con sequen ces m ay be severe, given th e relat ively com pact size an d im p or tan t an atom ical con ten t of th e com par t m en t . Brain stem com pression an d hydrocep h alu s are com m on com p licat ion s. Such h em atom as are often associated w ith a fract u re in th e occipital or suboccipital region an d m ay occur in conjun ct ion w ith a ven ous sin us injur y. Th e low est axial cut s sh ould be review ed for eviden ce of an ext ra-axial h em atom a ven t ral to th e low er brain stem . Hem atom a in th is locat ion m ay be a m arker for clival fract ure an d/ or a ligam en tous injur y at th e cran iocer vical jun ct ion .
•
•
Anesthetic Considerations in Children • It is essen t ial th at th e an esth esiology team h ave both p ediat-
•
MRI • Magn et ic reson an ce im aging (MRI) of th e brain is rarely in -
•
dicated in th e set t ing of acu te t raum a, w ith th e except ion of st u d ies perform ed to exclu de associated spin al or cran iocervical inju ries. Su sp icion of SCIWORA (spin al cord injur y w ith ou t rad iograp h ic abn orm alit y) requires an MRI of th e spin e.
a
A n orm al skull radiograph does n ot exclu de an in t racran ial injur y, an d a sku ll fract ure detected on radiograp hs does n ot n ecessarily in dicate an associated in t racran ial h em atom a; th erefore, sku ll radiograph s do n ot ch ange th e in dicat ion for h ead CT. Plain radiograp h s m ay h ave a role in th e follow -u p of fract ures in you ng ch ildren an d as part of th e bone su r vey in th e set t ing su spected n on acciden t al inju r y. Plain radiograph s of th e cer vical spin e are st ill used rout in ely for severe TBI pat ien ts, w ith the addit ion of MRI if ligam en tou s injur y or SCIWORA is suspected. Even in absence of suspected SCIWORA th ough , it is recom m en ded to practice basic spin al caut ion ar y m easures an d keep th e head in th e m idline posit ion for children w ho have a depressed level of con sciousness. Preoperat ive im aging (Fig. 28.1a, b).
•
ric an d p olyt rau m a exp erien ce. Secon dar y in su lt s con t ribu te su bstan t ially to w orse ou tcom e an d so sh ou ld be aggressively avoided. In adequ ate m an agem en t of th e resp irator y an d circu lator y system s m ay lead to secon dar y in su lt s su ch as hyp oxia an d hypoten sion . Brain sw elling m ay be exacerbated by hypo- or hyperten sion , hypercarbia, an d in adequate pain con t rol. Th e en dot rach eal t u be m ust be fasten ed securely, part icu larly if th e ch ild’s h ead is to be t urn ed. Loss of th e air w ay is of greater con sequen ce in ch ildren because th ey deteriorate rap idly. Th e TBI pat ien t , in p art icu lar, h as a redu ced capacit y to tolerate hypoxic in sults. Hypocarbia m ay exacerbate th e
b
Fig. 28.1a, b Axial CT (a) bone and (b) soft tissue windows demonstrating a bony defect with protrusion of meninges. This patient fell from a bed, striking his head on the concrete oor, and presented approximately 8 months later with a tender, pulsatile postauricular mass.
459
VI Special Considerations in Pediatric Em ergency Neurosurgery
• •
• •
•
•
•
decreased cerebral blood ow often seen early after TBI, an d hypercarbia m ay in crease cerebral blood volum e an d, con sequen tly, ICP. In du ct ion of an esth esia m u st be sm ooth ; cough ing or bu cking m ay h ave fat al con sequ en ces in pat ien t s w h o already h ave life-th reaten ing increased ICP. Often , an esth esiologists are accu stom ed to m ain t ain ing p at ien t s at blood pressures in th e low er range of n orm al during elect ive su rger y. Th is pract ice m ay be h azardou s w h en m an aging th e TBI ch ild at risk of early brain isch em ia. Also, im p airm en t of p ressure autoregulat ion m ay resu lt in reduced capacit y to accom m odate a blood pressure in th e low er range of n orm al. Large bore in t raven ou s access allow s adequate respon se to h em odyn am ic in st abilit y, especially w h en th ere m ay be occu lt abdom in al or th oracic inju r y. To estim ate w hat blood pressure is adequate, the anesthesiologist m ust have access to ch arts for n orm al m ean arterial pressure ranges for age (and, preferably, h eigh t and gender as w ell). If a cran iotom y or cran iectom y is p lan n ed, en su re th at blood is cross-m atch ed for possible t ran sfusion , especially in th e ver y you ng. Th e circu lat ing blood volu m e of a ch ild is on ly 70–85 m L/kg depen ding on age, so relat ively sm all volum es of blood loss in th ese pat ien ts m ay rapidly lead to h em odyn am ic in st abilit y. Placem en t of cen t ral ven ou s an d arterial lin es is recom m en ded for severe TBI p at ien ts, n ot on ly for adequ ate in t raop erat ive h em odyn am ic con t rol, but also to facilitate in ten sive care u n it m an agem en t th ereafter. If m an n itol is requ ired in t raop erat ively to assist th e redu ct ion of brain sw elling, th e an esth esiologist m ust en sure th at th e pat ien t rem ain s euvolem ic th rough ou t an d th at th ere is an adequ ate resp on se to th e m an n itol in fu sion by m on itoring u rin e ou t put . Do n ot u se hypoton ic or glu cose-con t ain ing u ids.
Operative Management An exh aust ive descript ion of th e full range of em ergen cy procedures perform ed in pediat ric pat ien t s presen t ing w ith TBI w ou ld exceed th e scop e of th is p u blicat ion . Th erefore, w e review som e basic prin ciples th at d ist ingu ish th e su rgical ap proach to pediat ric pat ien t s an d o er operat ive pearls relevan t to speci c procedures. Fin ally, w e provide m ore detailed guid an ce regarding th e rep air of grow ing sku ll fract u res—an en t it y th at is un ique to th e pediat ric populat ion .
General Surgical Principles • Take care w h en incising skin overlying open fon t an els an d •
•
•
su t u res. Con t rol bleeding from th e scalp ap early w ith th e applicat ion of scalp clips. Con t in ued ooze during th e operat ion can lead to sign i can t blood loss in young ch ildren . On ce th e scalp ap h as been t u rn ed, rem em ber to ch eck in term it ten tly th at th e ap rem ain s dr y th rough ou t th e operat ion . Th e skin an d scalp of young ch ildren is th in n er th an in adult s. Treat th e t issues gen tly an d do n ot cru sh th em bet w een pick-ups. Avoid acute ben ds in th e re ected scalp ap as th is m ay cu t o its blood su p p ly. Th is p oses a greater risk th an in adu lt s becau se th e scalp ap is th in n er an d th e blood p ressu re is low er. Th e du ra is often adh eren t w h ere cran ial su t ures are st ill open . Use a dissector to separate th e dura from th e bon e carefu lly an d th orough ly ben eath su t u re lin es.
ICP and Other Parenchymal Brain Monitors • ICP an d oth er invasive p robes (e.g., brain t issu e oxygen ) m ay
Operative Field Preparation • The child is positioned according to the t ype of procedure • • • • • • • • •
460
planned. If the spine has not been cleared, pay careful attention to protecting the cervical spin e w hile positioning for surgery. An t ist aphylococcal an t ibiot ics are given rou t in ely at th e t im e of skin in cision . Th e h ead of th e operat ive t able is sligh tly elevated to prom ote ven ou s ret u rn . Blood pressure sh ould be w ell m ain tain ed th rough out surger y. At n o t im e sh ou ld th e blood p ressu re be allow ed to d rop . If brain sw elling an d in creased ICP are su sp ected, a dose of m an n itol can be given ju st after in du ct ion . En sure th at th e plan n ed skin ap allow s adequate access for th e path ology con cern ed. As a gen eral prin ciple of t raum a su rger y, a w ider exp osu re is preferred . Prepare th e skin w idely to allow for an in crease in th e exposu re sh ou ld th is becom e n ecessar y du ring th e operat ion . Th e plan n ed skin in cision is in lt rated w ith 0.25%local an esth et ic an d epin eph rin e 1:400,000. Drap e an d p osit ion th e pat ien t so th at th e an esth esiologist h as adequ ate access to th e air w ay. Th e surgeon sh ould h ave a clear view of th e an esth esiology m on itors d u ring th e operat ion .
• •
•
be in t roduced via single or double lum en bolt s or in serted via a sm all bu r h ole an d t u n n elled to exit th e skin . Bolt system s can be u sed even in ver y young ch ildren ; m easure th e th ickn ess of th e skull from th e h ead CT an d plan in ser t ion accordingly. Un less th ere is a com pelling reason to do oth er w ise, m on itors are p laced in th e fron tal region on th e n on dom in an t side. For probes th at require accurate placem en t in w h ite m at ter (e.g., brain oxygen m on itors), m easurem en t s can be m ade from th e h ead CT. In p ract ice, p lacem en t of th e probe t ip 2.5 cm ben eath th e cort ical surface is usu ally adequ ate. Con siderat ion sh ould be given to th e locat ion of any invasive probes (an d th e scalp in cision used) relat ive to th e possibilit y th at th e ch ild m ay n eed furth er surger y.
External Ventricular Drains • Typically, an EVD is placed in a st an dard fron tal locat ion on •
th e n on dom in an t side, th rough a precoron al bur h ole in th e m idp u p illar y lin e. Th e cath eter is passed w ith a t rajector y th at is angled tow ard th e ipsilateral in n er can th us in th e coron al plan e an d just an terior to th e ipsilateral extern al auditor y m eat us in th e sagittal plan e.
28
Special Considerations in the Surgical Managem ent of Pediatric Traum atic Brain Injury
• Th e cath eter sh ould be passed slow ly, an t icipat ing th e t act ile
• Epidural h em atom as overlying a ven ous sin us presen t a
feedback w h en th e ep en dym a of th e ven t ricle is p en et rated. If th e ven t ricle is n ot en tered w ith th e rst p ass, a sligh tly m ore m ed ial t rajector y m ay be at tem pted . No m ore th an th ree p asses sh ou ld be at tem pted . TBI-related brain sw elling in ch ildren m ay resu lt in com p ression of th e lateral ven t ricle; h ow ever, w ith experien ce, th e ven t ricle st ill can be can n ulated in m ost cases. If n euron avigat ion is available, in t rodu ct ion of th e n avigat ion p robe th rough th e lu m en of th e ven t ricu lar cath eter m ay assist accu rate p lacem en t in di cu lt cases. An t ibiot ic-im pregn ated cath eters an d periprocedural an t ibiot ics are opt ion s th at m ay reduce th e in ciden ce of ven t ricu lostom y-related in fect ion s.
p ar t icu lar h azard in ch ildren due to th e poten t ial for rapid blood loss in th e set t ing of an already sm all tot al blood volu m e. If th e h em atom a m ust be evacuated, prepare for blood loss from th e sin us an d m on itor for possible air em boli. Plan a skin an d bon e ap th at allow s for ad equ ate exp osu re an d con t rol of th e sin us both proxim ally an d distally. If a sin us tear is iden t i ed, th is m ust be con t rolled w ith im m ediate p ressure over th e sin us to stem bleeding, sur veillan ce for air em boli, an d repair of th e sin u s u sing a pericran ial patch graft . If bleeding is too vigorou s to allow ad equ ate visu alizat ion , m ain t ain pressure over th e tear an d tem porarily con t rol th e sin us proxim ally an d distally to en able sut uring of th e p atch . Main t ain a paten t sin us to preven t add it ion al ven ou s engorgem en t of th e brain .
• • •
•
Craniotomy • Th e skin in cision sh ould be plan n ed based on th e locat ion of • • •
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th e lesion . Typically, for a un ilateral lesion , an ipsilateral quest ion m ark or T-sh aped in cision is perform ed to en able w ide access to th e h em isph ere. In gen eral, aim for as large a ap as p ossible. Th e base of th e skin ap sh ou ld be broad en ough to en su re adequ ate perfusion to th e skin . W h en th e ap is t urn ed, w rap an d t u ck an an t ibiot ic-soaked sw ab or cot ton sp onge ben eath th e ap to preven t th e creat ion of an acu te angle th at m igh t com p rom ise perfu sion to th e ap. Th is m ay be a par t icular problem in ver y you ng ch ildren . In term it ten tly m oisten th e sponge during th e p roced ure. Dissect th e ap in a su bgaleal p lan e to p rep are a free bon e ap. Preser ve th e p ericran iu m as th is can be u sed later for a dural graft if n eeded. Th e exten t of th e bony open ing is plan n ed according to th e u n derlying lesion . If th ere is gen eralized sw elling, th e bon e sh ou ld be rem oved dow n to th e tem p oral base to m axim ize th e space ach ieved at th e level of th e ten torial hiat us. If du ral op en ing is n ecessar y to evacu ate a h em atom a, a cru ciate in cision is perform ed over th e h em isph ere. Any su bdural h em atom a th en m ay be evacu ated. If evacu at ion of a con t u sion is p lan n ed, carefu l preoperat ive plan n ing or n euron avigat ion is required to opt im ize th e locat ion of th e cort icectom y. Often a subdu ral h em atom a is associated w ith a “bu rst” lobe in w h ich th e con t u sion can be iden t i ed at th e surface. A discrete h em atom a can be evacu ated aggressively. A con t u sion m ixed w ith brain t issu e sh ou ld be h an dled w ith greater cau t ion , d ep en ding on several factors, in clu ding th e eloqu en ce of th e involved brain an d th e degree of brain sw elling. Th e con ser vat ive approach of allow ing th e con t u sion /h em atom a to decom p ress it self m ay be all th at is required. If th e brain is sw ollen , th e du ra sh ou ld be exp an ded w ith a dural graft h ar vested from local pericran ium . Use n on absorb able su t u res an d close th e du ra in a w atert igh t fash ion . Th e decision of w h eth er to replace th e bon e ap depen ds on th e preoperat ive im aging, in t raoperat ive n dings, an d an t icip ated postop erat ive risk for ongoing in creased ICP. If th e bon e ap is left ou t , it sh ou ld be m an aged as below for decom pressive cran iectom y.
Surgery for Depressed Fractures • Th e prin ciples of depressed fract ure m an agem en t in ch ildren •
•
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are sim ilar to th ose of ad u lt s, w ith a few except ion s. If th e depressed fract u re is closed, th e skin in cision is p lan n ed based on th e locat ion of th e depressed fragm en t , blood sup p ly to th e ap, an d cosm esis. If th e fract ure is com pou n d, th e w oun d m ust be debrided an d exten ded in a cu r vilin ear, S-sh ap e to exp ose th e exten t of th e fract u re. Bon e is m u ch th in n er an d softer in ch ildren . Often a pingp ong t ype fract ure can be elevated by drilling a bu r h ole to th e side of th e fract ure an d by posit ion ing a sligh tly angled in st rum en t (e.g., a n o. 3 Pen eld or sm all periosteal elevator) th rough th e bur h ole, elevat ing th e fract ure from in side. If th e du ra is torn , a bu r h ole sh ou ld be placed at th e m argin of th e depressed fract ure—over in t act dura. Th en th e cran iectom y, or cran iotom y, can be perform ed to u n cover th e area of dural violat ion . Th e dural tear is sut ured, an d bon e fragm en t s, if clean , m ay be laid over th e defect . Bony defect s in ch ild ren u su ally h eal ver y w ell w ith n ew bon e grow th , as long as th e du ra is in t act . Larger lesion s m ay require later cran ioplast y if adequate rem odeling does n ot occur an d th e resu lt is a sign i can t cosm et ic an d/or fun ct ion al defect . Th e u se of autologous bon e is opt im al. Th e best bon e is split calvarial bon e, preferably t aken from th e correspon ding locat ion on th e opposite side. Th e h ar vested bon e can be split th rough th e diploic space, creat ing t w o p ieces: on e for th e defect an d th e oth er to be rep laced at th e d on or site. In you ng ch ildren , th is m ay n ot be possible. Rib graft or cran ioplast ic m aterial—resorbable or n on resorbable, p refabricated or n ot (i.e., m ethylm eth acr ylate)—m ay also be con sidered. Du ral d efects m u st alw ays be rep aired to avoid th e p oten t ial com plicat ion s of a CSF leak an d/or a grow ing skull fract ure. Devit alized skin m u st be d ebr id ed an d t h e w ou n d t h orough ly ir r igated . If t h e skin can n ot be closed p rim ar ily, t h e h elp of a p last ic su rgeon m ay be valu able to p lan a rot ated skin ap .
Decompressive Craniectomy • Several di eren t ap p roach es h ave been d escribed for decom p ressive cran iectom y (DC). Th e follow ing re ects a com bin at ion of gen eral prin ciples an d person al pract ice.
461
VI Special Considerations in Pediatric Em ergency Neurosurgery • Th e m ost im port an t surgical prin ciples of DC are: select a
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•
462
u n ilateral or bilateral app roach as approp riate, m ake th e cran iectom y as large as possible, an d con t rol th e brain sw elling before open ing th e dura. Th e ch oice of a bifron t al or h em icran iectom y depen ds both on person al preferen ce an d th e n at ure of th e injur y. Predom in an tly un ilateral h em isph eric injur y m ay be bet ter su ited to h em icran iectom y, w h ereas di u se inju r y or fron tal con t usion s m ay be bet ter suited to bifron t al cran iectom y. Th ough th e speci cs of each tech n ique di er, th e prin ciples of decom pression are th e sam e. Du rap last y in creases th e com p licat ion s associated w ith cran iectom y; h ow ever, open ing an d expan ding th e dura leads to su bst an t ially low er ICP, an d com p licat ion s are gen erally avoidable if don e correctly. Th e h em icran iectom y is perform ed sim ilar to th e h em isph eric cran iotom y. Maxim izing th e bony open ing h elps m in im ize th e degree to w h ich th e sw ollen brain push es again st th e bony lim it s. Pressure at th e bony edges m ay fu rther injure th e sw ollen brain an d con st rict ven ou s out ow of th at segm en t . Th e tem poral bon e is rem oved as low as possible d ow n to th e base to m axim ize th e decom pression at th e level of th e ten torial in cisura. Th e du ra is open ed an d expan ded w ith a large pericran ial graft , th e edges of w h ich can be sut ured so th at th ey lie w ith in th e dural edge, to m in im ize th e risk of th e sh arp du ral edge cu t t ing in to th e sw ollen brain . Th e bifron tal cran iectom y is perform ed th rough a bicoron al skin in cision , posit ion ed beh in d th e h airlin e. Th e scalp is re ected an teriorly, preser ving th e pericran ium for a dural graft . Keyh ole an d p aram edian bu r h oles lateral to th e sagittal sin us are used to create a large bifron tal, single-piece bon e ap exten ding posteriorly to th e coron al su t u re. Pay part icu lar at ten t ion w h en separat ing th e dura from th e bon e, esp ecially over th e m idlin e, to avoid injur y to th e sagit t al sinu s an d it s bridging vein s. Th e du ra is in cised in a U-sh ap e from lateral to m edial. Th e m idlin e sagit tal sin us is t ied o at th e fron t al base an d th e falx is sect ion ed from an terior to p osterior along th e skull base to allow for m a xim al expan sion
•
of th e brain . W h en doing th is, t ake care to preser ve cort ical vein s, esp ecially bridging vein s leading to th e sagit tal sin u s. Th e h ar vested pericran ial graft is used to expan d th e dura. Regardless of approach , it is of ut m ost im port an ce th at th e dura n ot be open ed abruptly if ten se to th e tou ch . Oth er w ise, m assive brain sw elling m ay p rodu ce rap id , u n con t rolled h ern iat ion of th e brain th rough th e du ral op en ing w ith resu lt an t com pression of super cial drain ing vein s an d progressive en gorgem en t of th e en t rapp ed brain . Alth ough , by de n it ion , th e pat ien t is in surger y for refractor y in t racran ial hyper ten sion , it is n early alw ays p ossible to con t rol th e sw elling for th e sh ort period of t im e it t akes to open th e du ra an d secu re th e graft in p lace. Th e su rgeon m u st w ork w ith th e an esth esiologist to m axim ize brain relaxat ion by th e t im e of du ral op en ing. Poten t ial in ter ven t ion s in clude con t rolling blood pressu re, adm in istering m an n itol an d/or hyp erton ic salin e at th e t im e of skin in cision , elevat ing th e h ead of th e bed, an d low ering th e ar terial CO2 (w h ile in creasing th e FiO2 ). Th e pericran ial graft m u st be p rep ared p rior to th e du ral open ing. W h en pressu re m an agem en t h as been opt im ized, th e du ra sh ould be open ed quickly an d th e graft in corporated w ith sut ure.
Repair of Grow ing Skull Fractures (Leptomeningeal Cyst) • Th ough n ot requiring em ergen t in ter ven t ion , grow ing skull • •
•
fract u res do rep resen t a late con sequ en ce of t rau m a an d, as su ch , deser ve m en t ion h ere. Opt im al t reat m en t of a grow ing sku ll fract u re requ ires u n derst an ding of th e path ology (see In dicat ion s). Th e du ra is alw ays torn ; th is tear w iden s w ith t im e as th e bon e edges separate. Usually th e dural edges ret ract w ell beyon d th e bon e edge so th at th e du ral defect is larger th an th e bony defect . Th e a ected pat ien t s are young, so th ere m ust be adequ ate preparat ion for blood loss. Do n ot un derest im ate th e poten t ial for blood loss in th ese operat ion s.
28
Special Considerations in the Surgical Managem ent of Pediatric Traum atic Brain Injury
Operative Procedure Repair of Grow ing Skull Fractures Positioning (Fig. 28.2)
Figure
Procedural Steps
Fig. 28.2
Positioning w ill be dictated by the anticipated need for anatomic access.
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VI Special Considerations in Pediatric Em ergency Neurosurgery
Incision (Fig. 28.3)
464
Figure
Procedural Steps
Pearls
Fig. 28.3
A curvilinear, S-shaped, or U-shaped incision is made to access the cranial defect.
• The extent of necessary exposure is planned from the CT head ndings and palpation of the edges of the defect.
28
Special Considerations in the Surgical Managem ent of Pediatric Traum atic Brain Injury
Subcutaneous Dissection (Fig. 28.4a, b)
a
b
Figure
Procedural Steps
Fig. 28.4
(a) Subgaleal dissection of the scalp ap is used to expose the full extent of the defect. (b) The periosteum is incised, follow ing the edges of the cranial defect. The periosteum is re ected inw ard, tow ard the defect. Using a sharp periosteal dissector, the periosteum–dura junction is freed circumferentially from the edges of the bone margin.
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VI Special Considerations in Pediatric Em ergency Neurosurgery
Craniotomy (Fig. 28.5a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 28.5
(a) Several bur holes are placed at the periphery of the bony defect, overlying normal dura. The exact position of the bur holes in relation to the defect depends on the anticipated dural retraction beneath the bone edges. Typically, larger lesions are associated w ith greater retraction of the dura beneath the bone edges. Preserve the periosteum overlying the bone to use as a dural graft.
• The m argin should be several centim eters
(b) A dissector is introduced through each bur hole and used to separate the dura from the overlying bone. A craniotome then is used to connect the bur holes, creating a “ring” bone ap (including the defect) that, in turn, is elevated aw ay from the underlying dura.
466
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from the edge of the bony defect or approxim ately 50% of the width of the defect, to create a bone ap that can be used to cover the defect. Prior MRI m ay give the surgeon an approxim ation of this distance; however, often it is the surgeon’s judgm ent based on the size of the defect. The dural edges are adherent to the underlying gliotic brain and m ust be separated from it circum ferentially.
28
Special Considerations in the Surgical Managem ent of Pediatric Traum atic Brain Injury
Closure of the Dural Defect (Fig. 28.6)
Figure
Procedural Steps
Fig. 28.6
A periosteal graft from normal bone is harvested to close the dural defect. The graft is incorporated circumferentially w ith 4-0 braided nylon stitches.
Pearls
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VI Special Considerations in Pediatric Em ergency Neurosurgery
Repair of the Bony Defect (Fig. 28.7a, b)
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b
468
Figure
Procedural Steps
Pearls
Fig. 28.7
(a) The harvested bone ap can be divided into tw o halves. If possible, each half then can be split w ith an osteotome (though the diploic space) into inner and outer tables, yielding a total of four pieces that may be used to cover the defect. (b) The bone graft is secured to the surrounding bone using resorbable or permanent mini plates. If the bone can be secured w ith sutures, this is preferable. Alternatively, mini plates are used.
• If the dural defect has been closed adequately, any residual bony defect will usually close over tim e.
28
Special Considerations in the Surgical Managem ent of Pediatric Traum atic Brain Injury
Closing • If th e bon e is replaced, it is secu red w ith absorbable or n on -
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•
absorbable p lates an d screw s. Th e size of th e screw s sh ou ld be m atched to th e th ickn ess of th e bon e. Long screw s risk p erforat ion of th e d ura. On th e oth er h an d, screw s m u st be of a su cien t length to ach ieve adequ ate bony pu rch ase. If th e bon e is left ou t , it sh ou ld be h an dled an d p rocessed for freezing in accordan ce w ith th e in st it u t ion’s bon e ban k protocol. Altern at ively, th e bon e can be placed in a subcut an eous abdom in al pocket . Th e follow ing caveats ap ply: com orbid ab dom in al t raum a m ay preclude access to th is site; it m ay be di cult to create an adequate pocket in a you ng ch ild; an d, if a bifron t al ap h as been elevated, it m ay be n ecessar y to sp lit th e bon e dow n th e m idlin e an d superim pose th e h alves to create th e opt im al con tour th at w ill t in th e pocket . Th e skin is closed w ith a 4-0 m on o lam en t sut ure or st aples.
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Postoperative Management Monitoring
Further Management • Con cern s about ongoing injur y to th e unprotected brain h ave
• Invasive ICP m on itoring is u su ally rou t in e in ch ildren w ith
•
•
severe TBI. Ben ign h ead CT feat u res do n ot exclu de in creased ICP or th e risk th at ICP w ill in crease in th e su bsequ en t days. ICP m on itoring is st an dard at th e au th ors’ in st it u t ion for any ch ild requiring ongoing ven t ilat ion , w ith out im m ediate plan s for ext u bat ion , after TBI. Th e m on itoring of brain t issue oxygen an d oth er m easures of cerebral h em odyn am ics or m et abolism is less w ell est ab lish ed in ch ildren th an in adult s, but is in creasingly com m on in clin ical p ract ice an d research . Typically, ICP is m ore fragile, or brit tle, in ch ildren th an in adu lt s. Becau se th ese obser ved dyn am ic ch anges are largely h em odyn am ic in n at u re, invasive m on itoring of blood p ressu re an d volu m e st at u s m ay allow for bet ter ch aracterizat ion of th e path ophysiology in in dividual pat ien t s, an d, in so doing, perm it m ore targeted t reat m en t of elevat ion s in ICP.
w as p erform ed ver y early after t rau m a (e.g., w ith in th e rst 2 h ou rs), repeat im aging m ay be in dicated to detect h em atom as th at w ere n ot dem on st rated in it ially. W h en th ere is a h em atom a on th e in it ial scan th at is t reated n on op erat ively, rep eat im aging m ay be n ecessar y to en su re th at th e h em atom a h as n ot en larged. For lesion s w ith m ass e ect in th e p osterior fossa, repeat im aging m ay be requ ired to exclu de th e developm en t of hydroceph alu s. Also, if th e pat ien t is m an aged w ith ou t in t racran ial m on itoring, th ere is a low er th resh old for repeat ing im aging. A planned follow -up head CT m ay be considered to look for optim al position of intracranial m onitors, evolution of hem atom as/ contusions, and brain swelling. At our institution, this is done 24–48 hours after adm ission, depending on stabilit y of the intracranial variables and nature of the initial scan. Decisions are individualized; however, in general, earlier scans are indicated w hen there is greater concern about the initial im aging ndings and w hen there are signi cant perturbations in ICP or brain oxygen. Postoperat ive im aging (Fig. 28.8).
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driven th e t ren d tow ard early replacem en t of bon e aps after cran iectom y. Reim plan t at ion m ay be appropriate w ith in 4 w eeks of th e in it ial surger y, provided th e brain sw elling h as su bsided, th e w ou n d is h ealed, an d th e p at ien t is free of in fect ion . How ever, th e t im ing of reim p lan t at ion sh ou ld n ot be accelerated if con dit ion s are su bopt im al, as bon e ap sep sis can create subst an t ial problem s. Th e bon e m ust n ot be au toclaved. It is rem oved from sealed bags an d allow ed to soak in a diluted solut ion of betadin e at th e st ar t of surger y. Th e pat ien t’s bon e is alw ays preferred to ar t i cial subst it utes, n ot on ly becau se of th e bet ter t bu t also becau se ad dit ion al grow th of th e sku ll is exp ected in you nger ch ildren . Ver y you ng ch ildren m ay be at in creased risk for bon e ap resorpt ion problem s.
Wound Management • Su bgaleal drain s m ay be u sed in th e im m ediate postoperat ive •
p eriod but sh ould be rem oved w ith in 12 h ou rs, if possible, or w h en th e drain age is below 25 m L per 12–24 h ours. Com pression , cot ton w rap –t ype dressings used for w oun d h em ost asis p ostop erat ively m ay requ ire loosen ing or cu t t ing.
Radiographic Imaging • As a gen eral prin ciple, th e frequen cy of CT im aging of ch il-
•
dren sh ould be lim ited because of th e long-term risk of radiat ion . Un n ecessar y follow -up im aging also exposes th e ch ild w ith severe injur y to poten t ial secon dar y in sult s associated w ith t ran spor t out of th e in ten sive care un it environ m en t . How ever, if in dicated, ap p rop riate im aging m ay be lifesaving. Th ere sh ou ld alw ays be a clear in dicat ion for rep eat im aging, su ch as clin ical deteriorat ion . W h en th e in it ial scan
Fig. 28.8 Axial CT im age demonstrating repair of the dural tear and bony defect.
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29
Special Considerations in Pediatric Cervical Spine Injury Paul Klim o Jr., Nelson Ast ur Neto, W illiam C. W arner Jr., and Michael S. Muhlbauer
Introduction Sp in e t rau m a in th e p ediat ric pop u lat ion is a relat ively u n com m on occu rren ce (1–2% of all p ediat ric fract u res 1 ), but h as been obser ved m ore frequen tly w ith im provem en t s in em ergen cy care, t ran spor t ser vices, an d t raum a life support .2 Ch ildren differ from th eir adu lt cou n terp ar t s w ith regard to spin e an atom y, p hysiology, an d body propor t ion s: • Ligam en ts an d join ts can st retch an d expan d con siderably w ith out tearing • Facet join t s are sh allow an d h orizon t ally orien ted • Vertebral bodies are w edged an teriorly • Un cin ate processes, w h ich lim it rotat ion , do n ot form u nt il age 10 • Disp rop or t ion ately larger h ead in conju n ct ion w ith w eaker an d in com p letely d evelop ed m u scu lar an d ligam en tou s su p p or t ing st ru ct ures Th ese u n ique di eren ces resu lt in a spin e th at is m ore m alleable th an th at of an adult . Pediat ric cer vical spin al injuries follow a p redict able pat tern related to th e ch ild’s age. Sp in al in ju ries in ch ildren younger th an 8–10 years of age are m ore likely to involve th e upper cer vical spin e, from th e occiput to th e th ird cer vical ver tebra. Most injuries in th is age group are ligam en tous axis-atlan to-occipit al dislocat ion s or spin al cord injuries w ith ou t radiograph ic abn orm alit y (SCIWORA). Ch ildren older th an 8–10 years of age are m ore vuln erable to cer vical spin e inju ries involving th e low er segm en t s (C3–C7); th e pat tern of inju r y in th is group is sim ilar to th e adu lt popu lat ion .3,4 Sp in al cord inju r y (SCI) is a rare occu rren ce in th e pediat ric p op u lat ion an d accou n t s for less th an 4% of th e tot al an n u al in ciden ce of SCI (Nat ion al Spin al Cord Inju r y St at ist ical Cen ter, 2004). Neurologic recover y in ch ildren w ith SCI ten ds to be bet ter th an in adult s.5 SCI occurring before th e adolescen t grow th sp u rt is a great risk factor for th e developm en t of p ost t rau m at ic scoliosis.5
Indications Pediat ric cer vical spin e inju ries can be divided in to inju ries th at a ect th e u p p er cer vical sp in e (occip u t–C2) an d th ose th at affect th e su baxial sp in e (C3–C7). Below is a list of th e inju ries th at are m ore com m on ly en coun tered in children . As st ated p reviou sly, older ch ildren w ill h ave a physiologically developed adu lt spin e, an d th u s, th e sp in e inju ries are sim ilar to th ose seen in adu lt s. Th ere is a m yriad of congen it al cer vical an om alies th at m ay cause or place a ch ild at risk for spin al cord inju r y.
470
A det ailed review of th ese en t it ies is beyon d th e scope of th is ch apter. • Upper cer vica l spin e in ju r ies ◦ Atlan to-occipit al dislocat ion (AOD) ◦ Atlan toaxial dislocat ion (AAD) ◦ Atlan toaxial rot ator y su blu xat ion (AARS) ◦ Tran slat ion al atlan toaxial su blu xat ion (TAAS) ◦ Od on toid fract u res, in clu ding syn ch on drosis fract u res ◦ Trau m at ic spon dylolisth esis of th e axis (i.e., h angm an’s fract u re) ◦ Pu re ligam en tous/soft t issue injur y (previously kn ow n as SCIWORA) ◦ Com bin at ion of th e above path ologies • Low er cer vica l spin e in ju r ies ◦ Pu re ligam en tous/soft t issue injur y (previously kn ow n as SCIWORA) ◦ Osseous anterior and/or posterior colum n injuries (e.g., com pression and burst fractures, lam inar/pedicle/facet fractures) ◦ Sp in al cord disru pt ion Biom ech an ical in stabilit y resu lt ing from any of th e above inju ries m ay p rovide an in dicat ion for op erat ive in ter ven t ion . The appropriate surgical approach is dictated by th e speci c injur y: • Occipit ocer vica l a r t h r odesis ◦ Atlan to-occipit al dislocat ion s, atlas fract u res, congen ital occipitocer vical an om alies • At la n t oa xia l a r t h r odesis ◦ Atlas fract ures, odon toid fract ures, t raum at ic C1–C2 ligam en tou s disrupt ion s, an d congen ital atlan toaxial in stabilit y • Su ba xia l cer vica l post er ior a r t h r odesis ◦ Posterior ligam en tous disrupt ion , un ilateral an d bilateral facet dislocat ion s, bu rst fract u res, an d sp on dylolisth esis • An t er ior cer vica l a ppr oa ch ◦ An an terior approach is rarely in dicated (except possibly for decom p ression of a bu rst fract u re) before th e age of 12. Th ereafter, children assum e a m ore “adult” spin e and becom e m ore suscept ible to adult-t ype inju ries.
Preoperative Considerations Field and Emergency Room Management Field m an agem en t follow s th e basic prin ciples of th e Advan ced Trau m a Life Suppor t (ATLS). Air w ay, breath ing, an d circu lat ion (ABCs) m ust be addressed. Because of a relat ively larger
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Special Considerations in Pediatric Cervical Spine Injury
Fig. 29.1a, b Pediatric backboard. Given a relatively larger head size, (a) use of a recessed head backboard or (b) elevation of the trunk by approxim ately 25 mm should be considered to maintain neutral alignment.
h ead size, th e cer vical sp in e w ill be exed w h en th e ch ild is p laced sup in e on a st an dard h orizon t al backboard.6 A recessed h ead backboard, or elevat ion of th e t ru n k by ap proxim ately 25 m m , m ust be con sidered prim arily in ch ildren aged less th an 8 years of age w ith suspected n eck injur y (Fig. 29.1a, b).6,7 On ce th e ch ild arrives in th e em ergen cy room , th e ABCs m u st be repeated, and disabilit y an d exposure sh ou ld be added. In p at ien ts presen t ing w ith hypoten sion in th e presen ce of bradycardia, n eu rogen ic sh ock m u st be di eren t iated from hypovolem ic sh ock. If a sp in al cord inju r y is p resen t , m an agem en t sh ou ld p roceed w ith vasop ressors an d m od est u id resu scitat ion . Neurologic im pairm en t sh ould focus th e em ergen cy team on a possible h ead or spin e injur y or both .
Radiographic Imaging After a careful n eurologic evaluat ion , cer vical spin al im aging sh ou ld be obt ain ed . Plain radiograph s, com p u ted tom ograp hy (CT), an d m agn et ic reson an ce im aging (MRI) m ay be con sidered. On ce a sp in e inju r y is detected, clearan ce an d im aging of all sp in e segm en ts sh ou ld be u n dert aken , con sidering a sign i can t prevalen ce of n on con t igu ous fract u res.4,8 Som e varian t s of th e n orm al an atom y or congen ital an om alies m ay be m isin terp reted as t rau m at ic inju r y.9,10 An an terolisth esis of C2–C3 is a ver y com m on n ding an d cou ld be m isdiagn osed as a ligam en tou s inju r y w h en , m ost of th e t im e, it is a p hysiologic pseu dosublu xat ion cau sed by th e hyper exibilit y of th e im m at ure cer vical spin e. A syn ch on drosis bet w een th e odon toid an d th e body of C2—w h ich m ay persist un t il a ch ild is 12 years of age—m ay be m isin terpreted as an odon toid
fract u re. Fu rth erm ore, a persisten t n eu rocen t ral syn ch on drosis of C2 can be m isdiagn osed as a h angm an’s fract ure. Th e atlan toden tal in ter val (ADI) in th e ch ild spin e is greater th an in th e adu lt , bu t sh ou ld n ot exceed 5 m m ; th is lim it is becau se of th e th icker ch ild cart ilage th at does n ot appear in radiograph s. Any p ersist ing doubt w ith st an dard radiograph s sh ould be furth er evalu ated w ith CT an d MR. • Preoperat ive im aging (Fig. 29.2a– c).
Medication Steroid adm inistration in the set ting of a spinal cord injury is still controversial and should be based on the institutional protocol. A recent system atic review of the literature found no evidence supporting the use of neuroprotective interventions for the treatm ent of spinal cord injury in children, including hypotherm ia and steroids.7 Furtherm ore, all studies that have evaluated steroids in spinal cord injury have speci cally targeted the adult population.
Surgical Timing Th e opt im al t im ing for surgical decom pression an d xat ion is also con t roversial. A recen t system at ic review st ates th at early su rgical d ecom p ression (i.e., in less th an 72 h ou rs) m ay im p rove n eu rologic ou tcom es—especially in th e set t ing of in com plete SCI an d w h en p erform ed in less th an 24 h ou rs.11 W h ile th is review suggest s early decom pression m ay ben e t th e gen eral SCI p opu lat ion , n eu rologic recover y seem s to be bet ter in th e pediat ric popu lat ion th an in adults.
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VI Special Considerations in Pediatric Em ergency Neurosurgery
a
b
c
Fig. 29.2a–c (a) Lateral radiograph and (b) sagit tal and (c) coronal CT reconstructions demonstrating an atlanto-occipital dislocation. Note the widened intervals bet ween C0–C1 and C1–C2.
Operative Management Su ccessfu l in t raop erat ive m an agem en t of th e ch ild w ith a cervical spin e inju r y dep en d s on a team ap p roach w ith th e sp in al su rgeon , pediat ric t rau m a su rgeon , an esth esiologist , an d su rgical an d radiology tech n ician s.
Anesthesia In cervical spin e injuries w ith gross in stabilit y, the neck m ust be m ain tained in a n eutral position throughout the procedure; in tubation m ay be challenging. In-line beroptic intubation should be considered, followed by induction of general anesthesia. Care to prevent both sublu xation an d distraction is im perative w h en intubating, turning, or transferring. Preoperatively, antibiotics are adm in istered at least 30 m inutes before the procedure; the authors prefer van com ycin an d cefazolin. If neurom onitoring (e.g., m otor-evoked potentials [MEPs] and som atosensory-evoked potentials [SSEPs]) is used, the anesthesia team should be alert
472
that alterations in anesthetic depth can a ect the abilit y to ob tain useful signals; the use of bispectral index (BIS) m onitoring can m inim ize this e ect. It is im perative that the anesthesiologist avoid hypotension and hypovolem ia during surgery.
Positioning Anterior Cervical Approach • • • • • •
Su pin e p osit ion Pad or tow el roll bet w een scap u las for sligh t n eck exten sion St abilize h ead w ith a ch in or foreh ead st rap Neck in n eu t ral p osit ion or rot ated to con t ralateral su rgical ap p roach site Pull both arm s togeth er caudally an d t ape th em on th e sh oulders for bet ter uoroscopic view of th e cer vical spin e Use in t raoperat ive u oroscopy to m ark th e correct level on th e skin ◦ Som e su rgeon s advocate a left-sided ap proach becau se of th e low er rates of recurren t lar yngeal n er ve inju ries 12
29 ◦ Longit u din al in cision p rovides a greater exp osu re (u su ally •
w h en th ree or m ore levels are exposed) w h ereas a t ran sverse in cision h eals w ith bet ter cosm esis Care m ust be taken not to dist ract the injured spine w ith either m anipulat ion or inadvertent elevat ion of the head of bed w hen the pat ient is in Mayf eld f xat ion.
Posterior Cervical Approach • Pron e posit ion • Use chest rolls (or a spine table for older children) and a three• • • •
pinion skull clam p or Gardner-Wells tongs in neutral position St rap arm s dow n at th e p at ien t’s side Sligh t reverse Tren delen bu rg p osit ion ing allow s for bet ter exp osu re, if th e pat ien t does not d ist ract Pad all bony prom inences and apply tight straps over the patient Th e crit ical period during w h ich th e spin e is at greatest risk is th e t ran sfer to pron e posit ion ; a t igh tly applied rigid collar or h alo m ay be u sed to redu ce th is risk.
Special Considerations in Pediatric Cervical Spine Injury
Occipitocervical Arthrodesis Indications Atlan to-occipit al dislocat ion s, atlas fract u res, congen it al occip itocer vical an om alies.
Atlantoaxial Arthrodesis Indications Atlas fract u res, odon toid fract u re, t rau m at ic C1- C2 ligam en tou s disru pt ion s, an d congen it al atlan toaxial in st abilit y.
Subaxial Cervical Posterior Arthrodesis Indications Posterior ligam en tous disrupt ion , un ilateral an d bilateral facet dislocat ion s, burst fract ures, an d spon dylolisth esis.
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VI Special Considerations in Pediatric Em ergency Neurosurgery
Operative Procedure Occipitocervical Arthrodesis w ith Contoured Rod and Segmental Wire Positioning and Preparation (Fig. 29.3)
Figure
Procedural Steps
Pearls
Fig. 29.3
Position the patient prone on a spine table, w ith the head xed to the table in a neutral position using either three -pinion head holder xation or Gardner-Wells tongs. Alternately, a standard operating table—w ith chest rolls oriented transversely across the chest and hips—may be used.
• Do not use traction in AOD cases, especially when ipping
•
•
474
the patient and in this nal position. When in slight reverse Trendelenburg, use a bolster at the feet to prevent the body from sliding down. As the head is elevated, use uoroscopy to check alignm ent. Con rm proper neutral positioning of the occiput over the atlas with uoroscopy. If fused in hyper exion, the child m ay have di cult y swallowing; if fused in excessive lordosis, the child m ay have di cult y am bulating because he cannot see his feet, and lower levels may have to be in continual kyphosis to compensate. Fusion in neutral or slight exion m ay o set the possibilit y of continued anterior growth causing hyperlordosis if a posterior fusion is perform ed in a young child. The surgical elds are prepared and draped to include the posterior inferior one-third of the skull and all the posterior part of the neck. Include preparation of the bone graft harvest site at the region of the posterior iliac crest.
29
Special Considerations in Pediatric Cervical Spine Injury
Skin Incision (Fig. 29.4)
Figure
Procedural Steps
Pearls
Fig. 29.4
Make a posterior midline, longitudinal skin incision from the base of the occiput to the most caudal spinous process desired for the cervical fusion.
• Use lateral uoroscopy for cervical spine level con rm ation. • For a short occipitocervical fusion (occiput–C1 or C2) stop the •
incision at C3 level. Do not expose m ore than needed because there is a high rate of fusion in the child spine just by exposing the posterior elements.
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VI Special Considerations in Pediatric Em ergency Neurosurgery
Subcutaneous Dissection (Fig. 29.5)
Figure
Procedural Steps
Pearls
Fig. 29.5
Extend the dissection deep w ithin the relatively avascular intermuscular septum (aka ligamentum nuchae). The suboccipital region—as w ell as the entire posterior arch of C1, C2, and other desired levels—is exposed subperiosteally.
• Cerebrospinal uid leak is not an unusual nding while dissecting. It is
• •
476
very di cult to repair the dural tear prim arily. Use gelatin sponge or onlay dural graft substitutes. Lam inectomy is not recomm ended for repair. While dissecting bet ween C1 and C2 laterally, there is often a robust perivertebral artery venous plexus. Bleeding from this plexus may be brisk but easily controlled with gelatin sponge. Exercise caution while exposing the C1 posterior arch: do not to expose m ore than 12 m m to 20 mm laterally, depending on age and anatomy, to reduce the risk of vertebral artery injury. (Always stay on bone!) In young children, there m ay be a brous union in the m idline of the arch, which can be easily breached with monopolar electrocautery.
29
Special Considerations in Pediatric Cervical Spine Injury
Fixation Points and Rod and Wire Preparation (Fig. 29.6a, b)
a
b
Figure
Procedural Steps
Pearls
Fig. 29.6
(a, b) A template of the intended shape and size of the rod is made w ith a Luque w ire. Tw o bur holes are made on each side of the occiput: 2 cm lateral to the midline and 2.5 cm above the foramen magnum. An additional pair of bur holes also may be placed above and lateral to the foramen magnum. Titanium cables are passed in an extradural plane from each bur hole to the adjacent bur hole or to the foramen magnum. Sublaminar cables are passed around C1 and C2. Thus, for an occiput to C2 fusion, there are a total of six cables (three on each side). The rod is contoured to match the template, creating a U-shape that w ill t the occipitocervical region.
• Som e children m ay have a low-lying tentorium, which
• • •
would put their sinovenous structures lower than norm al. The suboccipital dura is often quite thin and can be easily torn when m aking the bur holes. A m inim um of 1 cm of cortical bone should be left intact bet ween the holes for good xation. A bending instrum ent m ay be helpful in bending the rod.13 Usually a 135-degree head–neck angle and a slight cervical lordotic bend will t the rod to the surgical site.
These six cables w ill secure and tighten the rod w ith ongoing uoroscopy. A cross-link may be added at the caudal extent of the xation, below the spinous process.
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VI Special Considerations in Pediatric Em ergency Neurosurgery
Bone Graft (Fig. 29.7)
Figure
Procedural Steps
Pearls
Fig. 29.7
The w ound is irrigated w ith copious amounts of antibiotic solution.
• Dem ineralized bone matrix m ay be m ixed in with the autograft,
The spine and occiput are then decorticated and prepared for autogenous, onlay, and corticocancellous bone graft harvested from the posterior iliac crest.
478
as well as som e allograft bone chips, to m ake a slurry that is then applied to all decorticated surfaces. Bone m orphogenetic protein (BMP), if used, should be applied sparingly and only out laterally, away from the dural portion of the spinal canal. Occasionally, if anatomy perm its, decortication and fusion m ass m ay include the facet joints at C1–C2 and occipital condyle–C1.
29
Other Options for Occipitocervical Fixation Technique : Occipital Plate Th is tech n iqu e is best in skelet ally m at u re p at ien t s. After su b p eriosteal d issect ion an d exp osu re of t h e su boccip it al bon e w ith Bovie elect rocau ter y, p lace th e p late in p osit ion an d m ark m id lin e u sin g on e of t h e p late ap er t u res. Th e p late sh ou ld be p laced closer to th e in ion th an to th e foram en m agn u m so
Special Considerations in Pediatric Cervical Spine Injury t h ere can be en ough su r face area for ap p rop riate fu sion . Th e su boccip it al bon e m ay n eed con tou rin g to allow th e p late to lay u sh . Care m u st be t aken n ot to d isr u pt t h e ou ter cor tex fu lly (th ereby, d est abilizin g t h e con st r u ct ). Carefu lly, m ake t h e rst p reviou sly m arked bicor t ical h ole w it h a p ow er d rill an d t ap it . Rep lace t h e p late an d secu re it w it h an ap p rop riate screw . Place th e ot h er screw s w it h t h e p late in p lace in ord er to gu id e t h em . Con n ect th e p late w it h rod s to th e cer vical xat ion . Th e occip it al p late sh ou ld be fu lly covered by m u scle w h en closing.
Technique : C1 Lateral Mass Screw s 13 (Fig. 29.8a, b)
Figure
Procedural Steps
Fig. 29.8
After posterior approach to the arch of C1, use blunt dissection to expose the posterior arch of C1 and C2. Use the bipolar and hemostatic agents to control bleeding from the atlantoaxial perivertebral venous plexus. Using a Pen eld no. 4, retract the C2 nerve root caudally in order to expose the C1 lateral mass and the C1–C2 joint space just inferior to its arch. Find the medial and lateral borders of the C1 lateral mass by palpation. The inferior aspect of the posterior arch of C1 often needs to be drilled dow n to gain further access to this region and to allow the screw to sit ush w ith the proper angulation. (a) For the screw entry point, make a small hole w ith a drill at the center of C1 lateral mass. (b) With the aid of a uoroscopic lateral view of the high cervical spine, aim the drill tow ard the anterior tubercle of C1 and medialize the trajectory by 5 to 10 degrees, depending on the anatomy of the lateral mass of C1. Stop drilling w hen the drill tip is just short of posterior margin of the anterior tubercle or you feel that you have gone through the anterior cortical margin of the lateral mass of C1. Tap the hole and insert a partially threaded screw so that the shaft of the screw in contact w ith the C2 nerve root does not have any threads. The screw length is typically 34 to 36 mm. For particularly unstable or immature spines, bicortical screw xation is paramount and requires controlled tapping to penetrate the anterior cortical surface w ithout risking vascular injury. A probe is helpful in determining depth and length of screw.
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VI Special Considerations in Pediatric Em ergency Neurosurgery
Technique : C2 Pedicle Screw (Fig. 29.9)
Figure
Procedural Steps
Fig. 29.9
After exposure of the posterior arch of C2, palpate the medial portion of the C2 pedicle w ith a nerve hook or a small Pen eld and make reference of its trajectory. The entry point w ill be in the pars interarticularis of C2, lateral to the superior margin of the C2 lamina. (a) Medial and (b) cranial angulation of the screw trajectory is dependent on careful evaluation of the preoperative imaging—usually 15 to 20 degrees and 20 degrees, respectively. Again, the course of the vertebral artery on the preoperative CT w ill dictate w hether placement is advisable ; the risks of vascular injury are low.
Technique : C2 Pars Screw 14 Th e tech n ique for placem en t of a C2 pars screw is sim ilar to th at for a C1–C2 t ran sar t icular screw (see below ), except th e t arget an d t rajector y do n ot exten d to th e C1–C2 art icu lat ion . Th e en t r y poin t is ju st above th e in ferior art icular facet of C2 (3 m m cran ial an d 3 m m lateral to th e in ferior m edial th ird of th e in ferior art icu lar su rface of C2). Drilling an d screw t rajector y sh ou ld be parallel to th e angle of th e pars in terart icularis, w ith 45 to
480
60 degrees of cran ial an d eith er “st raigh t up” or 15 degrees of m ed ial angu lat ion . Th e opt im al d rilling t rajector y is eith er th e an terior t u bercle or a few m illim eters su perior. Preop erat ive review of th e CT is essen t ial, w ith focu s on th e sagit t al recon st ru ct ion to id en t ify th e vertebral ar ter y foram en . Th e length of th e screw m u st be determ in ed on th e preoperat ive CT scan . Th e screw m u st stop before reach ing th e t ran sverse foram en (u su ally 14–20 m m ). See also Ch apter 12, Fig. 12.15..
29
Special Considerations in Pediatric Cervical Spine Injury
Technique : C2 Translaminar Screw (Fig. 29.10)
Figure
Procedural Steps
Fig. 29.10
After subperiosteal dissection of the C2 posterior arch, the entry point w ill be identi ed at the base of the spinous process (i.e., the spinolaminar line), contralateral to the lamina intended for xation. The lamina itself w ill de ne the screw trajectory; make a slight dorsal angulation to avoid vertebral canal breach. When using this technique bilaterally, one entry point must be higher than the other so that one screw w ill not intersect w ith the other. The lamina must be thick enough to allow the placement of 3.5 mm screw s. Frequently, the anatomy requires a hybrid construct w ith di erent instrumentation on left and right. The C2 translaminar screw head location in longer constructs may require o set xation and may pose occasional rod bending challenges.
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VI Special Considerations in Pediatric Em ergency Neurosurgery
Atlantoaxial Arthrodesis Technique : Brooks and Jenkins 15 (Fig. 29.11)
482
Figure
Procedural Steps
Pearls
Fig. 29.11
Brooks and Jenkins xation. C1-C2 sublaminar w ires are secured over bilateral interposition bone grafts to provide a measure of stability. A standard midline longitudinal posterior approach is used to expose the arch of the atlas and lamina/spinous process of the axis. Tw o double 20-gauge w ires should be inserted under each side of the posterior arch of C1 and the lamina of C2. Tw o tricortical structured bone autografts are harvested from the iliac crest and shaped to the size of the posterior space betw een C1 and C2. The w ires, once positioned, are tightened over the graft.
• Postoperative rigid im mobilization is required •
with a Minerva cast or halo brace. Despite the appearance and the feeling of being very stable at placem ent, the wiring constructs lack the rigidit y and stabilit y of the Harm s or transarticular con gurations.16
29
Special Considerations in Pediatric Cervical Spine Injury
Technique : Gallie 17 (Fig. 29.12)
Figure
Procedural Steps
Pearls
Fig. 29.12
Gallie xation. A posterior w ire construct is bolstered w ith a notched interposition bone graft shaped to t above the lamina of C2 and over the C1 posterior arch.
• This technique avoids the need for sublaminar C2 •
The posterior arch of the atlas and the lamina of C2 are exposed no further than 1.5 cm lateral to the midline in order to prevent injury to the vertebral arteries. A w ire loop is passed upw ard under the arch of the atlas (1). Then, the free ends of the w ire are passed into the loop, notching the arch of C1 (2, 3). An interpositional, notched corticocancellous graft is harvested from the iliac crest and shaped to t the space above the lamina of C2 and over the arch of C1. The free ends (4) of the w ires are passed over the graft, securing it. One end w ill pass around or through the spinous process of C2 and then should be tw isted and tightened to the other end. Postoperative rigid immobilization is required w ith a Minerva cast or halo brace.
•
•
wires, which m ay be advisable in cases of congenital or acquired spinal stenosis. This technique is one of the least stable constructs, which could result in wire breakage and delayed deform it y. Also, because the wire is sublam inar at C1 and around the spinous process at C2, overtightening of the wires will cause a posterior translation of C1 on C2. Multiple other wiring techniques have been described, including Sonntag’s m odi ed Gallie technique.18
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VI Special Considerations in Pediatric Em ergency Neurosurgery
Technique : Posterior C1–C2 Transarticular Screw Fixation (Fig. 29.13a, b)
484
29
Special Considerations in Pediatric Cervical Spine Injury
Figure
Procedural Steps
Pearls
Fig. 29.13
Reduction of C1–C2 to anatomic or near anatomic alignment must be achieved preoperatively and con rmed w ith radiographs. A CT of the upper cervical spine is mandatory to rule out an aberrant position of the vertebral artery. Slight exion of the neck helps the exposure. A routine midline longitudinal posterior approach is performed to expose the posterior elements of C1 to C3. Identi cation of the C2–C3 facet joint w ill determine the entry point: 2 to 3 mm lateral and 2 to 3 mm rostral to the inferior, medial portion of the C2–C3 facet joint. (a) A small angulation of 10–15 degrees to medial is also made. (b) Lateral view uoroscopy is used to direct the trajectory tow ard the C1 posterior tubercle (approximately 60 degrees), running just below and parallel to the dorsal aspect of the pars interacrticularis. The assistant w ill use a tow el clamp on the spinous process of C2 to manually reduce the C1–C2 articulation before the drill crosses the joint.
• Frequently, a separate stab incision is
Once the screw is in place and reduction is achieved, the contralateral screw is placed, keeping the same reduction. Each screw should pass through four cortical surfaces (the entry point just above the inferior C2 face, each surface of the C1–2 joint space, and the anterior C1 lateral mass), making it a very strong construct. If a vertebral artery injury is suspected, continue placing the w orking screw and abort placement on the contralateral side.
• A unilateral transarticular screw,
If there is no concern for an arterial injury, then proceed w ith placement of the contralateral screw w ith the same technique. The arthrodesis is reinforced w ith a corticocancellous bone graft harvested from the iliac crest and xed w ith sublaminar w ires around the posterior elements of C1 and C2.
• There is no need for halo or Minerva
•
made caudal to the operative opening to allow the proper angulation of the drill bit. Tapping with an appropriately sized tap is recom m ended, especially with grossly unstable spines to prevent distraction of the C1–C2 joint space.
married with contralateral wire construct, is preferable where a suspected or known preexisting vertebral artery injury is present.
cast postoperatively. A rigid cervical collar only is used.
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VI Special Considerations in Pediatric Em ergency Neurosurgery
Technique : Harms Posterior C1-C2 Fusion w ith Polyaxial Screw and Rod Fixation 14 (Fig. 29.14a, b)
Figure
Procedural Steps
Fig. 29.14
Harms posterior C1–C2 fusion w ith polyaxial screw and rod xation. C1 lateral mass xation is coupled w ith C2 pars or pedicle screw s. The construct is held together w ith a rod, providing rigid xation bilaterally. A standard midline longitudinal posterior approach is used to expose the C1–C2 complex. First, 3.5-mm polyaxial screw s are inserted in the lateral masses of C1. Next, polyaxial screw s are placed bilaterally into the C2 pars interarticularis or pedicle (as described above). Manipulation of the implants allow s reduction of C1 onto C2 w hen necessary. A 3.2- to 3.5-mm rod is placed to connect the screw s and provide rigid xation. Bone graft is then placed over the decorticated posterior elements for de nitive fusion. Intraoperative reduction of subluxation can be achieved w ith placement of the screw s either recessed or proud in spite of their polyaxial nature. (a) Figure demonstrates the desired entry point and (b) the optimal screw trajectory.
486
29
Special Considerations in Pediatric Cervical Spine Injury
Subaxial Cervical Posterior Arthrodesis Technique : Interspinous Wiring Arthrodesis (Fig. 29.15)
Figure
Procedural Steps
Pearls
Fig. 29.15
A posterior midline longitudinal approach is performed to exposure the level of injury; subperiosteal exposure of the laminae and spinous processes is made. A through-and-through hole is made w ith a sharp tow el clip at the base of each spinous process to be fused. A w ire is passed through the hole at the base of the spinous process above. Then, the free ends of the w ire are draw n caudally and crisscrossed at the level of the interspinous space, before passing through the spinous process of the level below, to create a gure -of-eight pattern. The free ends of the w ire are cinched and secured. Decortication of the lamina and spinous processes is performed w ith a bur. Corticocancellous bone grafts are placed over the laminae. Rigid external immobilization is used.
• With the advent of titanium cable
•
system s, a simple loop xation of the spinous processes may provide an easy adjunct to the m ore complex lateral screw xation. The Rogers interspinous wiring and the spinous process loop constructs should not be used for stand-alone xation, but are ideal as a tension band to augm ent anterior constructs.
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VI Special Considerations in Pediatric Em ergency Neurosurgery
Technique : Posterior Arthrodesis w ith Lateral Mass Screw Fixation (Fig. 29.16a–c)
488
Figure
Procedural Steps
Fig. 29.16
Several techniques to achieve lateral mass xation have been described. Most di er w ith respect to the entry point and angulation of trajectory. The most popular are the Roy-Camille and the Magerl techniques. 19–21 . (a) The entry point for the Roy-Camille technique is at the intersection of tw o perpendicular lines that equally divide the lateral mass into four quadrants. The drill is directed perpendicular to the posterior w all of the vertebral body on sagittal view and 10 degrees lateral on coronal view. Magerl’s entry point is 1 mm medial and rostral to the same center point of the posterior surface of the lateral mass. (b, c) The trajectory is oriented parallel to the adjacent facet joint (about 45 to 60 degrees rostral) and 25 degrees lateral. Placing the monopolar blade into the joint space may assist the operator w ith the proper orientation in the sagittal plane. Careful use of variable drill bits allow s for the placement of bicortical screw s w hen extra xation is desired. Screw heads are then connected w ith longitudinal rods. A rigid cervical collar is used postoperatively.
29
Special Considerations in Pediatric Cervical Spine Injury
Closing • Th e m usculat ure an d fascia are reapproxim ated w ith 2-0 • •
absorbable su t u res. Su bcu t an eou s t issu e is closed w ith 3-0 absorbable su t u re in an inver ted, in terru pted fash ion . Th e skin is closed w ith a subcut icular, run n ing m on o lam en t absorbable su t u re.
• • •
Postoperative Management • All th ese in st rum en tat ion tech n iques in ch ildren require a p rotect ive extern al orth osis (collar). Th e collar is used n ot on ly to lim it m ot ion but also to lim it th e act ivit y of en erget ic ch ild ren . W h ile p at ien t s t reated w ith w iring tech n iqu es t ypically require a rigid extern al orth osis, pat ien t s w ith con st ru ct s th at u se screw s at each of th e levels m ay n ot requ ire a rigid collar. Sp eci c recom m en dat ion s are n oted in th e text accom p anying th e descript ion of each arth rodesis procedu re.
• •
•
For th e occipitocer vical ar th rodesis th at is det ailed in th is ch apter, th e use of a soft cer vical collar is recom m en ded. In th at case, th ere is no n eed for h alo orth osis un less bon e qualit y is poor or a m et abolic disorder w ith a h igh n on un ion rate develops. If th e ch ild is kept in a rigid collar, th e n eck an d jaw lin e m u st be m on itored carefully for skin breakdow n . Th e rigid collar, if em ployed, is t ypically w orn for th e rst 6–8 w eeks after surger y an d th en gradually discon t in ued or replaced w ith a soft on e. Th e surgical drain is rem oved after 48 h ours or w h en out put h as decreased to a m in im u m . Becau se du ral tears are com m on in th e occip u t–C1–C2 dislocat ion s, th e u se of a drain m ay be lim ited . Postoperat ive in t raven ous prophylact ic an t ibiot ics are term in ated after 24 h ou rs. Im aging (eith er plain X-ray or a CT) is p erform ed in th e im m ediate postop erat ive p eriod. Fu r th er im aging is don e w ith p lain lm s at in ter vals of 2 w eeks, 1 m on th , 3 m on th s, an d 6 m on th s after surger y. At th at poin t , a CT is perform ed to assess for fu sion . Postoperat ive im aging (Fig. 29.17a, b).
a
b Fig. 29.17a, b (a) AP and (b) lateral radiographs showing the nal occipitocervical construct.
489
VI Special Considerations in Pediatric Em ergency Neurosurgery
Special Considerations SCIWORA SCIWORA is a term u sed alm ost exclu sively in ch ildren . It is an outdated term th at w as u sed previou sly to describe a ch ild presen t ing w ith a clin ical sp in al cord inju r y—absen t any obviou s fract u re or su blu xat ion on p lain radiograp h s or CT im aging. In you ng ch ildren , th e su pp ort ing m u scu loligam en tou s st ru ct u res an d join ts can absorb forces by st retch ing an d m oving, resp ect ively. How ever, th is excess la xit y can place th e fragile an d in toleran t sp in al cord at risk for inju r y. High qu alit y MRI can alm ost alw ays iden t ify th e ligam en tou s an d sp in al cord inju r y in ch ildren w h o w ere previously design ated as SCIWORA.
Halo Application Th e applicat ion of h alos in th e pediat ric popu lat ion poses special ch allenges. Due to th e th in caliber of th e skull, pin s m ust be placed un der less pressure; usu ally m ore th an four pin s are required for adequate xat ion . Pin s n eed to be m on itored closely for in fect ion an d skull perforat ion (see Ch apter 11).
References 1. Leon ard M, Sp rou le J, McCorm ack D. Paed iat ric sp in al t rau m a an d associated inju ries. Inju r y 2007;38(2):188–193 2. Herm an MJ, McCar thy J, Willis RB, Pizzu t illo PD. Top 10 p ediat ric or th opaedic surgical em ergen cies: a case-based approach for the su rgeon on -call. Inst r Course Lect 2011;60:373–395 3. Klim o P Jr, Ware ML, Gupta N, Brockm eyer D. Cervical spine traum a in the pediatric patient. Neurosurg Clin N Am 2007;18(4):599–620 4. Carreon LY, Glassm an SD, Cam pbell MJ. Pediat ric sp in e fract ures: a review of 137 h ospit al adm ission s. J Spin al Disord Tech 2004;17(6):477–482 5. Paren t S, Mac-Th iong JM, Roy-Beau d r y M, Sosa JF, Labelle H. Sp inal cord inju r y in th e pediat ric populat ion : a system at ic review of th e literat ure. J Neurot raum a 2011;28(8):1515–1524
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6. Herzen berg JE, Hen singer RN, Dedrick DK, Ph illip s WA. Em ergen cy t ran spor t an d posit ion ing of young ch ildren w h o h ave an injur y of th e cer vical spin e: th e st an dard backboard m ay be h azardou s. J Bon e Join t Su rg Am 1989;71(1):15–22 7. Van derh ave KL, Ch iravu ri S, Caird MS, Et Al. Cer vical sp in e t rau m a in children an d adult s: perioperat ive con siderat ion s. J Am Acad Orth op Su rg 2011;19(6):319–327 8. Mah an ST, Moon ey DP, Karlin LI, Hresko MT. Mu lt ip le level inju ries in pediat ric spin al t raum a. J Traum a 2009;67(3):537–542 9. Lu st rin ES, Karakas SP, Or t iz AO, et al. Pediat ric cer vical spin e: n orm al an atom y, varian t s, an d t raum a. Radiograph ics 2003;23(3): |539–560 10. Kreykes NS, Let ton RW Jr. Current issues in the diagn osis of pediatric cer vical spin e injur y. Sem in Pediat r Surg 2010;19(4):257–264 11. Feh lings MG, Perrin RG. Th e t im ing of su rgical in ter ven t ion in th e t reat m en t of spin al cord injur y: a system at ic review of recen t clin ical eviden ce. Spin e (Ph ila Pa 1976) 2006;31(11 Suppl):S28–35 12. Bau er R, Kersch bau m er F, Poisel S, et al. An terior ap proach es. In : Atlas of Spin al Operat ions. New York: Th iem e Medical Publish ers; 1993: 4–12 13. Apostolid es PJ, Karah olios DG, Yap p RA, Son n t ag VK. Use of th e Ben dMeister rod ben der for occipitocer vical fusion : tech n ical n ote. Neurosurger y 1998;43(2):389–390 14. Harm s J, Melch er RP. Posterior C1- C2 fu sion w ith polyaxial screw an d rod xat ion . Sp in e (Ph ila Pa 1976) 2001;26(22):2467–2471 15. Brooks AL, Jen kin s EB. Atlan toaxial ar th rod esis by th e w edge com pression m eth od. J Bon e Join t Su rg [Am ] 1978;60:279 16. Melch er RP, Pu t tlit z CM, Klein st u eck FS, Lot z JC, Harm s J, Bradford DS. Biom ech an ical test ing of p osterior atlan toaxial xat ion tech n iques. Spin e (Ph ila Pa 1976) 2002;27(22):2435–2440 17. Gallie W E. Fract u res an d dislocat ion s of th e cer vical spin e. Am J Su rg 1939;46:495–499 18. Pap adop ou los SM, Dickm an CA, Son n t ag VKH. Atlan toaxial st abilizat ion in rh eum atoid ar th rit is. J Neu rosurg 1991;74:1–7 19. Roy- Cam ille R, Saillan t G, Mazel C. In tern al xat ion of th e u n st able cer vical sp in e by a posterior osteosyn th esis w ith plate an d screw s. In : Sh erk H, Dun n E, Eism on t F, et al, eds. Th e Cer vical Spin e. 2n d ed. Ph iladelph ia, PA: Lippin cot t; 1989:390–403 20. Roy- Cam ille R, Laville C, Ben azet JP. Treat m en t of low er cer vical spin e injuries - C3 to C7. Spin e 1992;17:S442–446 21. Levin e Am , Mazel C, Roy- Cam ille R. Man agem en t of fract u re separat ion s of th e ar t icular m ass u sing posterior cer vical plat ing. Spin e 1992;17:S447–454
Index
A abdom en , bon e ap storage in , 54, 63, 63f ap ret rieval after, 418, 418f abscess epid u ral. See epidu ral abscess in t racerebral. See in t racerebral abscess sp in al. See abscess ACA. See an terior com m u n icat ing arter y air em bolism , ven ou s sin us inju ries w ith , 153 Allen classi cat ion , 197 alloplast ic cran ioplast y bifron t al cran iectom y operat ive procedu re cran iectom y site prep arat ion , 435, 435f im plan t t ypes, 436f–438f, 439 posit ion ing, 428, 428f subcu t an eous dissect ion , 430–432, 430f, 431f–432f tem poral defect repair, 440, 440f tem poralis m u scle dissect ion , 433–434, 433f–434f tem poralis t ran sp osit ion , 441, 441f closing, 442 in d icat ion s for, 424, 424f, 425f postoperat ive m an agem en t m edicat ion , 442 m on itoring, 442 radiograph ic im aging, 442 preprocedu re con siderat ion s m edicat ion , 425 operat ive site prep arat ion , 425 radiograph ic im aging, 424–425 select ion algorith m for, 426f special con siderat ion s, 442–443, 442f u n ilateral cran iectom y op erat ive p roced ure cran iectom y site prep arat ion , 435, 435f im plan t t ypes, 436f–438f, 439 posit ion ing, 427, 427f skin in cision , 429, 429f subcu t an eous dissect ion , 430–432, 430f, 431f–432f tem poral defect repair, 440, 440f tem poralis m u scle dissect ion , 433–434, 433f–434f tem poralis t ran sp osit ion , 441, 441f Am erican Sp in al Injur y Associat ion (ASIA) classi cat ion system , 200 an esth esia, pediat ric con siderat ion s for, 459–460, 472 an eu r ysm , t raum at ic in d icat ion s for surger y, 133, 134f, 135–136, 135f m an agem en t , 137, 139f, 142 preprocedu re con siderat ion s, 137 an eu r ysm al ICH, 328 angiography t rau m at ic cerebrovascular injur y (TCVI), 137 ven ous sin us inju ries, 153 an terior com m un icat ing arter y (ACA), TCVI of, 135
an terior fron t al lobectom y, for cerebral con t u sion , 42, 42f an terior sp in al fu sion , 225f op erat ive procedu re closing, 234 diskectom y, 230, 230f graft placem en t an d fu sion , 232, 232f op en ing, 227, 227f plat ing, 233, 233f posit ion ing, 226, 226f redu ct ion , 231, 231f spin al colu m n exp osu re, 228, 228f ver tebral body an d in ter vertebral disk exposu re, 229, 229f an terior tem poral lobectom y, for cerebral con t usion , 50, 50f an t ibiot ics for in t racran ial in fect ion , 333, 347 for VS m alfu nct ion , 351 an t icoagu lat ion , for TCVI, 137–138, 151 an t ip latelet th erapy, for TCVI, 137–138, 151 an t ith rom bot ic th erapy, for TCVI, 137–138, 151 AO th oracolu m bar system (of Magerl), 266 arterial dissect ion , t rau m at ic in dicat ion s for su rger y, 133–135, 134f, 135f m an agem en t , 137, 142, 143f preprocedu re con siderat ion s, 137 arterioven ou s st u la, t rau m at ic in dicat ion s for su rger y, 134–136 m an agem en t , 142 preprocedu re con siderat ion s, 137 arterioven ous m alform ation (AVM), ICH associated w ith , 327–328 arth rodesis atlan toaxial. See atlan toaxial ar th rodesis occipitocer vical. See occip itocer vical arth rod esis su baxial cer vical posterior. See su baxial cer vical posterior arth rodesis ASIA classi cat ion system . See Am erican Spin al Inju r y Associat ion classi cat ion system aspirin , for TCVI, 137–138, 151 atlan toaxial arth rodesis, 470, 482 Brooks an d Jen kin s tech n ique, 482, 482f Gallie tech n iqu e, 483, 483f Harm s p osterior C1- C2 fu sion w ith p olyaxial screw an d rod xat ion , 486, 486f posterior C1-C2 t ran sar t icu lar screw xat ion , 484–485, 484f au tologou s cran ioplast y, 424 AVM. See arterioven ou s m alform at ion B basilar arter y, TCVI of, 135 bicoron al su rgical app roach , for cerebral con t usion s, 34 addressing of con t u sion , 41, 41f an terior fron t al lobectom y, 42, 42f bur h ole placem en t , 38, 38f
491
492
Inde x bicoron al surgical ap proach , for cerebral con t u sion s (cont inued) closing, 51 cran iotom y, 39, 39f dural open ing, 40, 40f posit ion ing, 35, 35f skin in cision , 36, 36f subcut an eous dissect ion , 37, 37f bifron t al cran iectom y for alloplast ic cran ioplast y cran iectom y site preparat ion , 435, 435f im plan t t ypes, 436f–438f, 439 posit ion ing, 428, 428f subcut an eous dissect ion , 430–432, 430f, 431f–432f tem poral defect repair, 440, 440f tem poralis m u scle dissect ion , 433–434, 433f–434f tem poralis t ran sp osit ion , 441, 441f decom pressive, 53 closing, 70 cran iotom y, 67, 67f dural open ing, 68, 68f du rap last y, 69, 69f in cision plan n ing, 65, 65f pediat ric, 462 posit ion ing, 64, 64f subcu t an eous dissect ion , 66, 66f blu n t vascular injuries h ead. See in t racran ial blu n t TCVI n eck. See ext racran ial blu n t TCVI bolt-t ype in t racran ial m on itors, placem en t of, 107, 107f bon e ap replacem en t closing abdom in al in cision , 422 cran ial in cision , 422 in d icat ion s for, 412 operat ive p rocedure com pleted con st ruct , 421, 421f ap replacem en t , 419, 419f iden t i cat ion an d separat ion of tem poralis m u scle, 416–417, 416f–417f posit ion ing an d prep arat ion , 413, 413f skin in cision , 414, 414f subcu t an eous abdom in al bon e ap ret rieval, 418, 418f subcu t an eous dissect ion , 415, 415f tem poralis t ran sp osit ion , 420, 420f postoperat ive m an agem en t m edicat ion , 422 m on itoring, 422 radiograph ic im aging, 422, 422f preprocedu re con siderat ion s m edicat ion , 412 operat ive eld preparat ion , 412 radiograph ic im aging, 412, 412f special con siderat ion s, 422 bon e ap storage, in abdom in al fat layer, 54, 63, 63f ap ret rieval after, 418, 418f bony debridem en t , for com bat inju ries, 391, 391f brain debridem en t , for com bat inju ries, 394, 394f brain decom p ression , for cerebellar in farct ion , 85, 85f brain t issue oxygen ten sion m on itoring closu re, 116 in d icat ion s for, 101, 458
op erat ive procedu re bolt-t ype m on itor variat ion , 107, 107f brain t issu e oxygen m on itor variat ion , 112 op en ing of du ra an d leptom en inges, 108, 108f posit ion ing, 104, 104f skin in cision , 105, 105f t w ist drill cran iostom y, 106, 106f pediat ric, 458, 459 postoperat ive m an agem en t furth er m an agem en t , 116 m edicat ion , 116 m on itoring, 116 radiograp h ic im aging, 116, 117f preprocedu re con siderat ion s coagulat ion p aram eters, 101 equ ip m en t availabilit y, 102 m edicat ion , 102 op erat ive eld preparat ion , 102, 102f–103f radiograp h ic im aging, 101 special con siderat ion s, 118 bur h ole drain age, for CSDH, 16 bur h ole placem en t , 20, 20f closing, 25 drain p lacem en t , 24, 24f dural op en ing, 21, 21f h em atom a evacuat ion , 22f, 23 posit ion ing, 19, 19f skin in cision , 19, 19f burst fract u res cer vical. See cer vical bu rst fract ures th oracic, 239 th oracolu m bar, 266 C C1-C2 fu sion w ith p olyaxial screw s an d rods in dicat ion s for, 179 op erat ive procedu re C1 screw t rajector y an d p lacem en t , 193, 193f C2 screw t rajector y an d p lacem en t , 194, 194f closing, 195 n al con st ru ct , 195, 195f posit ion ing an d su rgical site preparat ion , 191, 191f t issu e dissect ion an d exp osure, 192, 192f for pediat ric cer vical sp in e inju r y, 486, 486f postoperat ive m an agem en t m edicat ion , 195 m on itoring, 195 preprocedu re con siderat ion s m edicat ion , 179 radiograp h ic im aging, 179, 180f special con siderat ion s, 195–196 C1-C2 t ran sart icular screw in dicat ion s for, 179 op erat ive procedu re closing, 190 n al con st ru ct , 190, 190f posit ion ing, 186, 186f screw t rajector y an d p lacem en t , 189, 189f su rgical site preparat ion , 187, 187f t issu e dissect ion an d exp osure, 188, 188f for pediat ric cer vical sp in e inju r y, 484–485, 484f
Inde x postop erat ive m an agem en t m edicat ion , 190 m on itoring, 190 preprocedure con siderat ion s m edicat ion , 179 radiograph ic im aging, 179, 180f special con siderat ion s, 195–196 C1 lateral m ass screw s, for p ediat ric cer vical spin e inju r y, 479, 479f C2 pars screw, for pediat ric cer vical spin e inju r y, 480 C2 pedicle screw, for pediat ric cer vical spin e injur y, 480, 480f C2 translam inar screw, for pediatric cervical spine injury, 481, 481f calvarial recon st ruct ion , after depressed sku ll fract u re elevat ion , 98, 98f carot id arter y, TCVI of en dovascu lar m an agem en t , 138, 141f in dicat ion s for su rger y, 133–134, 134f proxim al an d dist al con t rol, 149, 149f repair of ar terial inju r y, 150, 150f su rgical dissect ion , 148, 148f carot id-cavern ou s st u la (CCF), t raum at ic, 135–136 cau da equin a syn drom e closu re, 309 in dicat ion s for su rger y, 302 operat ive proced ure lum bar diskectom y, 308, 308f lum bar lam in ectom y, 307, 307f posit ion ing, 304, 304f skin in cision , 305, 305f su bperiosteal dissect ion , 306, 306f postoperat ive m an agem en t , 309 preprocedu re con siderat ion s Foley cath eter placem en t , 303 m edicat ion , 302 operat ive eld p reparat ion , 303 radiograph ic im aging, 302, 303f special con siderat ion s, t im ing of su rger y, 309 cavern ous sin us syn drom e, t rau m at ic st u la cau sing, 135–136 CCF. See carot id-cavern ou s st ula cerebellar st roke or h em orrh age closing, 88 in dicat ion s for su rger y, 73 in t racerebral, 312–328 operat ive proced ure bony exposu re, 79, 79f bur h ole placem en t , 80, 80f cran iectom y, 81, 81f decom pression of in farcted brain , 85, 85f du ral closure, 87, 87f du ral opening, 83, 83f epidural h em atom a evacu at ion , 82, 82f h em ost asis, 86, 86f in t racerebellar h em atom a evacuat ion , 84, 84f posit ion ing, 76, 76f skin in cision , 77, 77f su bcu tan eou s dissect ion , 78, 78f postoperat ive m an agem en t m edicat ion , 89 m on itoring, 89 radiograph ic im aging, 88f, 89 ven t ricu lostom y, 88
p reprocedu re con siderat ions m edicat ion , 74 op erat ive eld p reparat ion , 74 p osit ion ing, 74 radiograp h ic im aging, 73–74, 75f ven t ricu lostom y, 74, 77, 77f cerebral blood ow m on itoring closu re, 116 in dicat ion s for, 101, 458 op erat ive procedu re bolt-t yp e m on itor variat ion , 107, 107f cerebral blood ow m on itor variat ion , 112 op en ing of dura an d leptom en inges, 108, 108f p osit ion ing, 104, 104f skin in cision , 105, 105f t w ist d rill cran iostom y, 106, 106f p ediat ric, 458, 459 p ostop erat ive m an agem en t fu rth er m an agem en t , 117 m edicat ion , 116 m on itoring, 116 radiograp h ic im aging, 116, 117f p reprocedu re con siderat ions coagu lat ion param eters, 101 equ ip m en t availabilit y, 102 m edicat ion , 102 op erat ive eld p reparat ion , 102, 102f–103f radiograp h ic im aging, 101 sp ecial con siderat ion s, 118 cerebral con t u sion s bicoron al ap p roach op erat ive p rocedu re add ressing of con t u sion , 41, 41f an terior fron t al lobectom y, 42, 42f bu r h ole p lacem en t , 38, 38f closing, 51 cran iotom y, 39, 39f d u ral op en ing, 40, 40f p osit ion ing, 35, 35f skin in cision , 36, 36f su bcu t an eou s dissect ion , 37, 37f in dicat ion s for su rger y, 33 m od i ed pterion al ap p roach operat ive p rocedu re add ressing of con t u sion , 49, 49f an terior tem poral lobectom y, 50, 50f bu r h ole p lacem en t , 46, 46f closing, 51 cran iotom y, 47, 47f d u ral op en ing, 48, 48f p osit ion ing, 43, 43f skin in cision , 44, 44f su bcu t an eou s dissect ion , 45, 45f p ostop erat ive m an agem ent m edicat ion , 51 m on itoring, 51 radiograp h ic im aging, 51, 51f p reprocedu re con siderat ions ch oice of su rgical app roach , 34 m edicat ion , 34 op erat ive eld p reparat ion , 34 radiograp h ic im aging, 33, 33f
493
494
Inde x cerebral edem a, during decom pressive cran iectom y, 71 cerebrospin al uid (CSF) com bat-associated leak of, 398, 400f pen et rat ing h ead inju ries w ith leak of, 119–120, 132 t rau m at ic rhin orrh ea of. See t rau m at ic CSF rh in orrh ea rep air cerebrovascular injur y, t rau m at ic. See t raum at ic cerebrovascular inju r y cer vical bu rst fract ures closing, 212 in d icat ion s for su rger y, 197, 197t, 198f–199f, 200 in it ial evaluat ion of, 200 m ech an ism s of inju r y, 197, 198f–199f m edical m an agem en t of, 200 operat ive p rocedure, 197t, 200–201 allograft placem en t , 210, 210f an terior locking p late placem en t , 211, 211f corp ectom y, 209, 209f deep cer vical invest ing fascia iden t i cat ion , 205, 205f diskectom y, 208, 208f incision an d subp lat ysm al dissect ion , 204, 204f om ohyoid iden t i cat ion , 204, 204f posit ion ing, 203, 203f prevertebral fascia iden t i cat ion , 206, 206f self-ret ain ing ret ractor p lacem en t , 207, 207f postoperat ive m an agem en t m edicat ion , 212 m on itoring, 212 radiograph ic im aging, 212, 212f prep rocedure con siderat ion s op erat ive eld preparat ion , 201 radiograph ic im aging, 201, 202f special con siderat ion s, 212 cer vical collar, for pediat ric cer vical sp in e injur y, 490 cer vical epidu ral spin al cord com p ression , su rgical app roach es to, 291 cer vical facet d islocat ion an terior approach op erat ive p rocedure, 225f closing, 234 diskectom y, 230, 230f graft placem en t an d fu sion , 232, 232f op en ing, 227, 227f plat ing, 233, 233f posit ion ing, 226, 226f redu ct ion , 231, 231f spin al colum n exposure, 228, 228f ve r t eb ra l b od y an d in t e r ve r t eb ra l d isk exp osu re, 2 2 9 , 229f closed reduct ion , 215 exam in at ion , 214 indicat ion s for su rger y, 214 op erat ive m anagem en t approach , 215 tech n iqu es, 215 posterior approach operat ive p rocedu re, 216f closing, 225 decom pression an d redu ct ion , 220, 220f fusion preparat ion , 221, 221f posit ion ing, 217, 217f posterolateral fusion , 224, 224f rod placem en t , 223, 223f screw placem en t , 222, 222f subcut an eous dissect ion , 218–219, 218f, 219f
postoperat ive m an agem en t m edicat ion , 234 m on itoring, 234 radiograp h ic im aging, 234, 235f preprocedu re con siderat ion s m edicat ion , 215 op erat ive eld preparat ion , 215 radiograp h ic im aging, 215 special con siderat ion s, 234 cervical sp in e inju r y, pediat ric. See p ediat ric cer vical spin e injur y cervical t ract ion . See closed spin al t ract ion Chan ce fract u re. See exion -dist ract ion fract u res ch ron ic su bd ural h em atom a (CSDH) bur h ole drain age operat ive procedu re bur h ole placem en t , 20, 20f closing, 25 drain p lacem en t , 24, 24f dural op en ing, 21, 21f h em atom a evacuat ion , 22f, 23 posit ion ing, 19, 19f skin in cision , 19, 19f ch aracterist ics of, 17, 17f in dicat ion s for su rger y all procedu res, 16 m in im ally invasive procedu res, 16 postoperat ive m an agem en t m edicat ion , 30 m on itoring, 29 radiograp h ic im aging, 30, 30f, 31f t w ist drill cran iostom y care, 29, 30f preprocedu re con siderat ion s m edicat ion , 17–18 op erat ive eld preparat ion , 18 radiograp h ic im aging, 16–17, 17f, 18f, 18t sm all cran iotom y op erat ive p rocedu re bur h ole placem en t , 20, 20f closing, 25 drain p lacem en t , 24, 24f dural op en ing, 21, 21f h em atom a evacuat ion , 22f, 23 posit ion ing, 19, 19f skin in cision , 19, 19f special con siderat ion s, 31 t w ist drill cran iostom y operat ive procedu re cath eter p lacem en t , 28, 28f closing, 29, 29f drilling, 27, 27f posit ion ing, 26, 26f skin in cision , 26, 26f closed cran ial fract ures, 90, 99 closed sp inal t ract ion in dicat ion s for, 170 op erat ive procedu re pin p lacem en t , 174, 174f pin site select ion , 173, 173f posit ion ing, 172, 172f vest p lacem en t , 176f w eigh t placem en t an d cou n ter t ract ion , 175, 175f pediat ric, 490 postoperat ive m an agem en t m edicat ion , 177 m on itoring, 177
Inde x pin site m an agem en t , 177 radiograph ic im aging, 176f, 177 preprocedu re con siderat ion s m edicat ion , 170 operat ive eld p reparat ion , 170 radiograph ic im aging, 170, 171f special con siderat ion s, 177 com bat-associated pen et rat ing sp in e inju r y (PSI) closu re, 410 in dicat ion s for su rger y, 398, 399f, 400f, 401f operat ive tech n iqu e decom pression , 408, 408f dissect ion , 406, 406f du ral explorat ion /repair, 409, 409f in st ru m en t at ion /fu sion, 410 lam in ectom y, 407, 407f posit ion ing, 404–405, 404f–405f postoperat ive m an agem en t , 410 preprocedu re con siderat ion s an esth esia issu es, 403 associated inju ries, 402 equ ipm en t/set-u p, 402–403 in it ial evaluat ion , 402 in it ial m edical m an agem en t , 402 n eurom on itoring, 403 prepping/in cision , 403 radiograph ic im aging, 402 t act ical scen ario, 402 com bat cran ial operat ion s closing, 396 in dicat ion s for, 386 operat ive proced ure bony debridem en t , 391, 391f brain debridem en t , 394, 394f h em icran iectom y, 393, 393f pericran ial graft , 395, 395f posit ion ing an d p reparat ion , 388, 388f scalp in cision , 392, 392f skull base recon st ru ct ion , 395, 395f soft t issue debridem en t , 390, 390f urgen t h em ost asis, 389, 389f postoperat ive m an agem en t m edicat ion , 396 m on itoring, 396 radiograph ic im aging, 396, 396f preprocedu re con siderat ion s con su ltat ion /team w ork, 386 m edicat ion s, 387 operat ive eld p reparat ion , 387 radiograph ic im aging, 386, 387f special con siderat ion s, 397 com pression fract u res th oracic, 239 th oracolum bar, 266 com puted tom ograp hy (CT) bon e ap replacem en t , 412, 412f, 422, 422f cerebellar st roke or h em orrh age, 73–74, 75f, 88f, 89 cerebral con t u sion s, 33, 33f, 51, 51f cer vical bu rst fract ures, 201 cer vical facet dislocat ion , 215, 234 closed sp in al t ract ion , 170, 171f com bat-associated pen et rat ing sp in e inju r y, 402
com bat cran ial op erat ion s, 386, 387f, 396, 396f CSDH, 16–17, 17f, 18f, 18t, 30, 30f, 31f d ecom pressive cran iectom y, 53–54, 54f, 70, 71f d epressed sku ll fract u re elevat ion , 90, 91f, 99, 99f epidu ral h em atom a, 2, 3f, 14, 15f fron t al sin u s inju ries, 444, 445f, 456 ICH, 312, 312f, 320, 320f, 327, 327f, 328f in t racran ial in fect ion , 331, 332f, 347, 347f invasive n eu rom on itoring, 116, 117f odon toid fract u res, 179, 180f p ediat ric cer vical sp in e inju r y, 471, 472f p ediat ric TBI, 459, 459f p it u it ar y ap oplexy, 370, 371f sp in al epid u ral com pression , 288, 290f su bd u ral h em atom a, 2, 3f, 14, 15f su boccipit al t raum a, 73–74, 75f, 88f, 89 su rgical debridem en t of p en et rat ing h ead inju ries, 120, 121f, 131, 131f th oracic fract u res, 239 th oracolu m bar fract ures, 267, 267f t rau m at ic CSF rh in orrh ea repair, 444, 445f, 456 ven ou s sin us injuries, 153, 154f, 168, 168f ven t ricu lar sh u n t m alfu n ct ion , 350, 350f, 368, 368f com p u ted tom ograp hy angiogram (CTA) com bat-associated p en et rat ing sp in e inju r y, 402 ICH, 312, 313f, 320, 320f TCVI, 136–137, 136f, 151 com p u ted tom ograp hy ven ography (CTV), ven ou s sin u s injuries, 153, 154f, 168, 168f corpectom y for cer vical burst fract u res, 209, 209f for th oracic fract u res, 251f corpectom y an d diskectom y, 254, 254f d rilling, 253, 253f p edicle screw s, 256, 256f rem oval of facet com plex, 252, 252f rib h ead t rap door osteotom y, 255, 255f cor t icosteroids. See steroids costot ran sversectom y, for th oracic fract ures, 264 cran ial bon e ap rep lacem en t . See bon e ap replacem en t cran ial fract u re, d epressed. See depressed sku ll fract ure elevat ion cran iectom y for allop last ic cran ioplast y. See bifron t al cran iectom y; u n ilateral cran iectom y for cerebellar stroke or hem orrhage or suboccipital traum a, 81, 81f d ecom pressive. See decom pressive cran iectom y for dep ressed sku ll fract u re elevat ion , 95, 95f for ICH. See m idlin e su boccipit al cran iectom y p ediat ric, 458, 460–461 for p en et rat ing h ead injuries, 119–120 cran iop last y alloplast ic. See allop last ic cran iop last y au tologou s, 424 p ediat ric, 458 cran iostom y. See t w ist drill cran iostom y cran iotom y for cerebral con t usion bicoron al ap p roach , 39, 39f m od i ed pterion al ap p roach , 47, 47f for CSDH, 16 bu r h ole p lacem en t , 20, 20f closing, 25
495
496
Inde x cran iotom y (cont inued) drain p lacem en t , 24, 24f du ral op en ing, 21, 21f h em atom a evacu at ion , 22f, 23 posit ion ing, 19, 19f skin incision , 19, 19f for decom pressive h em icran iectom y bifron t al, 67, 67f fron totem poropariet al, 59, 59f for ep idu ral or su bdu ral h em atom a, 7, 7f for ICH. See fron t al cran iotom y for in t racerebral abscess, 343, 343f pediat ric, 458, 460, 465, 465f for p en et rat ing h ead inju ries, 119–120, 126, 126f for ven ou s sin u s inju ries an terior on e-th ird superior sagit t al sin u s, 157, 157f posterior t w o-th irds su perior sagit tal sin u s, torcu lar h eroph ili, an d dom in an t t ran sverse sin u s, 164, 164f CSDH. See ch ron ic su bdural h em atom a CSF. See cerebrospin al uid CT. See com pu ted tom ography CTA. See com p uted tom ography angiogram CTV. See com pu ted tom ography ven ograp hy D DC. See decom pressive cran iectom y d ebridem en t . See surgical debridem en t of pen et rat ing h ead inju ries d ecom pressive cran iectom y (DC) bifron t al operat ive procedure closing, 70 cran iotom y, 67, 67f du ral open ing, 68, 68f du raplast y, 69, 69f in cision plann ing, 65, 65f posit ion ing, 64, 64f subcu t an eous dissect ion , 66, 66f fron t ot e m p orop ar iet al h e m icran ie ctom y op e rat ive p roced u re bon e ap elevat ion , 59, 59f bon e ap storage, 63, 63f bur h ole placem en t , 58, 58f closing, 70 du ral open ing, 61, 61f du raplast y, 62, 62f posit ion ing, 55, 55f skin in cision , 56, 56f subcu t an eous dissect ion , 57, 57f tem poral cran iectom y re n em en t , 60, 60f in d icat ion s for, 53, 458 pediat ric, 458, 460–461 postoperat ive m an agem en t m edicat ion , 70 m onitoring, 70 radiograph ic im aging, 70, 71f preprocedu re con siderat ion s m edicat ion , 54 operat ive eld preparat ion , 54 radiograph ic im aging, 53–54, 54f special con siderat ion s, 71 Den is classi cat ion , 266
den s fract u res. See odon toid fract ures dep ressed sku ll fract ure elevat ion closing, 99 in dicat ion s for, 90, 458 op erat ive procedu re calvarial recon st ru ct ion , 98, 98f cran iectom y, 95, 95f dural tear exp lorat ion , 96, 96f fract u re elevat ion , 96, 96f posit ion ing, 92, 92f skin in cision , 93, 93f su bcut an eous dissect ion , 94, 94f ven ou s sin u s rep air, 97, 97f pediat ric, 458, 460 postoperat ive m an agem en t m edicat ion , 99 radiograp h ic im aging, 99, 99f preprocedu re con siderat ion s m edicat ion , 90 op erat ive eld preparat ion , 90 radiograp h ic im aging, 90, 91f special con siderat ion s, 99 diskectom y for cau da equ in a syn drom e, 308, 308f for cer vical bu rst fract u res, 208, 208f for cer vical facet dislocat ion s, 230, 230f for th oracic fract ures, 254, 254f dom in an t t ran sverse sin u s inju ries closing, 165 in dicat ion s for su rger y, 153 op erat ive procedu re cran iotom y, 164, 164f direct repair, 165, 165f gen eral con siderat ion s, 154 posit ion ing, 162, 162f sin u s in terposit ion graft , 167 sin u s patch , 166, 166f skin in cision , 163, 163f tam pon ade, 165 postoperat ive m an agem en t m edicat ion , 168 m on itoring, 168 radiograp h ic im aging, 168, 168f preprocedu re con siderat ion s m edicat ion , 153 op erat ive eld preparat ion , 153–154 radiograp h ic im aging, 153, 154f special con siderat ion s, 168 drain p lacem en t for CSDH, 24, 24f, 29, 30f for epidu ral or su bdu ral h em atom a, 13, 13f EVD. See extern al ven t ricu lar drain dura closu re of after cerebellar st roke or h em orrh age or su boccipit al t raum a su rger y, 87, 87f after grow ing sku ll fract ure rep air, 467, 467f after h em atom a evacuat ion , 11, 11f after in t racran ial in fect ion , 344, 344f explorat ion of, for com bat-associated pen et rat ing spin e inju r y, 409, 409f
Inde x open ing of for cerebellar st roke or h em orrh age, 83, 83f for cerebral con t u sion s, 40, 40f, 48, 48f for CSDH, 21, 21f for decom pressive h em icran iectom y, 61, 61f, 68, 68f for epidu ral or su bdu ral h em atom a, 9, 9f for ICH, 317, 317f, 325, 325f for in t racran ial in fect ion , 341, 341f for in t racran ial m on itoring, 108, 108f for suboccip ital t rau m a, 83, 83f for surgical debridem en t of pen et rat ing h ead inju ries, 127, 127f tearing of, depressed skull fract ures w ith , 96, 96f du ral venous sin u s inju r y. See ven ou s sin u s inju ries duraplast y for decom pressive h em icran iectom y bifron t al, 69, 69f fron totem poropariet al, 62, 62f for surgical debridem en t of pen et rat ing h ead inju ries, 130, 130f E EDH. See epidural h em atom a en dovascu lar m an agem en t of ext racran ial blu n t TCVI, 137–138, 139f of ext racran ial pen et rat ing TCVI, 138, 141f epidural abscess, 330 closu re, 347 in dicat ion s for su rger y, 331 operat ive proced ure abscess rem oval, 340, 340f bon e ap elevat ion , 339, 339f in cision , 336, 336f pericran ial ap h ar vest , 337, 337f posit ion ing, 334–335, 334f–335f t e m p or alis d ivision a n d b u r h ole p lace m e n t , 3 3 8 , 338f postop erat ive m an agem en t fu r th er m an agem en t , 348 m edicat ion , 347 m on itoring, 347 radiograph ic im aging, 347, 347f preprocedure con siderat ion s m edicat ion , 333 operat ive eld p rep arat ion , 333 radiograph ic im aging, 331, 332f special con siderat ion s, 348 sp in al. See sp in al epid u ral abscess epidural h em atom a (EDH) cerebellar st roke or h em orrh age w ith , 73, 73f, 82, 82f in dicat ion s for su rger y, 2, 458 operat ive proced ure bon e ap replacem en t , 12, 12f closing, 14 cran iotom y, 7, 7f drain placem en t , 13, 13f h em atom a evacu at ion , 8, 8f posit ion ing, 4, 4f skin in cision , 5, 5f su bcu tan eous dissect ion , 6, 6f pediat ric, 458, 460
p ostop erat ive m an agem en t m edicat ion , 14 m on itoring, 14 radiograp h ic im aging, 14, 15f p reprocedu re con siderat ions m edicat ion , 2 op erat ive eld p reparat ion , 2 radiograp h ic im aging, 2, 3f sp ecial con siderat ion s, 15 sp in al. See sp in al ep idu ral h em atom a su boccipit al t raum a w ith , 73, 73f, 82, 82f extern al ven t ricu lar drain (EVD) closu re, 116 d u ring decom pressive cran iectom y, 54 for ICH, 328–329 in dicat ion s for, 101, 458 p ediat ric, 458, 459–460 p lacem en t op erat ive p rocedu re an atom ic lan dm arks for, 102, 102f–103f bolt-t yp e m on itor variat ion , 107, 107f cath eter t u n n elling an d secu ring, 110, 110f d rain variat ion , 109, 109f op en ing of dura an d leptom en inges, 108, 108f p osit ion ing, 104, 104f skin in cision , 105, 105f t w ist d rill cran iostom y, 106, 106f p ostop erat ive m an agem en t fu rth er m an agem en t , 116 m edicat ion , 116 m on itoring, 116 radiograp h ic im aging, 116, 117f p reprocedu re con siderat ions coagu lat ion param eters, 101 equ ip m en t availabilit y, 102 m edicat ion , 102 op erat ive eld p reparat ion , 102, 102f–103f radiograp h ic im aging, 101 sp ecial con siderat ion s, 118 ext racran ial blu n t TCVI in dicat ion s for su rger y, 133–134, 133t, 134f, 135f m an agem en t algorith m for, 138f en d ovascular, 137–138, 139f m edical, 137 p ostop erat ive m an agem en t m edicat ion , 151 m on itoring, 151 radiograp h ic im aging, 151 p reprocedu re con siderat ions, 136–137, 136f sp ecial con siderat ion s, 151 ext racran ial pen et rat ing TCVI in dicat ion s for su rger y, 134 m an agem en t algorith m for, 140f closu re, 138 en d ovascular, 138, 141f op erat ive procedu re carot id arter y dissect ion , 148, 148f in it ial dissect ion , 147, 147f p osit ion ing, 145, 145f p roxim al an d dist al ar ter y con t rol, 149, 149f
497
498
Inde x ext racran ial pen et rat ing TCVI (cont inued) repair of arterial inju r y, 150, 150f skin in cision , 146, 146f postoperat ive m an agem en t m edicat ion , 151 m on itoring, 151 radiograph ic im aging, 151 prep rocedure con siderat ion s, 137 special con siderat ion s, 151 F facetectom y, for th oracolum bar fract u res, 272–273, 272f facet fusion , for th oracolu m bar fract u res, 281, 281f facet join t dislocat ion . See cer vical facet dislocat ion facet s, an atom y of, 237 brin sealan t applicat ion , for fron t al sin u s su rger y, 454, 454f exion -dist ract ion fract ures th oracic, 239 th oracolu m bar, 266 uoroscopy, for p it uit ar y apoplexy, 373–374, 373f, 374f foreign body rem oval, for in t racran ial p en et rat ing injur y, 144, 144f fract ure-dislocat ion inju r y th oracic spin e, 239 th oracolu m bar, 266 fract ure elevat ion . See depressed skull fract u re elevat ion fron tal cran iotom y, for su praten torial ICH cran iotom y, 316, 316f dural open ing, 317, 317f hem atom a evacuat ion , 318–319, 318f, 319f posit ion ing an d skin in cision , 314, 314f subcu t an eous dissect ion , 315, 315f fron tal lobe con t usion . See cerebral con t usion s fron tal lobectom y, for cerebral con t usion , 42, 42f fron t al sin u s cran ializat ion , after in t racran ial in fect ion , 344, 344f fron tal sin u s inju ries closing, 456 in d icat ion s for su rger y, 444 operat ive p rocedure bicoron al in cision, 446, 446f cran ial bon e ap replacem en t , 455, 455f brin sealan t ap plicat ion , 454, 454f fragm en t rem oval an d cat alogu ing, 448, 448f fron ton asal du ct packing, 452, 452f fron ton asal du ct paten cy con rm at ion , 449, 449f pericran ial ap elevat ion an d rot at ion , 453, 453f posterior t able rem oval, 450, 450f sin us m ucosa bu rn ing, 451, 451f subperiosteal dissect ion , 447, 447f postoperat ive m an agem en t , 456 prep rocedure con siderat ion s, 444, 445f special con siderat ion s, 456 fron totem poropariet al decom p ressive h em icran iectom y, 53 bon e ap elevat ion , 59, 59f bon e ap storage, 63, 63f bur h ole placem en t , 58, 58f closing, 70 du ral open ing, 61, 61f du raplast y, 62, 62f pediat ric, 462 posit ion ing, 55, 55f
skin in cision , 56, 56f su bcut an eous dissect ion , 57, 57f tem p oral cran iectom y re n em en t , 60, 60f G Gardn er-Wells tongs in dicat ion s for, 170 op erat ive procedu re pin p lacem en t , 174, 174f pin site select ion , 173, 173f posit ion ing, 172, 172f w eigh t placem en t an d cou n ter t ract ion , 175, 175f postoperat ive m an agem en t m edicat ion , 177 m on itoring, 177 pin site m an agem en t , 177 radiograp h ic im aging, 176f, 177 preprocedu re con siderat ion s m edicat ion , 170 op erat ive eld preparat ion , 170 radiograp h ic im aging, 170, 171f special con siderat ion s, 177 grow ing sku ll fract ure repair closing, 469 gen eral su rgical prin cip les, 460 in dicat ion s for, 458 op erat ive procedu re, 462 bony defect rep air, 468, 468f cran iotom y, 466, 466f dural defect closu re, 467, 467f in cision , 464, 464f posit ion ing, 463, 463f su bcut an eous dissect ion , 465, 465f postoperat ive m an agem en t m on itoring, 469 radiograp h ic im aging, 469, 469f w ou n d m an agem en t , 469 preprocedu re con siderat ion s an esth esia, 459–460 op erat ive eld preparat ion , 460 radiograp h ic im aging, 459, 459f H h alo ring t ract ion in dicat ion s for, 170 op erat ive procedu re pin p lacem en t , 174, 174f pin site select ion , 173, 173f posit ion ing, 172, 172f vest p lacem en t , 176f w eigh t placem en t an d cou n ter t ract ion , 175, 175f pediat ric, 490 postoperat ive m an agem en t m edicat ion , 177 m on itoring, 177 pin site m an agem en t , 177 radiograp h ic im aging, 176f, 177 preprocedu re con siderat ion s m edicat ion , 170 op erat ive eld preparat ion , 170 radiograp h ic im aging, 170, 171f special con siderat ion s, 177
Inde x h alo vest t ract ion , 170, 172, 176f h ead injuries pen et rat ing. See pen et rat ing h ead inju ries TBI. See t raum at ic brain injur y TCVI. See t raum at ic cerebrovascular injur y h em atom a evacu at ion CSDH, 22f, 23 epidural, 8, 8f, 82, 82f ICH in fraten torial, 326, 326f su praten torial, 318–319, 318f, 319f in t racerebellar, 84, 84f spin al epidu ral, 294, 294f su bdu ral, 10, 10f h em icran iectom y for com bat h ead inju ries, 393, 393f decom pressive. See fron totem poropariet al decom p ressive h em icran iectom y h em orrh age cerebellar. See cerebellar st roke or h em orrh age in t racerebral. See in t racerebral h em orrh age ven ou s sin u s injuries w ith , 153 h ep arin , for TCVI, 137 hyd roceph alus, after decom p ressive cran iectom y, 70 hyd roxyap at ite cem en t com pou n d , for alloplast ic cran iop last y, 438f, 439, 442 I ICA. See in tern al carot id arter y ICH. See in t racerebral h em orrh age ICP m on itoring. See in t racran ial pressu re m on itoring in fect ion epidural. See epidu ral abscess in t racran ial. See in t racran ial in fect ion pen et rat ing h ead inju ries w ith , 119–120, 132 sh un t , 351 sp in al. See sp in al ep idu ral abscess in fraten torial ICH closing, 327 in dicat ions for surger y, 320 m idlin e suboccip it al cran iectom y operat ive procedu re cran iectom y, 323–324, 323f–324f du ral open ing, 325, 325f h em atom a evacuat ion , 326, 326f posit ion ing, 321, 321f skin in cision an d su bcu t an eou s dissect ion , 322, 322f postop erat ive m an agem en t , 327, 327f, 328f preprocedu re con sid erat ion s in it ial m an agem en t , 320 m edicat ion , 320 operat ive eld preparat ion , 320 radiograph ic im aging, 320, 320f special con siderat ion s, 327–329 in tern al carot id arter y (ICA), TCVI of en dovascular m an agem en t , 138, 141f in dicat ions for surger y, 133–134 in terspin ou s w iring arth rod esis, for pediat ric cer vical sp in e injur y, 487, 487f in t racerebellar h em atom a, 73, 73f, 84, 84f in t racerebral abscess, 330 closu re, 347 in dicat ions for surger y, 331
op erat ive procedu re bon e ap elevat ion , 339, 339f d u r al clo su re a n d cr a n ia lizat io n o f fron t a l sin u s, 3 4 4 , 344f d u ral op en ing, 341, 341f in cision , 336, 336f op en cran iotom y, 343, 343f p ericran ial ap h ar vest , 337, 337f p osit ion ing, 334–335, 334f–335f stereot act ic approach , 345–346, 345f–346f tem poralis division an d bu r h ole placem en t , 338, 338f p ostop erat ive m an agem en t fu rth er m an agem en t , 348 m edicat ion , 347 m on itoring, 347 radiograp h ic im aging, 347, 347f p reprocedu re con siderat ions m edicat ion , 333 op erat ive eld p reparat ion , 333 radiograp h ic im aging, 331, 332f sp ecial con siderat ion s, 348 in t racerebral h em orrh age (ICH), 312. See cerebellar st roke or h em orrh age in fraten torial. See in fraten torial ICH su praten torial. See su p raten torial ICH in t racran ial blu n t TCVI in dicat ion s for su rger y, 134–136 m an agem en t , 142, 143f algorith m for, 142f p ostop erat ive m an agem en t m edicat ion , 151 m on itoring, 151 radiograp h ic im aging, 151 p reprocedu re con siderat ions, 137 sp ecial con siderat ion s, 151 in t racran ial hyp erten sion , decom p ressive cran iectom y for. See decom p ressive cran iectom y in t racran ial in fect ion closu re, 347 in dicat ion s for su rger y, 331 op erat ive procedu re bon e ap elevat ion , 339, 339f d u ral closu re an d cran ializat ion of fron t al sin us, 344, 344f d u ral op en ing, 341, 341f epidu ral abscess rem oval, 340, 340f in cision , 336, 336f op en cran iotom y, 343, 343f p ericran ial ap h ar vest , 337, 337f p osit ion ing, 334–335, 334f–335f stereot act ic approach to in t raparen chym al abscess, 345–346, 345f–346f su bd u ral em pyem a rem oval, 342, 342f tem poralis division an d bu r h ole placem en t , 338, 338f p ostop erat ive m an agem en t fu rth er m an agem en t , 348 m edicat ion , 347 m on itoring, 347 radiograp h ic im aging, 347, 347f p reprocedu re con siderat ions m edicat ion , 333 op erat ive eld p rep arat ion , 333 radiograp h ic im aging, 331, 332f
499
500
Inde x in t racran ial in fect ion (cont inued) special con siderat ion s, 348 t ypes of, 330 in t racranial p en et rat ing TCVI in d icat ion s for surger y, 136 m an agem en t , 142, 144, 144f algorith m for, 143f postoperat ive m an agem en t m edicat ion , 151 m on itoring, 151 radiograph ic im aging, 151 preprocedu re con siderat ion s, 137 special con siderat ion s, 151 in t racranial p ressu re (ICP) m on itoring closu re, 116 in d icat ion s for, 101, 458 m on itor p lacem en t op erat ive procedu re bolt-t ype m on itor variat ion , 107, 107f cath eter t un n elling an d secu ring, 110, 110f EVD variat ion , 109, 109f in t raparen chym al probe variat ion , 111, 111f open ing of du ra an d leptom en inges, 108, 108f posit ion ing, 104, 104f skin in cision , 105, 105f t w ist drill cran iostom y, 106, 106f pediat ric, 458, 459 postoperat ive m an agem en t fu rth er m an agem en t , 116 m edicat ion , 116 m onitoring, 116 radiograph ic im aging, 116, 117f preprocedu re con siderat ion s coagulat ion param eters, 101 equip m en t availabilit y, 102 m edicat ion , 102 operat ive eld preparat ion , 102, 102f–103f radiograph ic im aging, 101 special con siderat ion s, 118 invasive n eurom on itoring closu re, 116 in d icat ion s for, 101, 458 in t racran ial m on itor placem en t op erat ive procedu re bolt-t ype m onitor variat ion , 107, 107f brain t issue oxygen m on itor variat ion , 112 cath eter t un n elling an d secu ring, 110, 110f cerebral blood ow m on itor variat ion , 112 EVD variat ion , 109, 109f in t raparen chym al probe variat ion , 111, 111f m icrod ialysis cath eter variat ion , 112 open ing of du ra an d leptom en inges, 108, 108f posit ion ing, 104, 104f skin in cision , 105, 105f t w ist drill cran iostom y, 106, 106f pediat ric, 458, 459 postoperat ive m an agem en t fu rth er m an agem en t , 116–118 m edicat ion , 116 m onitoring, 116 radiograph ic im aging, 116, 117f preprocedu re con siderat ion s coagulat ion param eters, 101 equip m en t availabilit y, 102
m edicat ion , 102 op erat ive eld preparat ion , 102, 102f–103f radiograp h ic im aging, 101 SjVO2 m on itor p lacem en t operat ive procedu re posit ion ing, 113, 113f skin in cision an d in sert ion , 114, 114f veri cat ion of posit ion, 115, 115f special con siderat ion s, 118 J jugu lar ven ous sat urat ion (SjVO2 ) m on itoring closu re, 116 in dicat ion s for, 101 op erat ive p rocedu re posit ion ing, 113, 113f skin in cision an d in sert ion , 114, 114f veri cat ion of posit ion , 115, 115f postoperat ive m an agem en t fu rth er m an agem en t , 116–117 m edicat ion , 116 m on itoring, 116 radiograp h ic im aging, 116 prep rocedure con siderat ion s coagu lat ion p aram eters, 101 equ ip m en t availabilit y, 102 m edicat ion , 102 op erat ive eld preparat ion , 102, 102f–103f radiograp h ic im aging, 101 special con siderat ion s, 118 K Koch er’s p oin t , 102, 102f–103f L lam in ectom y for cau da equ in a syn drom e, 307, 307f for com bat-associated pen et rating spin e inju r y, 407, 407f for sp in al ep idu ral com pression , 288, 291 m etast at ic disease, 297, 297f SEA, 295–296, 295f, 296f SEH, 293–294, 293f, 294f for th oracic fract u res, 246, 246f leptom en ingeal cyst closing, 469 gen eral su rgical prin cip les, 460 in dicat ion s for surger y, 458 op erat ive p rocedu re, 462 bony defect rep air, 468, 468f cran iotom y, 466, 466f du ral defect closu re, 467, 467f in cision , 464, 464f posit ion ing, 463, 463f su bcu t an eou s dissect ion , 465, 465f postoperat ive m an agem en t m on itoring, 469 radiograp h ic im aging, 469, 469f w ou n d m an agem en t , 469 prep rocedure con siderat ion s an esth esia, 459–460 op erat ive eld preparat ion , 460 radiograp h ic im aging, 459, 459f leptom en inges open ing, for in t racran ial m on itoring, 108, 108f
Inde x lobectom y, for cerebral con t u sion an terior fron t al, 42, 42f an terior tem poral, 50, 50f lum bar epidural spinal cord compression, surgical approaches to, 291 M Magerl tech n ique. See C1-C2 t ran sart icu lar screw m agn et ic reson an ce angiogram (MRA), TCVI, 136–137, 136f m agn et ic reson an ce im aging (MRI) cauda equin a syn drom e, 302, 303f cerebellar st roke or h em orrh age or su boccip it al t rau m a, 73–74, 75f cer vical burst fract u res, 201, 202f cer vical facet dislocat ion , 215 closed spin al t ract ion , 170 com bat-associated p en et rat ing sp ine inju r y, 402 CSDH, 17, 18t decom pressive cran iectom y, 54 in t racran ial in fect ion , 331, 332f, 347, 347f pediat ric TBI, 459 pit u it ar y apoplexy, 370, 372f spin al epidu ral com p ression , 288, 289f su rgical debridem en t of pen et rat ing h ead injuries, 120 th oracic fract u res, 239 th oracolum bar fract ures, 267 ven t ricular sh u n t m alfu n ct ion , 350, 350f MCA. See m iddle cerebral ar ter y m et ast at ic epidu ral spin al cord com pression (MESCC) an esth esia, 289–290 closu re, 300 et iologies of, 287 in ciden ce of, 286 in dicat ion s for su rger y, 288 path ophysiology of, 287 posterior an d p osterolateral p osit ion ing an d in cision , 292, 292f postop erat ive m an agem en t adjuvan t t reat m en ts, 300 m edicat ion , 300 m on itoring, 300 radiograph ic im aging, 300 preprocedu re con sid erat ion s m edicat ion , 288 radiograph ic im aging, 288, 289f, 290f presen t at ion of, 287 special con siderat ion s, 300–301 surgical approach es an terior, 291 gen eral prin ciples, 290–291 posterior, 291 t ran spedicu lar ap p roach operat ive procedure lam in ectom y, 297, 297f lateral an d ven t ral t um or rem oval, 299, 299f pedicu lectom y, 298, 298f m ethylp redn isolon e, for SCI, 215, 267, 302 m icrodialysis cath eter m on itoring closu re, 116 in dicat ion s for, 101, 458 operat ive procedu re bolt-t ype m on itor variat ion , 107, 107f m icrodialysis cath eter variat ion , 112 open ing of du ra an d leptom en inges, 108, 108f posit ion ing, 104, 104f
skin in cision , 105, 105f t w ist d rill cran iostom y, 106, 106f p ediat ric, 458, 459 p ostop erat ive m an agem en t fu rth er m an agem en t , 117–118 m edicat ion , 116 m on itoring, 116 radiograp h ic im aging, 116 p rep rocedu re con siderat ion s coagu lat ion param eters, 101 equ ip m en t availabilit y, 102 m edicat ion , 102 op erat ive eld p reparat ion , 102, 102f–103f radiograp h ic im aging, 101 special con siderat ion s, 118 m iddle cerebral ar ter y (MCA), t rau m at ic an eu r ysm of, 136 m idlin e su boccipit al cran iectom y, for in fraten torial ICH cran iectom y, 323–324, 323f–324f d ural open ing, 325, 325f h em atom a evacu at ion , 326, 326f p osit ion ing, 321, 321f skin in cision an d su bcu tan eou s dissect ion , 322, 322f m odi ed pterion al surgical ap proach , for cerebral con t usion s, 34 add ressing of con t u sion , 49, 49f an terior tem poral lobectom y, 50, 50f bur h ole p lacem en t , 46, 46f closing, 51 cran iotom y, 47, 47f d ural open ing, 48, 48f p osit ion ing, 43, 43f skin in cision , 44, 44f subcu t an eou s dissect ion , 45, 45f m on itoring. See invasive n eu rom on itoring MRA. See m agn et ic reson an ce angiogram MRI. See m agn et ic reson an ce im aging N n eck, zon es of, 138, 141f n eck t rau m a blun t TCVI. See ext racran ial blu n t TCVI p en et rat ing TCVI. See ext racran ial pen et rat ing TCVI n eurologic exam in at ion , for spin al fract u res, 238 n eu rom on itoring. See invasive n eu rom on itoring n eurovascu lar inju r y, t rau m at ic. See t rau m at ic cerebrovascu lar inju r y O occipit al decom pressive h em icran iectom y. See fron totem p oropariet al decom p ressive h em icran iectom y occipitocer vical arth rodesis, 470, 473 bon e graft , 478, 478f xat ion p oin t s an d rod an d w ire prep arat ion , 477, 477f p osit ion ing an d p rep arat ion , 474, 474f skin in cision , 475, 475f subcu tan eou s dissect ion , 476, 476f occipitocer vical xat ion , for ped iat ric cer vical sp in e injur y arth rodesis. See occipitocer vical arth rodesis C1 lateral m ass screw s, 479, 479f C2 pars screw, 480 C2 pedicle screw, 480, 480f C2 t ran slam in ar screw, 481, 481f p late, 479
501
502
Inde x occlusion , t rau m at ic vascular. See vascular occlusion odon toid fract ures C1- C2 lateral m ass fu sion w ith polyaxial screw s an d rods operat ive procedu re C1 screw t rajector y an d p lacem en t , 193, 193f C2 screw t rajector y an d p lacem en t , 194, 194f closing, 195 n al con st ruct , 195, 195f posit ion ing an d surgical site prep arat ion , 191, 191f t issue dissect ion an d exp osure, 192, 192f C1- C2 t ran sart icular screw op erat ive procedu re closing, 190 n al con st ruct , 190, 190f posit ion ing, 186, 186f screw t rajector y an d placem en t , 189, 189f surgical site prep arat ion , 187, 187f t issue dissect ion an d exp osure, 188, 188f in d icat ion s for surger y, 179 odon toid screw operat ive p rocedure cer vical dissect ion an d en t r y site prep arat ion , 182–183, 182f–183f closing, 185 com pleted con st ruct , 185, 185f posit ion ing, 181, 181f screw t rajector y an d placem en t , 184, 184f postoperat ive m an agem en t m edicat ion , 185, 190, 195 m onitoring, 185, 190, 195 preprocedu re con siderat ion s m edicat ion , 179 radiograph ic im aging, 179, 180f special con siderat ion s, 195–196 op en cran ial fract ures, 90, 99 orth oses for cer vical spin e inju ries, 490 for th oracic fract ures, 238 P p aren chym al brain m on itors. See invasive n eu rom on itoring p aren chym al injur y, p en et rat ing h ead inju ries w ith , 128–129, 128f–129f p ediat ric cer vical spin e inju r y an esth esia, 472 atlan toaxial arth rodesis, 470, 482 Brooks an d Jen kin s tech n iqu e, 482, 482f Gallie tech n iqu e, 483, 483f Harm s p osterior C1- C2 fu sion w ith p olyaxial screw an d rod xat ion , 486, 486f posterior C1-C2 t ran sart icular screw xat ion , 484–485, 484f closing, 489 in d icat ion s for su rger y, 470, 473, 482, 487 occipitocer vical xat ion ar th rodesis. See occipitocer vical ar th rodesis C1 lateral m ass screw s, 479, 479f C2 pars screw, 480 C2 pedicle screw, 480, 480f C2 t ran slam in ar screw, 481, 481f plate, 479 posit ion ing based on ap proach an terior cer vical, 472–473 posterior cer vical, 473
postoperat ive m an agem en t , 489, 489f preprocedu re con siderat ion s m edicat ion , 471 op erat ive eld an d em ergen cy room m an agem en t , 470–471, 471f radiograp h ic im aging, 471, 472f su rgical t im ing, 471 special con siderat ion s, 490 su baxial cer vical posterior arth rodesis for, 470, 487 in terspin ou s w iring arth rodesis, 487, 487f posterior arth rodesis w ith lateral m ass screw xat ion, 488, 488f pediat ric TBI closing, 469 gen eral su rgical prin cip les, 460 in dicat ion s for su rger y, 458 op erat ive procedu res cran iotom y, 461 decom p ressive cran iectom y, 461–462 dep ressed sku ll fract ure su rger y, 461 EVD, 460–461 grow ing sku ll fract u re repair. See grow ing sku ll fract u re rep air ICP an d oth er paren chym al brain m on itors, 460 postoperat ive m an agem en t m on itoring, 469 radiograp h ic im aging, 469, 469f w ou n d m an agem en t , 469 preprocedu re con siderat ion s an esth esia, 459–460 op erat ive eld preparat ion , 460 radiograp h ic im aging, 459, 459f pedicle can n u lat ion , for th oracolu m bar fract u res, 272–273, 272f pedicle screw s for occip itocer vical xat ion , 480, 480f for th oracic fract ures posterior decom pression , 248–249, 248f, 249f t ran sped icu lar corpectom y, 256, 256f for th oracolu m bar fract u res op en p osterior decom p ression , 274, 274f percut an eous p osterior decom p ression , 282, 282f pedicu lectom y, for spin al epidu ral com pression , 298, 298f PEEK. See polyeth ereth erketon e pen et rat ing h ead inju ries, 119 com bat-associated. See com bat cran ial operat ion s su rgical debrid em en t for. See su rgical debrid em en t of pen et rat ing h ead inju ries TCVI. See in t racran ial p en et rat ing TCVI pen et rat ing n eck inju ries, TCVI. See ext racran ial pen et rat ing TCVI pen et rat ing sp in e injuries, com bat-associated. See com batassociated pen et rat ing spin e inju r y percu t an eou s p osterior sp in al decom pression , for th oracolu m bar fract u res bon e t reph in e n eedle p lacem en t , 278–279, 278f closu re, 284 facet fu sion , 281, 281f gu id ew ire p lacem en t , 280, 280f posit ion ing an d pedicle t arget ing, 277, 277f rod placem en t an d deform it y correct ion , 283, 283f screw p lacem en t , 282, 282f perforat ing h ead inju ries, 119
Inde x pericallosal bran ch an eu r ysm s, 135 pericran ial ap elevat ion an d rot at ion of, 453, 453f h ar vest of, 337, 337f pericran ial graft , for com bat injuries, 395, 395f pet rocavern ou s segm en t an eur ysm s, 135 pit u it ar y apoplexy in dicat ion s for su rger y, 370 operat ive proced ure abdom in al fat graft , 383, 383f draping an d operat ing m icroscope, 375, 375f du ral in cision an d pit u it ar y t um or resect ion , 380, 380f uoroscopy, 373–374, 373f, 374f h em ost asis an d closu re, 382, 382f m u cosal ap, 376, 376f posit ion ing, 373, 373f sella exposu re, 378–379, 378f–379f sella oor recon st ru ct ion , 381, 381f sph en oid bon e iden t i cat ion , 377, 377f postop erat ive m an agem en t , 384 preprocedure con siderat ion s m edicat ion , 371 operat ive eld p rep arat ion , 371 radiographic im aging, 370, 371f, 372f special con siderat ion s, 384 PMMA. See polym ethylm eth acr ylate polyeth ereth erketon e (PEEK), for allop last ic cran iop last y, 436f, 439, 442–443 polym ethylm eth acr ylate (PMMA), for alloplast ic cran ioplast y, 438f, 439, 442 porou s polyethylen e, for alloplast ic cran ioplast y, 436f, 439, 442–443, 442f posterior sp in al decom p ression for th oracic fract ures, 241f, 242f lam in ectom y, 246, 246f ligam en t rem oval, 247, 247f pedicle screw en t r y poin t , 248, 248f pedicle screw placem en t , 249, 249f posit ion ing an d localizat ion , 243, 243f rod placem en t , 250, 250f skin , su bcut an eous, an d su bperiosteal dissect ion , 244, 244f spin ou s process rem oval, 245, 245f for th oracolum bar fract ures bon e graft ing, 276, 276f closu re, 284 decom pression , 271, 271f exposure, 270, 270f facetectom y an d pedicle can n ulat ion , 272–273, 272f percut an eous. See percu t an eou s posterior spin al decom pression posit ion ing, 269, 269f rod placem en t , 275, 275f t ap ping an d screw p lacem en t , 274, 274f posterior sp in al fusion , 216f operat ive proced ure closing, 225 decom pression an d redu ct ion , 220, 220f fu sion preparat ion , 221, 221f posit ion ing, 217, 217f posterolateral fu sion , 224, 224f
rod placem en t , 223, 223f screw placem en t , 222, 222f su bcu t an eou s dissect ion , 218–219, 218f, 219f p seudoan eu r ysm , 133 PSI. See com bat-associated penet rat ing spin e inju r y R radiograp h ic im aging alloplast ic cran ioplast y p ostop erat ive, 442 p reprocedu re, 424–425 bon e ap replacem en t p ostop erat ive, 422, 422f p reprocedu re, 412, 412f cau da equ in a syn drom e, p rep rocedu re, 302, 303f cerebellar st roke or h em orrh age p ostop erat ive, 88f, 89 p reop erat ive, 73–74, 75f cerebral con t u sion s p ostop erat ive, 51, 51f p reop erat ive, 33, 33f cer vical bu rst fract u res p ostop erat ive, 212, 212f p reprocedu re, 201, 202f cer vical facet dislocat ion p ostop erat ive, 234, 235f p reprocedu re, 215 ch ron ic su bdu ral h em atom a p ostop erat ive, 30, 30f, 31f p reop erat ive, 16–17, 17f, 18f, 18t closed spin al t ract ion p ostop erat ive, 176f, 177 p reprocedu re, 170, 171f com bat-associated p en et rat ing spin e inju r y, p rep rocedu re, 402 com bat cran ial operat ion s p ostop erat ive, 396, 396f p reprocedu re, 386, 387f d ecom pressive cran iectom y p ostop erat ive, 70, 71f p reop erat ive, 53–54, 54f d epressed skull fract ure elevat ion p ostop erat ive, 99, 99f p reop erat ive, 90, 91f epidu ral or su bd ural h em atom a p ostop erat ive, 14, 15f p reop erat ive, 2, 3f fron t al sin u s injuries p ostop erat ive, 456 p reprocedu re, 444, 445f grow ing skull fract u re rep air p ostop erat ive, 469, 469f p reprocedu re, 459, 459f ICH p ostop erat ive, 327, 327f, 328f p reprocedu re, 312, 312f, 313f, 320, 320f in t racran ial in fect ion p ostop erat ive, 347, 347f p reprocedu re, 331, 332f invasive n eurom on itoring p ostop erat ive, 116, 117f p reprocedu re, 101
503
504
Inde x radiograp h ic im aging (cont inued) odon toid fract ures, preprocedu re, 179, 180f pediat ric cer vical sp in e inju r y postoperat ive, 489, 489f preprocedure, 471, 472f pediat ric TBI, preprocedu re, 459, 459f pit u it ar y apoplexy, prep rocedu re, 370, 371f, 372f SjVO2 m on itor p osit ion veri cat ion , 115, 115f spin al epidural com pression postoperat ive, 300 preprocedure, 288, 289f, 290f suboccipit al t raum a postoperat ive, 88f, 89 preoperat ive, 73–74, 75f surgical d ebridem en t of pen et rat ing h ead inju ries postoperat ive, 131, 131f preoperat ive, 120, 121f t rau m at ic cerebrovascu lar inju r y (TCVI) postoperat ive, 151 preoperat ive, 136–137, 136f th oracic fract ures postoperat ive, 262, 262f, 263f preprocedure, 238–239 th oracolu m bar fract u res postoperat ive, 284, 284f preprocedure, 267, 267f t rau m at ic CSF rh in orrh ea rep air postoperat ive, 456 preprocedure, 444, 445f ven ous sin us injuries postoperat ive, 168, 168f preoperat ive, 153, 154f ven t ricular sh un t m alfun ct ion postoperat ive, 368, 368f preprocedure, 350, 350f, 351f reperfu sion , of TCVI, 137–138 rib h ead t rap door osteotom y, for th oracic fract u res, 255, 255f ribs, an atom y of, 237 S SCI. See spin al cord inju r y SCIWORA. See spin al cord inju ries w ith ou t radiograph ic abn orm alit y SDH. See su bdural h em atom a SEA. See spin al epidu ral abscess SEH. See spin al epidu ral h em atom a sella exposu re of, 378–379, 378f–379f reconst ruct ion of, 381, 381f sh un togram , for VS m alfun ct ion , 350–351 sh un t revision , for VS m alfu n ct ion distal cath eter revision , 360–364, 360f, 361f, 362f, 363f, 364f externalizing of dist al cath eter, 366, 366f posit ion ing an d prep arat ion, 353, 353f skin incision an d w ou n d dissect ion , 354–355, 354f–355f valve an d distal cath eter evalu at ion , 359, 359f ven t ricular cath eter p lacem en t , 358, 358f ven t ricular cath eter p lacem en t an d t u n n elling for extern al drain age, 365, 365f ven t ricular cath eter reser voir evalu at ion , 356, 356f ven t ricular cath eter revision , 357, 357f w ou nd closure, 365, 367, 367f
sh un t t ap, for VS m alfu n ct ion , 350 sin king scalp ap syn drom e, 71 sin u s inju ries fron t al. See fron t al sin u s inju ries ven ou s. See ven ou s sin u s inju ries sin u s in terposit ion graft of an terior on e-th ird su perior sagit t al sin u s, 161, 161f of posterior t w o-th irds su perior sagit t al sin u s, torcu lar h eroph ili, an d dom in an t t ran sverse sin u s, 167 sin u s ligat ion , of an terior on e-th ird su p erior sagit t al sin us, 159, 159f sin u s m u cosa, bu rn ing of, for fron t al sin u s su rger y, 451, 451f sin u s patch of an terior on e-th ird su perior sagit t al sin u s, 160, 160f of posterior t w o-th irds su perior sagit t al sin u s, torcu lar h eroph ili, an d dom in an t t ran sverse sin u s, 166, 166f sin u s repair, after dep ressed skull fract ure elevat ion , 97, 97f sin u s sten osis, after ven ous sin u s inju r y, 168 sin u s th rom bosis, after ven ou s sin u s inju r y, 168 SjVO2 m on itoring. See jugu lar ven ou s sat u rat ion m on itoring sku ll base recon st ru ct ion , for com bat inju ries, 395, 395f sku ll fract u res depressed. See d epressed sku ll fract u re elevat ion grow ing. See grow ing sku ll fract u re repair SLIC gu id elin es, 197, 197t sph enoid bon e, id en t i cat ion of, 377, 377f spin al cord, an atom y of, 237 spin al cord inju ries w ith ou t radiograph ic abn orm alit y (SCIWORA), 470, 490 spin al cord inju r y (SCI) com bat-associated, 398, 400f, 401f n eurologic exam in at ion, 238 pediat ric, 470 steroids for, 215, 239, 267, 302, 471 spin al decom p ression com bat-associated p en et rat ing spin e inju r y, 408, 408f posterior. See p osterior spin al decom p ression spin al ep idu ral abscess (SEA) an esth esia, 289–290 closu re, 300 et iologies of, 286 in ciden ce of, 286 in dicat ion s for su rger y, 288 lu m bar lam in ectom y operat ive procedu re lam in ectom y, 295, 295f n er ve root ret ract ion an d abscess rem oval, 296, 296f pathop hysiology of, 287 posterior an d posterolateral positioning an d incision, 292, 292f postoperat ive m an agem en t adjuvan t t reat m en t s, 300 m edicat ion , 300 m on itoring, 300 radiograp h ic im aging, 300 preprocedu re con siderat ion s m edicat ion , 288 radiograp h ic im aging, 288, 289f, 290f presen t at ion of, 287 special con siderat ion s, 300 su rgical app roach es an terior, 291 gen eral prin ciples, 290–291 posterior, 291
Inde x spin al epidu ral com p ression , m etast at ic. See m etast at ic epidu ral spin al cord com pression spin al epidu ral h em atom a (SEH) an esth esia, 289–290 closu re, 300 et iologies of, 286 in ciden ce of, 286 in dicat ion s for su rger y, 287 path ophysiology of, 287 posterior and p osterolateral posit ion ing an d incision , 292, 292f postoperat ive m an agem en t adjuvan t t reat m en t s, 300 m edicat ion , 300 m on itoring, 300 radiograph ic im aging, 300 preprocedu re con siderat ion s m edicat ion , 288 radiograph ic im aging, 288, 289f, 290f presen t at ion of, 287 special con siderat ion s, 300 su rgical approach es an terior, 291 gen eral prin ciples, 290–291 posterior, 291 th oracic lam in ectom y op erat ive proced ure h em atom a rem oval, 294, 294f lam in ectom y, 293, 293f spin al fract ures cer vical. See cer vical bu rst fract ures th oracic. See th oracic fract ures th oracolum bar. See th oracolu m bar fract u res spin al fusion an terior. See an terior sp in al fu sion posterior. See posterior spin al fu sion spin al inju r y com bat-associated. See com bat-associated pen et rat ing spin e injur y pediat ric. See p ediat ric cer vical spin e injur y spin al t ract ion , closed. See closed sp in al t ract ion spin ou s process rem oval, for th oracic fract ures, 245, 245f sten t ing of ext racran ial blu n t TCVI, 137–138, 139f of ext racran ial pen et rat ing TCVI, 138, 141f steroid s for CSDH, 31 for in t racran ial in fect ion , 333 for SCI, 215, 239, 267, 302, 471 st roke cerebellar. See cerebellar st roke or h em orrh age decom pressive cran iectom y for. See decom pressive cran iectom y spon t an eou s ICH cau sing. See in t racerebral h em orrh age su baxial cer vical posterior arth rodesis, 470, 487 in terspin ou s w iring arth rodesis, 487, 487f posterior arth rodesis w ith lateral m ass screw xat ion , 488, 488f su bdural em pyem a, 330 closu re, 347 in dicat ion s for su rger y, 331 operat ive procedu re bon e ap elevat ion , 339, 339f du ral closure, 344, 344f
d u ral op en ing, 341, 341f em pyem a rem oval, 342, 342f in cision , 336, 336f p ericran ial ap h ar vest , 337, 337f p osit ion ing, 334–335, 334f–335f tem poralis division an d bu r h ole placem en t , 338, 338f p ostop erat ive m an agem en t fu rth er m an agem en t , 348 m edicat ion , 347 m on itoring, 347 radiograp h ic im aging, 347, 347f p rep rocedu re con siderat ion s m edicat ion , 333 op erat ive eld p reparat ion , 333 radiograp h ic im aging, 331, 332f special con siderat ion s, 348 su bdu ral h em atom a (SDH) ch ron ic. See ch ron ic subd u ral h em atom a in dicat ion s for su rger y, 2, 458 operat ive p rocedu re bon e ap replacem en t , 12, 12f closing, 14 cran iotom y, 7, 7f d rain p lacem en t , 13, 13f d u ral closu re, 11, 11f d u ral op en ing, 9, 9f h em atom a evacu at ion , 10, 10f p osit ion ing, 4, 4f skin in cision , 5, 5f su bcu t an eou s dissect ion , 6, 6f p ediat ric, 458, 460 p en et rat ing h ead inju ries w ith , 129 p ostop erat ive m an agem en t m edicat ion , 14 m on itoring, 14 radiograp h ic im aging, 14, 15f p rep rocedu re con siderat ion s m edicat ion , 2 op erat ive eld p reparat ion , 2 radiograp h ic im aging, 2, 3f special con siderat ion s, 15 su boccip it al t rau m a closing, 88 in dicat ion s for su rger y, 73 operat ive p rocedu re bony exposu re, 79, 79f bu r h ole p lacem en t , 80, 80f cran iectom y, 81, 81f d ecom pression of in farcted brain , 85, 85f d u ral closu re, 87, 87f d u ral op en ing, 83, 83f epidu ral h em atom a evacu at ion , 82, 82f h em ost asis, 86, 86f in t racerebellar h em atom a evacuat ion , 84, 84f p osit ion ing, 76, 76f skin in cision , 77, 77f su bcu t an eou s dissect ion , 78, 78f p ostop erat ive m an agem en t m edicat ion , 89 m on itoring, 89 radiograp h ic im aging, 88f, 89 ven t ricu lostom y, 88
505
506
Inde x su boccipit al t rau m a (cont inued) preprocedu re con siderat ion s m edicat ion , 74 operat ive eld preparat ion , 74 posit ion ing, 74 radiograph ic im aging, 73–74, 75f ven t riculostom y, 74, 77, 77f su perior sagit t al sin u s inju ries an terior on e-th ird op erat ive procedu re cran iotom y, 157, 157f gen eral con siderat ion s, 154 posit ion ing, 155, 155f sin us in terposit ion graft , 161, 161f sin us ligat ion , 159, 159f sin us patch , 160, 160f skin in cision , 156, 156f t am pon ade, 158, 158f closing, 165 depressed skull fract u re elevat ion w ith , 97, 97f in d icat ion s for su rger y, 153 posterior t w o-third s operat ive procedu re cran iotom y, 164, 164f direct rep air, 165, 165f gen eral con siderat ion s, 154 posit ion ing, 162, 162f sin us in terposit ion graft , 167 sin us patch , 166, 166f skin in cision , 163, 163f t am pon ade, 165 postoperat ive m an agem en t m edicat ion , 168 m onitoring, 168 radiograph ic im aging, 168, 168f preprocedu re con siderat ion s m edicat ion , 153 operat ive eld preparat ion , 153–154 radiograph ic im aging, 153, 154f special con siderat ion s, 168 su ppu rat ive in t racran ial th rom boph lebit is, 348 su praten torial ICH closing, 320 fron tal cran iotom y operat ive procedu re cran iotom y, 316, 316f du ral open ing, 317, 317f h em atom a evacu at ion , 318–319, 318f, 319f posit ion ing an d skin in cision , 314, 314f subcu t an eous dissect ion , 315, 315f in d icat ion s for su rger y, 312 postoperat ive m an agem en t , 327, 327f, 328f preprocedu re con siderat ion s in it ial m an agem en t , 313 m edicat ion , 313 operat ive eld preparat ion , 313 radiograph ic im aging, 312, 312f, 313f special con siderat ion s, 327–329 su rgical d ebridem en t of pen et rat ing h ead inju ries closing, 131 in d icat ion s for, 119–120 operat ive p rocedure app roach to paren chym al inju r y, 128–129, 128f–129f bur h ole placem en t , 125, 125f
cran iotom y, 126, 126f dural op en ing, 127, 127f duraplast y, 130, 130f in cision p lan n ing, 123, 123f posit ion ing, 122, 122f su bcut an eous dissect ion , 124, 124f postop erat ive m an agem en t m edicat ion , 131 m on itoring, 131 radiograp h ic im aging, 131, 131f preprocedu re con siderat ion s gen eral, 120 m edicat ion , 120 op erat ive eld preparat ion , 120–121 radiograp h ic im aging, 120, 121f special con siderat ion s, 132 syn drom e of th e t reph in ed, 71 T tam pon ade, for ven ous sin u s inju ries an terior on e-th ird su p erior sagit t al sin us, 158, 158f posterior t w o-th irds su perior sagit t al sin u s, torcu lar h erop h ili, an d dom in an t t ran sverse sin us, 165 TBI. See t rau m at ic brain inju r y TCLIS. See Th oracolu m bar Inju r y Classi cat ion an d Severit y Score TCVI. See t rau m at ic cerebrovascu lar inju r y tem poralis dissect ion of, for allop last ic cran ioplast y, 433–434, 433f–434f t ran sposit ion of for alloplast ic cran iop last y, 441, 441f for bon e ap rep lacem en t , 420, 420f tem poral lobe con t u sion . See cerebral con t u sion s tem poral lobectom y, for cerebral con t usion , 50, 50f th oracic ep idu ral sp in al cord com pression , su rgical app roach es to, 291 th oracic fract u res closu re, 262 evalu at ion an d diagn osis, 237 n eu rologic exam in at ion , 238 physical sp in e exam in at ion , 238 in dicat ion s for con ser vat ive m an agem en t , 238 in dicat ion s for su rgical m an agem en t , 237–238 operat ive p rocedu re select ion gu idelin es, 239 posterior decom pression operat ive procedu re, 241f, 242f lam in ectom y, 246, 246f ligam en t rem oval, 247, 247f pedicle screw en t r y poin t , 248, 248f pedicle screw p lacem en t , 249, 249f posit ion ing an d localizat ion , 243, 243f rod placem en t , 250, 250f skin , su bcu t an eous, an d su bp eriosteal dissect ion , 244, 244f spin ou s process rem oval, 245, 245f postop erat ive m an agem en t m edicat ion , 262 m on itoring, 262 radiograp h ic im aging, 262, 262f, 263f preprocedu re con siderat ion s m edicat ion , 239 op erat ive eld preparat ion , 239–240 radiograp h ic im aging, 238–239 special con siderat ion s, 264
Inde x surgical approach es an terior, 240 posterior, 240 posterolateral, 240 t ran spedicu lar corp ectom y op erat ive procedu re, 251f corpectom y an d diskectom y, 254, 254f drilling, 253, 253f pedicle screw s, 256, 256f rem oval of facet com p lex, 252, 252f rib h ead t rap door osteotom y, 255, 255f t ran sth oracic ver tebrectom y op erat ive p rocedure, 257f dissect ion , 259, 259f fu sion an d in st ru m en t at ion , 261, 261f posit ion ing an d ap proach p lan n ing, 258, 258f vertebrectom y, 260, 260f th oracic sp in e, an atom y of, 237 th oracolum bar fract ures classi cat ion , 266–267, 267t in dicat ion s for su rger y, 267 open operat ive procedure bon e graft ing, 276, 276f closu re, 284 decom pression , 271, 271f exposure, 270, 270f facetectom y an d ped icle can n u lat ion , 272–273, 272f posit ion ing, 269, 269f rod placem en t , 275, 275f t apping an d screw p lacem en t , 274, 274f percutan eou s op erat ive procedu re bon e t reph in e n eedle placem en t , 278–279, 278f closu re, 284 facet fusion , 281, 281f guidew ire placem en t , 280, 280f posit ion ing an d p edicle t arget ing, 277, 277f rod placem en t an d deform it y correct ion , 283, 283f screw placem en t , 282, 282f postoperat ive m an agem en t m edicat ion , 284 m on itoring, 284 radiograph ic im aging, 284, 284f preprocedu re con siderat ion s m edicat ion , 267 operat ive eld p reparat ion , 268 radiograph ic im aging, 267, 267f su rgical m an agem en t , 267–268 special con siderat ion s, 284 Th oracolu m bar Inju r y Classi cat ion an d Severit y Score (TCLIS), 266–267, 267t th oracoscopy, for th oracic fract u res, 240 th oracotom y, for th oracic fract ures, 240 t itan ium m esh , for alloplast ic cran iop last y, 437f, 439, 442–443 t itan ium plate, for alloplast ic cran ioplast y, 437f, 439, 442–443 torcular h erop h ili injuries closing, 165 in dicat ion s for su rger y, 153 operat ive proced ure cran iotom y, 164, 164f direct repair, 165, 165f gen eral con siderat ions, 154 posit ion ing, 162, 162f sin u s in terposit ion graft , 167
sin us p atch , 166, 166f skin in cision , 163, 163f t am p on ade, 165 p ostop erat ive m an agem en t m edicat ion , 168 m on itoring, 168 radiograp h ic im aging, 168, 168f p rep rocedu re con siderat ion s m edicat ion , 153 op erat ive eld p reparat ion , 153–154 radiograp h ic im aging, 153, 154f special con siderat ion s, 168 t ran exam ic acid, for CSDH, 16, 31 t ran spedicu lar app roach for m etast at ic disease lam in ectom y, 297, 297f lateral an d vent ral t u m or rem oval, 299, 299f p edicu lectom y, 298, 298f t ran spedicu lar corp ectom y, for th oracic fract u res, 251f corpectom y an d diskectom y, 254, 254f d rilling, 253, 253f p edicle screw s, 256, 256f rem oval of facet com plex, 252, 252f rib h ead t rap door osteotom y, 255, 255f t ran sth oracic vertebrectom y, for th oracic fract u res, 257f d issect ion , 259, 259f fu sion an d in st ru m en t at ion , 261, 261f p osit ion ing an d ap proach plan n ing, 258, 258f vertebrectom y, 260, 260f t rau m a, su boccip ital. See su boccip ital t rau m a t rau m at ic brain inju r y (TBI) decom pressive cran iectom y for. See decom pressive cran iectom y invasive n eurom on itoring for, 101, 116–118 p ediat ric. See pediat ric TBI p en et rat ing. See p en et rat ing h ead inju ries t rau m at ic cerebrovascu lar inju r y (TCVI) in dicat ion s for su rger y, 133–136, 133t, 134f, 135f m an agem en t ext racran ial blun t , 137–138, 138f, 139f ext racran ial p en et rat ing. See ext racran ial p en et rat ing TCVI in t racran ial blu n t , 142, 142f, 143f in t racran ial p en et rat ing, 142, 143f, 144, 144f p ostop erat ive m an agem en t m ed icat ion , 151 m on itoring, 151 radiograph ic im aging, 151 p rep rocedu re con sid erat ion s, radiograph ic im aging, 136–137, 136f special con siderat ion s, 151 t rau m at ic CSF rh in orrh ea repair closing, 456 in dicat ion s for, 444 operat ive procedu re bicoron al in cision , 446, 446f cran ial bon e ap replacem en t , 455, 455f brin sealan t app licat ion , 454, 454f fragm en t rem oval an d cat alogu ing, 448, 448f fron ton asal du ct packing, 452, 452f fron ton asal du ct paten cy con rm at ion , 449, 449f p ericran ial ap elevat ion an d rot at ion , 453, 453f p osterior t able rem oval, 450, 450f
507
508
Inde x t rau m at ic CSF rh in orrh ea repair (cont inued) sin us m u cosa bu rn ing, 451, 451f subperiosteal dissect ion , 447, 447f postoperat ive m an agem en t , 456 preprocedu re con siderat ion s, 444, 445f special con siderat ion s, 456 t um or resect ion pit u it ar y t u m ors, 380, 380f spin al t um ors, 299, 299f t w ist drill cran iostom y for CSDH cath eter placem en t , 28, 28f closing, 29, 29f drilling, 27, 27f posit ion ing, 26, 26f postoperat ive m an agem en t , 29, 30f skin in cision , 26, 26f for in t racran ial m on itoring, 106, 106f U u n ilateral cran iectom y, for allop last ic cran ioplast y cran iectom y site preparat ion , 435, 435f im plan t t ypes, 436f–438f, 439 posit ion ing, 427, 427f skin in cision , 429, 429f subcu t an eous dissect ion , 430–432, 430f, 431f–432f tem poral defect repair, 440, 440f tem poralis m u scle dissect ion , 433–434, 433f–434f tem poralis t ran sp osit ion , 441, 441f V VAI. See ver tebral arter y inju r y vascular occlusion , t raum at ic en dovascular m an agem en t of, 137, 139f ind icat ion s for su rger y, 133–134 VB. See vertebral body ven ous air em bolism , ven ou s sin u s inju ries w ith , 153 ven ous sin us injuries an terior on e-th ird sup erior sagit t al sin us op erat ive procedure cran iotom y, 157, 157f gen eral con siderat ion s, 154 posit ion ing, 155, 155f sin us in terposit ion graft , 161, 161f sin us ligat ion , 159, 159f sin us patch , 160, 160f skin in cision , 156, 156f t am pon ade, 158, 158f closing, 165 depressed skull fract u res cau sing, 90, 99 ind icat ion s for su rger y, 153 posterior t w o-th ird s sup erior sagit t al sin u s, torcular h eroph ili, an d dom in an t t ran sverse sin u s op erat ive p roced u re cran iotom y, 164, 164f direct rep air, 165, 165f gen eral con siderat ion s, 154 posit ion ing, 162, 162f sin us in terposit ion graft , 167 sin us patch , 166, 166f skin in cision , 163, 163f t am pon ade, 165
postoperat ive m an agem en t m edicat ion , 168 m on itoring, 168 radiograp h ic im aging, 168, 168f preprocedu re con siderat ion s m edicat ion , 153 op erat ive eld preparat ion , 153–154 radiograp h ic im aging, 153, 154f special con siderat ion s, 168 ven t ricu lar drain age. See extern al ven t ricular drain ven t ricu lar sh u n t (VS) m alfu n ct ion in dicat ion s for su rger y, 349, 350f postoperat ive m an agem en t , 368, 368f preprocedu re con siderat ion s diagn ost ic im aging, 350, 350f, 351f invasive diagn ost ic p rocedu res, 350–351 m edicat ion , 351 op erat ive eld preparat ion , 351, 352f sh un t revision operat ive p rocedure dist al cath eter revision , 360–364, 360f, 361f, 362f, 363f, 364f extern alizing of dist al cath eter, 366, 366f posit ion ing an d preparat ion , 353, 353f skin in cision an d w ou n d dissect ion , 354–355, 354f–355f valve an d dist al cath eter evalu at ion , 359, 359f ven t ricu lar cath eter p lacem en t , 358, 358f ven t ricu lar cath eter p lacem en t an d t u n n elling for extern al drain age, 365, 365f ven t ricu lar cath eter reser voir evalu at ion , 356, 356f ven t ricu lar cath eter revision , 357, 357f w ou n d closu re, 365, 367, 367f special con siderat ion s, 368 ven t ricu lostom y, for cerebellar st roke or h em orrh age or su boccipit al t rau m a postoperat ive, 88 presu rgical, 74, 77, 77f ver tebral arter y inju r y (VAI) cer vical facet dislocat ion w ith , 234 t rau m at ic, 133–135, 138, 143f ver tebral body (VB), an atom y of, 237 ve r t eb re ct om y, t r a n st h ora cic. See t ra n st h or a cic ve r t eb re ct om y VS m alfu n ct ion . See ven t ricular sh u n t m alfu n ct ion W w arfarin , for TCVI, 137 X X-ray cer vical burst fract u res, 201 cer vical facet dislocat ion , 215, 234, 235f closed sp in al t ract ion , 176f, 177 com bat-associated pen et rat ing spin e inju r y, 402 CSDH, 16 pediat ric cer vical spin e inju r y, 471, 472f, 489, 489f pediat ric TBI, 459 SjVO2 m on itor p osit ion veri cat ion , 115, 115f th oracic fract u res, 238–239, 262, 262f, 263f th oracolu m bar fract u res, 267, 284, 284f ven t ricu lar sh u n t m alfu n ct ion , 350, 351f, 368