Rev. bras. ortop. vol.52 número5

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SOCIEDADE BRASILEIRA DE ORTOPEDIA E TRAUMATOLOGIA

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Original

Article

Stand-alone

lumbar

interbody

fusion

–

complications

and

perioperative

results

夽

Rodrigo

Amaral

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_,

_Ronaldo

_Ferreira

a

_,

_Luis

_Marchi

a,∗

,

Rubens

Jensen

a

,

Joes

Nogueira-Neto

a

_,

_Luiz

_Pimenta

a,b

a_Instituto_de_Patologia_da_Coluna_(IPC),_São_Paulo,_SP,_Brazil

b_University_of_California_San_Diego_(UCSD),_San_Diego,_United_States

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Articlehistory:

Received18August2016 Accepted6September2016 Availableonline4September2017

Keywords: Spine Spinalfusion Arthrodesis Lumbarvertebrae

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Objectives: Historically,anteriorlumbarinterbodyfusion(ALIF)wasrelated tohighrates ofintraoperativecomplicationsandadverseeventsrelatedtointerbodydevices.Inrecent decades,therehavebeentechnical adjustments,andcagesthataremoresuitablehave emerged.Theaimofthisstudyistoevaluatetheefficacyandcomplicationrateoftheuse ofstand-alonemini-ALIFusingaself-lockingcage.

Methods:Retrospective single centerstudy. Inclusion criteria:retroperitoneal mini-ALIF forsingle-levelfusion(L5S1);self-lockingcage;DDD/stenosisandgradeI spondylolisthe-sis.Exclusioncriteria:posteriorsupplementation,previousfusion/arthroplasty.Endpoints: surgerydata,intraoperativeandperioperativeadverseeventsrelatedbothtosurgicalaccess andtotheintersomaticdevice.

Results:Eighty-sevencaseswereenrolled.Mediansurgicaltimewas90min;medianblood losswas100mL.ThemedianlengthofstayintheICUwaszerodays;medianhospitalstay wasoneday.Tencaseshadanadverseevent(11.5%):fourmajoradverseevents(4.6%;3L bleeding;DVT;retroperitonealhaematoma;incisionalhernia),andsevenminorevents(8%; peritoneuminjury;minorvascularinjury;eventsrelatedtothecage).Nocasesofretrograde ejaculationwereobserved.Therewasimprovementinpain,physicalrestriction,andquality oflife(p<0.001).

Conclusions: Themini-ALIFprocedureperformedforsingle-levelfusionatthedistallumbar leveldemonstratedlowadverseeventratesrelatedtoboththesurgicalapproachandto theintersomaticdevice,withreducedhospitalstayandsatisfactoryperioperativeclinical results.

夽

PaperdevelopedattheInstitutodePatologiadaColuna(IPC),SãoPaulo,SP,Brazil.

∗ _{Corresponding}_author_.

E-mail:[email protected](L.Marchi).

http://dx.doi.org/10.1016/j.rboe.2017.08.016

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Palavras-chave: Colunavertebral Fusãoespinal Artrodese

Vértebraslombares

Objetivos: Historicamente,afusãointersomáticalombaranterior(ALIF)esteverelacionada aaltastaxasdecomplicac¸õesintraoperatóriaseeventosadversosrelacionadosaos dispos-itivosintercorporais.Nasúltimasdécadas,ocorreramajustestécnicosquepropiciaramo surgimentodecagesmaisadequadas.Esteestudotevecomoobjetivoavaliarascomplicac¸ões eeficáciadousodeviaúnicapormini-ALIFcomusodecageautobloqueante.

Métodos: Estudoretrospectivodecentroúnico.Critériosdeinclusão:mini-ALIF retroperi-toneal para a fusão de nível único (L5S1); cage autobloqueante; DDD/estenose e espondilolistesede baixograu(grauI_)._Critérios _de_exclusão: _{suplementac¸ão}_posterior; fusão/artroplastiaprévia.Foramanalisadosdadosdecirurgia,complicac¸õesintrae peri-operatóriasrelacionadasaoacessocirúrgicoeaodispositivointersomático.

Resultados: Foramincluídos87casos,todosnonívellombardistal.Medianadetempo cirúr-gico: 90min;mediana deperdasanguínea:100mL.Amedianadotempodeinternação na UTI foi zero dia; a mediana de internação hospitalar foi de um dia. Dez casos (11,5%)apresentarameventosadversos,quatromaiores(4,6%;sangramentode3L;TVP; haematoma retroperitoneal; hérnia incisional) e sete menores(8%; lesão de peritônio; lesãovascularmenor;ocorrênciasrelacionadasaoimplante).Nenhumcasodeejaculação retrógrada foi observado. Houve melhoriaem dor,restrição física equalidade de vida (p<0,001).

Conclusões: O procedimento mini-ALIF feito em um único nível distal lombar apre-sentou baixas taxas de eventos adversos intra e perioperatórios, tanto quanto à abordagem e ao dispositivo, reduzida estada hospitalar e bons resultados clínicos perioperatórios.

Introduction

Lumbar interbody fusion canbe performed through differ-ent accesses (anterior,anterolateral,lateral, transforaminal and posterior). The advantages of the anterior approach (anterior lumbar interbody fusion, ALIF) include the pos-sibility of disc space re-expansion, lumbar lordosis recov-ery, indirect decompression, prevention of damage to posterior structures (paravertebral and osteoligamentous muscle) and morbidity and immediate perioperative pain reduction.1–5

Theanteriorinterbodylumbarfusiontechniquewas ini-tiallyusedbyBurns6_and_Capener,7_developed_as_one_of_the predominanttechniquesforthetreatmentofdiscogenic lum-barpain.Historically, ALIFhasbeenlinkedtohighratesof intraoperativecomplications,becauseofthetransperitoneal pathwayandadverseeventsrelatedtofusiondevicesdueto lackofadequatecages.8–10

Recently, with the adaptation of surgical access tech-niques and better interbody devices, it has been possible to obtain satisfactory rates of complications and high fusion rates.11 _Thus, _it _may _be _advantageous _to _perform arthrodesiswithadequatecagesbyalesstraumaticanterior approach.

Theobjective ofthe present study was to evaluatethe complicationsandperioperativeresultsofmini-ALIFanterior

stand-alone interbody fusion surgery withthe use of self-lockingcageatL5S1level.

Materials

and

methods

Thisisaretrospectivestudywithdatacollectedprospectively fromasinglemedicalcenter.Itwassubmittedtoandapproved by the Research Ethics Committee (52909516.3.0000.5551). PatientsselectedhadundergoneALIFtechniquebythesame spine surgeryteamfrom 2009to2016.Inclusion: retroperi-tonealmini-ALIFforsingle-levelfusion;self-lockingALIFcage; degenerative disc disease (DDD, withor without stenosis), orlowgradespondylolisthesis(gradeI).Exclusion:posterior oranterioradditionalsupplementation;fusion/prior arthro-plasty; cages with angulation greater than 15 degrees of lordosis.

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Fig.1–ImagesrepresentinganteriorretroperitonealaccesstotheL5-S1discspace.(A)Abdominalincision;(B)passage throughtheabdominalmuscles;(C)identificationofthebifurcationofthegreatvesselsinfrontofthediscspaceofL5S1;(D) exposureoftheanteriorfaceoftheintervertebraldisc;(E)discectomyandpreparationofthediscspaceforarthrodesisand (F)interbodyimplantsecuredwithlockingscrewsintothediscspace.

analyzedintheperioperativeperiodanduptothreemonthsof follow-up.

Surgicaltechnique

Themodernsurgicaltechniqueofananterioraccesswiththe useofabluntpassagethroughtheabdominalmusculature, retroperitonealsurgicalapproach,anddirectviewtoaccess theL5S1discspacehasbeencalledmini-ALIF.Thepatientis placedinasupinepositiononastandardradiolucent surgi-caltable.Thedegreeoflumbarlordosisshouldbeobserved, andapadplacedunderthepatientatthelevelofthelumbar spinetoraiseit,whichnotonlyopenstheanteriorspaceto facilitatediscectomybutalsoallowseasierplacementofthe implantwithsomedegreeofangulation(lordosis).Allpatients underwenttheanteriorapproachtothelumbosacralspine.A mini-PfannenstielincisionwasusedtoaccessL5-S1level.

Bluntdissectionisusedtomobilize the anteriorsheath of the rectus abdominis muscle to access the retroperi-tonealspace.Palpationoflargevesselshelpspreventvascular lesions.Theuretershouldbeidentifiedtoavoidits inadver-tentdamage,andthisistypicallyfoundontheperitonealside oftheexposure.

Autostaticretractorsaredeeplyplaced,andattachedtoa deviceassembledonthesurgicaltabletokeeptheviewofthe spineinmidline.Theuseofcurare-likedrugsfacilitates expo-sureandensurescorrectpositioningoftheretractors.Forthe exposureofL5-S1space,thedisccanbenormallyaccessed belowthebifurcationofthelargevessels.Thetransverse seg-mentalarteriestothediscspaceorthearterialbranchesofthe aortaneedtobesecurelyligated.Iliolumbarveinscanalsobe thecauseofproblemsrelatedtobleeding.Themediansacral arteryanditsveinneedtobeligatedtoallowaccessbelowthe bifurcation.

Theexcessiveuseofelectrocauteryalongtheanterior lon-gitudinalligamentmustbeavoidedtopreventsympathetic hypogastricplexusinjury,whichmayresultinretrograde ejac-ulation. Theanterior longitudinalligament is thenopened withascalpel,andthecompleteremovaloftheintervertebral discwithcurettesisperformed.Theposteriorlongitudinal lig-amentismaintainedandthelateralringportionsareopened to the level that allows insertion of the interbody spacer implants.Followingextensivediscectomyandremovalofthe endplate,theintervertebralimplantsareimpactedand lock-ingscrewsarepassedthroughthecagestowardstheadjacent vertebralbodies.Illustrativeimagesofthesurgicalprocedure areshowninFigs.1and2.

Results

Weanalyzed 87cases (50female individuals,mean age 44 years,meanBMI26.6kg/m2_)._All_cases_were_at_the_most_distal lumbarlevel(L5S1orbetweenL5/L4andtransitionalvertebra). ThedataofthestudiedgroupareshowninTable1.Average casefollow-upwas46monthsaftersurgery(minimum3and maximum84months).

Informationregardingthesurgicalprocedureand hospi-taladmissionareshowninTable2.Meansurgicaltimewas 98min(SD 24; 40–150); medianblood loss100mL (SD 455; 50–3000);meantimeofadmissioninanICUwaszeroday(SD 0.3;0–1);medianhospitalstayofoneday(SD0.6;1–3).

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Fig.2–Imagesofintraoperativefluoroscopyshowingfinalpositioningoftheinterbodyspacer.(A)Lateralviewand(B) anteroposteriorviewevidencingthetitaniumspacerandthelockingscrewstowardstheadjacentvertebralbodies.

Table1–Demographicandpreoperativedata.

Total(n) 87

Age(years) 44±11

Gender(female) 50(64%)

BMI(kg/m2₎ _26.6_±_4.1

Levelstreated 87

Discdegenerativedisease 45(51%)

DDD+stenosis 19(22%)

Spondylolisthesis 16(18%)

Postdiscectomy 8(9%)

L5S1 81(93%)

L4TV 2(2%)

L5TV 4(4%)

BMI,bodymassindex;DDD,discdegenerativedisease.

Valuesshowninmedian±standarddeviationorinabsolute num-ber(andpercentage).

Table2–Surgicalandperioperativedata.

Duration 90(98)±24min

Bloodloss 100(171)±455mL

ICUadmission 0(0.2)±0.2dia

Hospitaladmission 1.5(1.6)±0.6dia

Valuesshowninmedian(mean)±standarddeviation.

controlledlesion).Postoperativeeventswereone(1.1%)deep veinthrombosis,one(1.1%)retroperitonealhaematoma (addi-tional surgery required for drainage), one (1.1%) incisional hernia (requiredsurgical repair),and one (1.1%)superficial intraoperativewoundinfection.Therewasnocaseof retro-gradeejaculationinthisseries.Regardingthetwocases(2.3%) ofpostoperativeeventsrelatedtotheimplant,wereportone caseofsinkingandoneofpoorpositioning.Nocasesof expul-sionormigrationoftheimplantwereobserved.Therewereno casesofdeath.

Short-termclinicalresultsshowedastatisticallysignificant clinical improvement inthe cases treated. Pain symptoms

Table3–Adverseevents.

INTRAOP Vascular

Venousdamage(1a₎ ₂₍₁a₎ _2%

Arterialdamage 0 0%

Accidentalopeningoftheperitoneum 2 2%

Viscerallesion 0 0%

PERIOP Infection

Superficial 1 1%

Deep 0 0%

DVTa ₁a _1%

Retroperitonealhematomaa ₁a _1%

Incisionalherniaa ₁a _1%

Retrogradeejaculation 0 0%

Implant 2 2%

TOTAL 10 11%

Majoradverseevents 4 5%

Minoradverseevents 7 8%

Valuesshowninabsolutenumbersandpercentage.

a _Major_adverse_events.

Table4–Short-termclinicalresults.

Preop 1week 6weeks 3months

BackVAS 7.4 4.0a _3.7a _4.2a

LowerlimbsVAS 5.1 3a _2.9a _2.8a

ODI 44 39 34a ₃₁a

EQ-5D 0.59 0.65 0.70a _0.76a

Valuesshowninmean.

a _{Statistically}_lower_than_the_preoperative_value.

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improvementinsymptomsirradiatedtothelowerlimbs.The ODIscaleshoweda30%improvementinphysicalrestraint, anda29%improvementinqualityoflife.

Discussion

Thisstudy evaluated theuse ofthe mini-ALIF stand-alone approachregardingitscomplicationsanditsintraand peri-operativeresults.An11%rateofadverseevents(minorand major) with only 4% of major adverse events was found, whichresultedinreducedhospitalstay(average1.6days)and improvementofpainafteraweekofsurgery.Itisworth men-tioningthatthepresentstudy analyzedonlycaseswithout previousarthrodesisorinterbodysurgery,andonlyinthelast mobilelevel ofthespine(L5S1);this isthetechnically less challenginglevel,withfasteraccess(about20min)andthat potentiallyleadstofewercomplications.12

Theoverloadofsegmentsadjacenttoafusionisduetopoor alignmentinthesagittalplane,13_procedures_that_cause pos-teriordestabilization(damage tothe paravertebralmuscles andosteoligamentarystructures),14_and_violation_of_the_upper articularfacetsbytheshaftandscrews(kickingspine).15_The stand-aloneoption (withno furthersupplementation)with onlyimpactedorthreadedcagesinthediscspacehasshown manyflawsinthehistoryofspinalsurgery.8,16_Currently,_the traditionaloptionsforinstrumentationinALIFshortfusions are cage and transpedicular screws or cage and anterior plate.

The most modern form of instrumentation in ALIF is the stand-alone option with self-locking cages. The great advantage of this option would be the possibility to per-form the procedure through an anterior approach, in a stand-alone procedure, without injury or iatrogenesis of the posterior elements of the spine. Thus, the procedure becomesless invasiveand allowsthe patient the opportu-nityoflowperioperativemorbidityandrapidpostoperative mobilization.1,17

Unliketheoldstand-aloneoption,self-lockingspacersnow provideverysatisfactorybiomechanicalstability,with charac-teristicsthataresimilartoconstructionwithtranspedicular screws15,18,19 _and _different _from _only _impacted _cages.20 Obviously,theuseofthestand-aloneoptionshouldbe recom-mendedforlessunstablelumbarlevels,itmayeveninclude spondylolisthesis,21–24 _but_in_cases_with_bone_failures_(such asparslysis),theymaygenerateanabnormalmovement,and resultinarthrodesisfailure.25

ThedisadvantagesofALIFarerelatedtopossibleadverse eventsrelatedtoperitonealandretroperitonealstructures.In Brazilandinothercountriestheaccesstotheintervertebral discinanALIFisusuallyobtainedbyanaccesssurgeon (gen-eralorvascularsurgeon)26_in_order_to_reduce_the_possibility_of intraandperioperativecomplications.However,thispractice isnotmandatoryanddependsonwhetherthesurgeonhas thetrainingandtheabilitytodoso.Historically,theEuropean schoolofspinesurgeryhasabasictrainingforanterioraccess surgeries,27_and_the_American_school_is_beginning_to_embark onthispractice.ThisfactisevidencedbyJarretetal.28_in_an articlethatevaluatestheincidenceofcomplicationsinthe presenceorabsenceofaccesssurgeonsinspinesurgeries.No

differenceswereobserved.Thisshowsthatitdependsaloton thespinesurgeon’sexperienceandtraining.

Thevascularlesionsarepotentiallyamongthemostsevere intraoperativecomplications.Theyare consideredtobethe mostdevastatingcomplicationswithaninjuryratereported intheliteratureof1–40%,12,26,27,29_depending_on_the experi-enceofthegroupandthetypeofcasetreated;occurrences atL4L5levelaremorefrequent.30_In_this_study,_with_access onlytoL5S1,wenoted2.3%ofvascularlesionsobserved dur-ingsurgery,andprobablyonemoreeventnotobservedduring the procedure(total3.4%),but thatled toaretroperitoneal haematomanoticedsomedaysaftersurgery.Arteriallesions occurlessfrequentlythanvenouslesions,andthemost com-montypesofvascularinjuryarelacerationoftheiliacvein, inferiorvenacavaandileolumbarvein.Notallvascularlesions aresevere,andsomeofthemcanbesimplysolvedduringthe procedure, asweobservedwithminorlesionsinourstudy. InthearticlebyQuraishietal.,27_in_which_there_were_24/304 (7.8%)vascularproblemsofdifferentmagnitudes,9/304(3% ofthetotalor38%ofthelesions)thepresenceofavascular surgeonwasrequired.

Someattitudescanhelpavoidinginjuries,suchastheuse ofacurvedhaemostaticforcepswithasmallpieceofgauze or cotton woolon its tip. Thisforceps isused atthe time ofdissectionoftheanteriorlongitudinalligamentanddisc, forbettervisualizationofthediscspace.Themediansacral arteryandveinaredividedwithvascularclips,orligated.12 Oneofthepossibleadverseeventsisthatofretrograde ejac-ulationifthereisupperhypogastricplexusinjury.Although being feared, the reportedincidenceis low,as observedin thisstudyandintheliterature,0.1–8%ofthecases, depend-ing onthe techniqueused.12_With_a_more_refined_exposure technique,andcurrentlylessuseofelectrocautery,therateof retrogradeejaculationisthelowestobservedinthehistoryof spinalsurgery.Althoughpossible,incisionalherniasarerare complicationsifameticulousclosureinplanesisperformed afterthemini-ALIF.12

Conclusion

The procedure oflumbar interbody arthrodesisata single lumbardistallevelviaananteriormini-openaccess demon-stratedlowratesofadverseevents,bothregardingthesurgical approach and the interbody device. Theperioperativedata showedashorterhospitalization,rareuseofICU,and good improvement of clinical parameters and quality of life. A surgicalgroupwithprofessionalswithaccessexperienceis necessarytokeepthereproducibilityofthesurgicalprocedure.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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