www.bjorl.org
Brazilian
Journal
of
OTORHINOLARYNGOLOGY
ORIGINAL
ARTICLE
Endoscopic
endonasal
double
flap
technique
for
reconstruction
of
large
anterior
skull
base
defects:
technical
note
夽
Ricardo
Landini
Lutaif
Dolci
a,∗,
Alexandre
Bossi
Todeschini
b,
Américo
Rubens
Leite
dos
Santos
b,
Paulo
Roberto
Lazarini
aaSantaCasadeMisericórdiadeSãoPaulo,FaculdadedeCiênciasMédicas,DepartamentodeOtorrinolaringologia,SãoPaulo,SP,
Brazil
bSantaCasadeMisericórdiadeSãoPaulo,FaculdadedeCiênciasMédicas,DepartamentodeCirurgia,Disciplinade
Neurocirurgia,SãoPaulo,SP,Brazil
Received10January2018;accepted19March2018 Availableonline19April2018
KEYWORDS Cerebrospinalfluid leak; Skullbase; Meningioma Abstract
Introduction:Oneofthemainconcernsinendoscopicendonasalapproachestotheskullbase hasbeenthehighincidenceandmorbidityassociatedwithcerebrospinalfluidleaks.The intro-ductionandroutineuseofvascularizedflapsallowedamarkeddecreaseinthiscomplication followedbyagreatexpansionintheindicationsandtechniquesusedinendoscopicendonasal approaches,extendingtodefectsfromhugetumoursandpreviouslyinaccessibleareasofthe skullbase.
Objective: Describethetechniqueofperformingendoscopicdoubleflapmulti-layered recon-structionoftheanteriorskullbasewithoutcraniotomy.
Methods:Step bystep description oftheendoscopicdoubleflap technique(nasoseptaland pericranialvascularizedflapsandfascialatafreegraft)asusedandillustratedintwopatients withanolfactorygroovemeningiomawhounderwentanendoscopicapproach.
Results:Bothpatientsachievedagrosstotalresection:subsequentreconstructionofthe ante-riorskullbasewasperformedwiththenasoseptalandpericranialflapsonlayandafascialata freegraftinlay.Bothpatientsshowedanexcellentrecovery,nosignsofcerebrospinalfluidleak, meningitis,flapnecrosis,chronicmeningealorsinonasalinflammationorcerebralherniation havingdeveloped.
夽 Pleasecitethisarticleas:DolciRL,TodeschiniAB,dosSantosAR,LazariniPR.Endoscopicendonasaldoubleflaptechniquefor
recon-structionoflargeanteriorskullbasedefects:technicalnote.BrazJOtorhinolaryngol.2019;85:427---34.
∗Correspondingauthor.
E-mail:landini37@hotmail.com(R.L.Dolci).
PeerReviewundertheresponsibilityofAssociac¸ãoBrasileiradeOtorrinolaringologiaeCirurgiaCérvico-Facial.
https://doi.org/10.1016/j.bjorl.2018.03.008
1808-8694/©2018Associac¸˜aoBrasileiradeOtorrinolaringologiaeCirurgiaC´ervico-Facial.PublishedbyElsevierEditoraLtda.Thisisanopen accessarticleundertheCCBYlicense(http://creativecommons.org/licenses/by/4.0/).
Conclusion:Thisendoscopicdoubleflaptechniquewehavedescribedisaviable,versatileand safeoptionforanteriorskullbasereconstructions,decreasingtheincidenceofcomplications inendoscopicendonasalapproaches.
© 2018 Associac¸˜ao Brasileira de Otorrinolaringologia e Cirurgia C´ervico-Facial. Published by Elsevier Editora Ltda. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/). PALAVRAS-CHAVE Vazamentodelíquido cefalorraquidiano; Basedocrânio; Meningioma
Técnicaendoscópicaendonasalutilizandoduploretalhoparareconstruc¸ãode grandesdefeitosdabaseanteriordocrânio:notatécnica
Resumo
Introduc¸ão:Umadasprincipaispreocupac¸õesemabordagensendoscópicasendonasaisdabase docrâniotemsidoaaltaincidênciaemorbidadeassociadaafístulasliquóricas.Aintroduc¸ãoeo usorotineiroderetalhosvascularizadospermitiramumaacentuadareduc¸ãodessacomplicac¸ão, seguidaporumagrandeexpansãonasindicac¸õesetécnicasutilizadasnasabordagens endoscópi-casendonasais,incluindograndestumoreseáreasanteriormenteinacessíveisdabasedocrânio. Objetivo:Descrever a técnica cirúrgica realizando uma reconstruc¸ão endoscópica multica-madasdabaseanteriordocrâniocomduploretalho,semcraniotomia.
Método: Descric¸ãopassoapassodatécnicaendoscópicacomduploretalho(retalhos vascu-larizadosnasoseptalepericranianoeenxertolivredefascialata),utilizadoseilustradosem doispacientescommeningiomadosulcoolfatóriosubmetidosàcirurgia porviaendoscópica endonasal.
Resultados: Em ambos os pacientes procedeu-se ressecc¸ão total macroscópica seguido de reconstruc¸ãodabase anteriordo crâniocom osretalhos nasoseptale pericraniano onlaye enxerto livre de fáscia lata inlay. Os pacientes apresentaram uma excelente recuperac¸ão, semsinaisdefístulaliquórica, meningite,necrosedo retalho,inflamac¸ãomeníngeacrônica ousinonasalouhérniacerebral.
Conclusão:A técnica endoscópicade duploretalho, como descrita, trata-se deuma opc¸ão viável,versátileseguraparaasreconstruc¸õesdabaseanteriordocrânio,diminuindoa incidên-ciadecomplicac¸õesemabordagenscirúrgicasendoscópicasendonasais.
© 2018 Associac¸˜ao Brasileira de Otorrinolaringologia e Cirurgia C´ervico-Facial. Publicado por Elsevier Editora Ltda. Este ´e um artigo Open Access sob uma licenc¸a CC BY (http:// creativecommons.org/licenses/by/4.0/).
Introduction
Differenttypesofvascularizedflaps,nasalandextranasal,
havebeendescribedfordifferentobjectives,suchasfacial
reconstruction,orbitalelevation,septalperforation
correc-tions and, mainly, for the closure of cerebrospinal fluid
(CSF) leaks during and postoperatively of the endoscopic
endonasalskullbasesurgery,allowingforfewer
technique-related complications and an impressive growth of this
technique.1---6Thechoiceofvascularizedflaptobeusedis
relatedtothesizeoftheexpectedskullbasedefect,
previ-oussurgeries,tumourtype(benignormalignant),location
andtumourextensiontopossibledonorareas.4
Themorewidelyusednasalflapsarethe(1)nasoseptal,
(2)inferiorturbinate, (3)middleturbinate and(4)lateral
wall.Theextra-nasalflapsarethe(1)pericranial,(2)
tem-poroparietalfasciaand(3)palatal.2,4,7---11
The nasoseptal flap can be considered a milestone in
thedevelopmentandgrowthof theendoscopicendonasal
surgeryoftheskullbaseandithasbecometheworkhorse
toclosetheCSFleaksinherenttothistechnique.Itiseasy
toobtain andversatile,reachingfromthe clivalregionto
theanteriorfossa.1,4
However,therearesome tumoursandapproaches that
createanextensiveskullbasedefectthatisnotpossibleto
beclosedusingonlythenasoseptalflap,requiringeithera
freegraftorasecondvascularizedflap.
Thevascularizedflapwithbestresultsforanteriorskull
base defects is the extra nasal pericranial flap that
usu-allyrequiresacraniotomy.Thisstudyaimstoshowanovel
techniquefortheuseofthepericranialflapwithouta
cran-iotomy,alongsidethenasoseptalflapandafreefascialata
graft, for the correction of extensive anterior skull base
defects,yieldingalowercomplicationrate.10,12,13
Methods
We retrospectivelyreviewedthe chartinformationoftwo
patients with an olfactory groove meningioma diagnosis
whounderwentendoscopicendonasalapproachfortumour
resectionandskullbasereconstructionusingthetechnique
wewilloutline,usingdoublevascularizedflaps(the
nasosep-tal and the pericranial) and a free fascia lata graft. This
studywasreviewedandapprovedbyourinstitution’sEthics
Patient1
Female,49yearsold,complainingof diminishedolfaction
andcognitivechanges(periodsofdisorientationand
confu-sionandmemoryimpairment).Magneticresonanceimaging
(MRI)showedalargeintracranialmass,withdural
attach-mentandtailontopofthecribriformplate,occupyingmost
ofthe anteriorskullbase withsignificantmass effectand
oedemainbothfrontallobes(Fig.1).
Patient2
Male, 39years old,complaining of mild tomoderate
fre-quentheadachesanddiminishedolfaction.MRIshowedan
intracranialmasswithduralattachmentontopofthe
cribri-formplatewithboneinvasionoftheplateandtheethmoid
(Fig.2).
Operative
technique
Thenasoseptalflap
In both cases thenasoseptal flapwasharvested from the
right side, employing the standard upper incisionis with
care to preserve the superior portion (about 15mm) of
the septalmucosa, from itsposterior margin tothe
mid-dle turbinate, in orderto preserve thedelicate olfactory
nerve filaments present in this area and, therefore, the
patient’s olfaction.1,3 However, in both cases a
transcrib-riformapproachwasplanned,whichleadstopostoperative
anosmia.Theupperincisionwasmadehigher,withoutcare
fortheolfactorymucosa,inordertomaximizetheavailable
areaoftheflap.Theinferiorincisionwasalsoloweredtothe
floorofthenasalcavitywiththesameobjective.
Inaddition,wasremovedthevomerandthe
perpendic-ularplateof theethmoid.Toprotecttheexposedseptum
cartilage and toreduce postoperative crusting, a reverse
flapusingthecontralateralmucosawasfashioned.
Tumourremoval
Theanteriorandposteriorethmoidalarterieswereligated
andcutbilaterally,interruptingpartofthearterialsupplyto
thetumour,reducingintraoperativebleeding.Anendonasal
craniectomywasperformedintheroofofthenasalcavities,
includingtheremovalofthecribriformplate,foragreater
reachandtumourexposure.Thelimitsoftheopening are
theposteriorwallofthefrontalsinus(anterior),theplanum
sphenoidale(posterior)andthetransitionbetweenthe
crib-riformplateandthefoveaethmoidalis(lateral).Next,the
duramaterwasopenedandthetumourdebulked,allowing
easiermanipulationoftheremainingtumoursoitcouldbe
carefullyseparatedfromthenormalbrain,usinga
biman-ualdissectiontechniquebythesurgeonwiththeassistant
responsiblefor handling theendoscope and,when
neces-sary,irrigationor suction of thecavity (4-hand endonasal
surgery).Thistechniqueallowsagrosstotalremovalofthe
tumouranditscapsule,whilerespectingandpreservingthe
planeof dissectionprovidedby thearachnoid membrane,
thatprotectsthedelicateperforatingvasaandnervous
tis-sue. In both cases, a gross total resection was achieved
Figure1 Patient1,female,49yearsold.(A,B)PreoperativeMRIwithoutacontrastshowingalargemassintheanteriorfossawith masseffect.Theanteriorcerebralarteriesaredisplacedposteriorlyandthereisinvasionoftheanteriorandposteriorethmoid. (C,D)Postoperative4yearsMRIwithcontrast,showinggrosstotalresectionandnosignsoftumourrecurrenceorbrainherniation. Bothflapscanbeseenwithgadoliniumenhancementandpreservationofthepediclesandviabilityoftheendoscopicdoubleflap.
Figure2 Patient2,male,39yearsold.(A,B)PreoperativeMRIwithcontrastshowinganintracranialmasswithduralattachment andinvasionoftheanteriorandposteriorethmoid.(C,D)Postoperative1yearMRIwithcontrast,showinggrosstotalresectionand nosignsoftumourrecurrenceorbrainherniation.Bothflapscanbeseenwithgadoliniumenhancementandpreservationofthe pediclesandviabilityoftheendoscopicdoubleflap.
althoughthe preservationof theolfactory nerves wasnot
possible.
Thepericranialflap
Abicoronalincisionwasperformed, approximately1.5cm
anteriortoeachexternalacousticmeatusandcrossingthe
scalpposteriorly tothe coronal sutures. After this initial
incision, the skin flap is elevated anteriorly up to about
10mmabovetheorbitalrim,throughthelooseareolarlayer,
atypicallyavascularlayerreducingbleedingandbloodloss.
Thepericraniumandtemporalmuscleswerekeptattached
totheskullatthistime.
Careshould betaken toavoid separating theskin flap
andthe pericraniumbeyond 10mm abovethe orbital rim
due tothe risk of injury the neurovascular supply of the
skin and pericranium. These are supplied by the
superfi-cialbranchesofthesupra-orbitalandsupratrochlearnerves
and the supra-orbital and supratrochlear arteries and its
branches(superficialbranchestotheskinanddeepbranches
totheflap).14Inordertoavoidmuscleatrophy,reduce
post-operativepainandaproduceabetteraestheticoutcomewe
avoidelevatingorcuttingthetemporalismuscles.
Oncetheposteriorextentofthepericranialflapis
satis-factory,lateral incisionsaremade immediatelyabovethe
superficial temporal lines and connected posteriorly. The
pericranialflap is then elevated anteriorly from the skull
allthewaytotheorbitalrims,leavingthelast10mmstill
attachedtotheskin(bothskinanpericraniumareelevated
fromtheskulltogetherbeyondthispoint).
Beinganextranasalflapitisnecessarytomakean
open-ingintheglabella,intheanteriorwallofthefrontalsinus,
about 20mm×5mm,sothe flapcanreachthenasal
cav-itythroughthefrontalsinus.ADrafIII(modifiedendoscopic
Lothrop) must be done to communicate the frontal sinus
andremoveanyinternalsepta,allowingthepassageofthe
pericranialflapposteriorlytotheskullbaseandnasalcavity.
Doingthistechnique,itisfeasibletoavoidanyinfectionand
mucocele,keepingthefrontalsinuswidelyopentoremove
themucosainside(Figs.3and4).
Ifnecessary, lateralincisionsat theanteriorportionof
theflapcanbeperformed toeaseitspassagethroughthe
narrow windowopenedin theanteriorwall ofthe frontal
sinus.However,thesemustbedoneverycarefullytoavoid
injurytothevascularpedicleoftheflap.
Skullbasereconstruction
Initially,afreefascialatagraftwasharvestedfromtheright
thighandplacedinlayat theskullbaseopening, covering
allthedefect.Then,thepericranialflap,comingfromthe
frontalsinus,wasplacedonlayovertheanteriorfossa,from
theposterior wallofthefrontal sinusheading posteriorly,
Figure3 Stepbystepofadissectionshowinghowtoraisingthepericranialflap,thepictureswasdoneinacadaver.(A)Bicoronal incisionwasperformed,approximately1.5cmanteriortoeachexternalacousticmeatusandcrossingthescalpposteriorlytothe coronalsutures.(B)Afterthisinitialincision,theskinflapiselevatedanteriorlyuptoabout10mmabovetheorbitalrim,through thelooseareolarlayer,atypicallyavascularlayerreducingbleedingandbloodloss.Thepericraniumandtemporalmuscleswere keptadheredtotheskullatthistime.(C)Inalateralview,itisfeasibletovisualizetheleftsuperficialtemporalarteryandthe fasciaexposed.(D,E)Thisflapissuppliedbythesupra-orbitalandsupratrochleararteriesanditsbranches(superficialbranchesto theskinanddeepbranchestotheflap),inthepictureisemphasizedthesupraorbitalnerve.Thepericranialflapisthenelevated anteriorlyfromtheskullallthewaytotheorbitalrims,leavingthelast10mmadheredtotheskin(bothskinanpericraniumare elevatedfromtheskulltogetherbeyondthispoint).(F)Inthenose,itisnecessarytopreparethewaytoreceivetheflapandavoid anyinfectionorMucoceleposteriorly,soitismandatorytoperformaDrafIII(modifiedendoscopicLothrop)allowingthepassage ofthepericranialflapposteriorlytotheskullbasetothenasalcavity.TheDrafIIIisthecommunicationoftherightandleftfrontal sinusandremovinganyinternalssepta.
Figure4 Intraoperative pictureshowing the ‘window’ cre-atedintheanteriorwallofthefrontalsinusforpassageofthe pericranialflap.
anteriorlyoverthedefect,Lastly,thepericranialflapwith
fibrinsealantwasapplied.Thatway,amulti-layered
recon-structionwasachievedwithadouble-vascularizedflapover
thedefect,witheachflapbeingreinforcedbytheotherat
itsfreemargin(Fig.5).Wehadnotusedthelumbardrain
inthosecases.
Results
Bothpatients underwent successfulendoscopic endonasal
transcribriformapproacheswithgrosstotalresectionanda
doubleflapanteriorskullbasereconstructionusingafree
fascialatagraftinlay,thepericranialflap(harvestedwitha
bicoronalincisionandinsertedtothenasalcavitythrough
a window in the anterior wall of the frontal sinus) and
the nasoseptal flap, both covering the defect, forming a
3-layeredreconstructionwithadoublevascularizedflap.
NeitherpatienthadpostoperativeCSFleakormeningitis.
Duringfollowup(4yearsforpatient1and1yearforpatient
2)synechiae,epistaxisormucoceledidnotdevelopandboth
flapsshowedgoodviabilitywithoutsignsofnecrosis.
Both patients had anosmia after the procedure as
expected for a transcribriforme approach, but were free
of recurrence and without any signs of brain herniation
through the bone defect on magnetic resonance imaging
Figure5 Graphicrepresentationofthedoubleflaptechnique withthepericranialandnasoseptalflapsforreconstructionof theanteriorskullbase.(A)Sagitalview.Thepericranialflap, afterbeingharvestedwithabicoronalincision,isintroducedto thesinonasalcavitythrougha‘window’intheanteriorwallof thefrontalsinusreachingtheplanumsphenoidaleandthesella. (B)Sagitalview.Nasoseptalflapharvestedfromthemedialwall ofthenasalcavity,preservingitsvascularpedicle,andplaced overtheanteriorskullbasedefect.(C)Sagitalview.Both per-icranial andnasoseptal flaps overlayingand reinforcingeach other’sweakpointsforthereconstructionoftheanteriorskull base, reducing the risk of CSF leak or brain herniation. (D) Tridimensionalviewwithasagittalmidlinesection.Skullbase defectfromtheposteriorwallofthefrontalsinustotheplanum sphenoidale,reconstructed using the endoscopic double flap techniquewiththepericranialandnasoseptalflapsreinforcing eachother,improvingthemechanicalsupportforintracranial structuresandamoreeffectivebarriertoCSF.
Discussion
The endoscopic endonasal approach for olfactory grooves
meningiomas has many advantages over traditional
cran-iotomies.Helpful is early devascularisationof the tumour
with the bilateral ligation of the anterior and posterior
ethmoid arteries, which are responsible for the arterial
irrigationofthetumour.15,16
Alowerrecurrencerateoccurredthankstoatrue
Simp-sonGrade1resection,17withremovaloftheaffectedbone
andduramater.Thesehavetoberemovedinordertoreach
thetumourviatheendoscopicapproachandwhenpreserved
during traditional craniotomiesthey are frequent tumour
recurrencelocations.18,19 AsshownbyNandaetal.,in458
intracranialmeningiomasofdifferentlocationsduringa20
yearsfollowup,whenaSimpsonGrade1resectionwas
pos-sibletherecurrenceratewas5%andthosewithaSimpson
Grade2resection,recurrencewas22%.20
Thereisnoneedforbrainretraction,oncethe
craniec-tomyandduralopeningareperformeddirectlyadjacentto
thetumour,withoutnormalbrainbetweenthecraniotomy
andthetumour.DeAlmeidaetal.in2015,showedastudy
thatwhencomparedtothetraditionalbifrontalcraniotomy,
Figure6 Tridimensionalreconstructionofpostoperativehigh definitionheadCTwithalargebonedefectfromtheplanum sphenoidaletothecristagalli.
the endoscopic endonasal approach had significantly less
oedemaintheadjacentbrain,showingashyperintensityon
theFLAIRsequenceofthepostoperativeMRI.Sucha
differ-encewasattributedtothebrainretractionnecessaryinthe
traditionalbifrontalcraniotomyapproachanditisrelatedto
post-operativeischaemiaandhaemorrhagesandlongterm
cognitivechanges.21,22
The main concern withthe endonasal approachis the
highrateofpostoperativeCSFleak.Beforetheuseof
vas-cularizedflapstheserateswerebetween30%and40%.3,18,23
VanGompeletal.publishedameta-analysisshowingaCSF
leakforthisapproachof26%24;deAlmeidaandcolleagues
showed an incidenceof 30%21; Prevedello etal., in 2015,
27.8%22 andthePittsburghSkullBaseTeam,30%.18Mostof
these studiesincluded or were basedon dataprevious to
theroutineuseofvascularizedflaps.Morerecent studies,
basedondatawithvascularizedflaps,showCSFleakratesat
16.1---20%.Asthesurgicalteamgainsmoreexperienceand
familiaritywiththeseprocedures,theCSFleakratestend
togreatlydecrease.18,19,25,26
Withthisinmind,inanteriorskullbasesurgerieswithan
extensivedefecttheuseofavascularizedflapisparamount
tocorrectandavoidCSFleaksandpostoperativemeningitis.
The nasoseptalflapis notalways available withsufficient
size to cover the defect. In this study, we present two
patientswhounderwentasuccessfulendoscopicendonasal
approach withskull base reconstruction using the double
vascularized flap technique. Such technique had already
been previously suggested,12,13,27,28 however always when
usingacraniotomyforthepericranialflap.Weheredescribe
ourtechniquewithoutneed foracraniotomy,usingonlya
small‘window’(20mm×5mm)intheanteriorwallofthe
frontal sinus(Fig.3)witha DrafIII16,29 toreachthenasal
cavityandtheanteriorfossadefect.
The double flap technique is a complementary
recon-struction for extensive defects, in which each flap
strengthenstheother’sweakpointsaswellasthemostlikely
places forCSFleaks.The nasoseptalflap hastheanterior
part of the defect, close tothe frontal sinus its weakest
area.Complementary,thepericranialflaphasitsweakest
areaintheposteriorpartofthedefectwherethe
nasosep-talflapisreinforced.Therefore,theircombineduseleaves
noinherentweakpointsandfurtherreducestheincidence
ofCSFleaks.
We also chose to use an inlay fascia lata graft for
greaterrigidityandsupporttoavoidapossiblefrontallobe
herniation.Eventhoughitisarareevent,herniationis
doc-umented in the literature30 and its main risk factors are
increasedintracranial pressure,usually relatedtoan
ele-vatedBMIwithorwithoutobstructivesleepapnea(OSA).31
Theuseofrigidautologous(e.g.boneorcartilage)or
het-erologous(e.g.titaniummesh)arecontroversialandshould
beregardedasalastresortduetoitshigherratesof
infec-tionandextrusionofsuchmaterialsleadingtoevengreater
complications.30
Anotherbenefitofthedoubleflapisfasterhealinggiven
the increasedblood supply to the area,allowing
comple-mentarytherapies(e.g.radiotherapy)tobestartedsooner.
Thepatientsherepresentedhadnoindicationforit,butin
malignanttumourswheretimebetweensurgeryand
radio-therapymaybeanimportantprognosticfactoritisanother
advantageofthistechnique.12
Harvestingthepericranialflaprequiresabicoronal
inci-sion. However, since there is no muscle or bone flap
removed or even manipulated, healing tends to be
with-outcomplications, witha verygood aestheticresult.The
bone window opened in the frontal sinus is covered with
theskin and filledwiththeflap,leavingnoimpression or
external mark.There is descriptionof an endoscopic
har-vestingofthepericranialflapusingthreesmallincisions(at
theglabellaandinthescalponeithersides)10 howeverit
isatime-consumingtechniquewithlittleadvantagetothe
aestheticfinalresult.
There aresome important restrictions tochoosing this
approach, suchasan unfamiliarityof manyneurosurgeons
with it, lateral extension of the tumour and a preserved
olfaction.
This neurosurgeon unfamiliarity can be overcome by
traininginexperimentalconditionsinalab,trainingcourses,
accompanying a more experienced neurosurgeon in this
kind of procedure and starting with smaller and simpler
endonasal procedures.Even then,long learningcurve can
belong.
Thelateralextensioncanbehelpedbytheuseofangled
scopes and adequate instruments. If even under optimal
conditionsagrosstotalresectioncannotbeachievedwithan
endonasalapproach,asecondstageapproachcanbeused
thisbeingatraditionalcraniotomywhichwillfindthebrain
more relaxed, improved surgical corridor, smaller tumour
andwithnoneedorlittleneedforretraction.
A preserved olfactiondoes notpreclude theendonasal
transcribriformapproach, butthe patientshouldbemade
awarethatthechancesofpreservingolfactionareminimal
andtheimpactitmayhave(e.g.forsommeliers,food
crit-ics and relatedprofessions). It is important toremember
that the traditional technique also has a risk for
post-operative anosmia, although smaller than the endonasal
technique.18,19,21
Conclusion
Theendoscopicendonasalapproachestotheanteriorskull
basehave manyadvantages overtraditionalcraniotomies;
however the elevated rates of CSF leaks and associated
complications were always a major concern. The use of
vascularizedflapshasgreatlyreducedthesecomplications
andwe present thistechnique, that we considerit tobe
a safe and effective option, with the endoscopic double
flap(pericranialand nasoseptal),reinforcedwitha fascia
latafreegraftinlay,asanalternativetofurtherreducethe
complicationsofthisapproach.
Conflicts
of
interest
Theauthorsdeclarenoconflictsofinterest.
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