www.bjorl.org
Brazilian
Journal
of
OTORHINOLARYNGOLOGY
ORIGINAL
ARTICLE
Surgical
treatment
of
choanal
atresia
with
transnasal
endoscopic
approach
with
stentless
single
side-hinged
flap
technique:
5
year
retrospective
analysis
夽
Carmelo
Saraniti,
Manuela
Santangelo,
Pietro
Salvago
∗UniversitàdegliStudidiPalermo,DipartimentodiBiomedicinaSperimentaleeNeuroscienzeCliniche(BioNeC), SezionediOtorinolaringoiatria,Palermo,Italy
Received22December2015;accepted2March2016 Availableonline22April2016
KEYWORDS
Choanalatresia; Endoscopicnasal surgery;
Re-stenosis
Abstract
Introduction:Choanalatresiaisararecongenitalmalformationofthenasalcavity character-izedby thecompleteobliterationoftheposterior choanae.In67%ofcaseschoanalatresia isunilateral,affectingmainly(71%)therightnasalcavity.Incontrasttotheunilateralform, bilateralchoanalatresiaisalife-threateningconditionoftenassociatedwithrespiratory dis-tresswithfeedingandintermittentcyanosisexacerbatedbycrying.Surgicaltreatmentremains theonlytherapeuticoption.
Objective: Toreportourexperienceintheuseofatransnasalendoscopicapproachwith stent-lesssingleside-hingedflaptechniqueforthesurgicalmanagementofchoanalatresia.
Methods:A5yearretrospectiveanalysisofsurgicaloutcomesof18patientstreatedforchoanal atresiawithatransnasaltechniqueemployingasingleside-hingedflapwithoutstentplacement. AllsubjectswereassessedpreoperativelywithanasalendoscopyandaMaxillofacialcomputed tomographyscan.
Results:Tenmalesandeightfemaleswithameanageatthetimeofsurgeryof20.05±11.32 years,underwent surgeryfor choanal atresia.Fifteen subjects(83.33%)hadabony while3 (26.77%)amixedbony-membranousatreticplate.Twoandsixteencasessufferedfrombilateral andunilateralchoanalatresiarespectively.Nointra-and/orearlypostoperativecomplications wereobserved.Between2and3monthsaftersurgerytwocases(11.11%)ofpartialrestenosis werefound.Onlyoneofthesepresentedarelapseofthenasalobstructionandwassubsequently successfullyrepairedwithasecondendoscopicprocedure.
夽 Pleasecitethisarticleas:SaranitiC,SantangeloM,SalvagoP.Surgicaltreatmentofchoanalatresiawithtransnasalendoscopicapproach withstentlesssingleside-hingedflaptechnique:5yearretrospectiveanalysis.BrazJOtorhinolaryngol.2017;83:183---9.
∗Correspondingauthor.
E-mail:[email protected](P.Salvago).
PeerReviewundertheresponsibilityofAssociac¸ãoBrasileiradeOtorrinolaringologiaeCirurgiaCervico-Facial.
http://dx.doi.org/10.1016/j.bjorl.2016.03.009
Conclusion:The surgical technique described follows the basic requirements of corrective surgeryandallowsgoodvisualization,evaluationandtreatmentoftheatreticplateandthe posteriorthirdoftheseptum,inordertocreatethenewchoanalopening.Webelievethatthe useofastentisnotnecessary,asrecommendedincaseofothersurgicaltechniquesinvolving theuseofmoremucosalflaps.
© 2017 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
Atresiadecoana; Cirurgianasal endoscópica; Restenose
Tratamentocirúrgicodeatresiadecoanacomabordagemendoscópicatransnasal comtécnicaderetalhoúnicoearticulac¸ãolateralsemcolocac¸ãodestent:análise retrospectivade5anos
Resumo
Introduc¸ão:Aatresiadecoanaséumamalformac¸ãocongênitararadacavidadenasal carac-terizadapelaobliterac¸ãocompletadacoanaposterior.Nos67%doscasosaatresiacoanalé unilateral,acometendoprincipalmente(71%)acavidadenasaldireita.Diferentementedaforma unilateral,aatresiacoanalbilateraléumacondic¸ãocomriscodevida,frequentemente asso-ciadaaangústiarespiratóriacomalimentac¸ãoecianoseintermitenteexacerbadapelochoro. Otratamentocirúrgicopermanececomoaúnicaopc¸ãoterapêutica.
Objetivo:Relataranossaexperiêncianousodeumaabordagemendoscópicatransnasalcoma técnicaderetalhoarticuladodeumladosósemcolocac¸ãodestentparaotratamentocirúrgico daatresiacoanal.
Método: Análiseretrospectivade5anosdosdesfechoscirúrgicosde18pacientestratadospara atresiacoanalcomumatécnicatransnasalcomumúnicoretalhodearticulac¸ãolateral,sem colocac¸ãodestent.Todososindivíduosforamavaliadosnopré-operatóriocomumaendoscopia nasaleumexamedetomografiacomputadorizadamaxilofacial.
Resultados: Dez homens e oito mulheres com idade média no momento da cirurgia de 20,05±11,32 anos foram submetidos a cirurgia para atresia de coanas. Quinze pacientes (83,33%) apresentaram placa atrésica óssea, enquanto 3 (26,77%) apresentaram uma placa atrésicaósseo-membranosamista.Doisedezesseiscasossofriamdeatresiacoanal bilateral eunilateral,respectivamente.Nãoforamobservadascomplicac¸õesintrae/oupós-operatórias precoces.Entre2e3mesesapósacirurgia doiscasos(11,11%) derestenoseparcialforam encontrados. Apenasum delesapresentou umarecidiva daobstruc¸ãonasal e,portanto,foi reparadocomsucessocomumsegundoprocedimentoendoscópico.
Conclusão:Atécnicacirúrgicadescritasegueosrequisitosbásicosdecirurgiacorretivae possi-bilitaboavisualizac¸ão,avaliac¸ãoetratamentodaplacaatrésicaedoterc¸oposteriordosepto,a fimdecriaranovaaberturacoanal.Pensamosqueautilizac¸ãodeumstentnãoénecessária,tal comorecomendadonocasodeoutrastécnicascirúrgicasqueenvolvemousodemaisretalhos demucosas.
© 2017 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
Withafrequencyofonein5000---7000births,choanalatresia (CA)isa rarecongenitalmalformationof thenasalcavity characterizedbythecompleteobliterationoftheposterior choanae.1CAwasreportedfirstbyRoedererin1755while
examininganewbornwithtotalobstructionoftheposterior nasalchoanaandlaterdescribedbyOttoin1829duringan autopsy2,3;thefirstsurgicalapproachtoCAwasproposedin
1851byEmmert,whofirstsuccessfullycorrected CAusing transnasalsurgeryofthepalate.4
Both genders are affected, with a male to female ratio of 1:2. In 70% of cases the malformation is mixed
bony-membranous type, while in theremaining it is pure bonytype.5In the67%of casesCAis unilateral, affecting
mainly(71%)the rightnasalcavity. Incontrasttothe uni-lateralform,whichcanbeunrecognizedforyears,bilateral CAisalife-threateningconditionoftenassociatedwith dra-maticclinicalfeatureslikerespiratorydistresswithfeeding andintermittentcyanosisexacerbatedbycrying.
syndromes6; in such cases, because of the severe
respi-ratory symptoms,a combined CA surgical treatment with tracheostomyis often necessary toguaranteesafe airway management.
Hengerer and Strome attributed the CA embryological foundations to four factors: (1) Persistence of the buc-copharyngealmembrane fromtheforegut;(2)Persistence ofHochstetter’sbucconasal membrane;(3)Abnormal per-sistence or location of mesoderm in the choanal region; (4) Misdirection of the mesodermal flow, withan altered migrationofneuralcrestcellswhichfailtoreachtheir pre-ordainedpositioninthefacialprocesses.7
OnceCAhasbeendiagnosed,surgicaltreatmentremains the only therapeutic option. Several surgical approaches were previously reported, like transnasal, transantral, transpalatineandtranseptal.
Theaimofthispaperwastoreportourexperienceinthe surgical management of18 cases of CAusing a minimally invasivetransnasalendoscopicapproachwithstentless sin-gleside-hingedflaptechnique.
Methods
We evaluated the surgical results of 18 patients (ranging from8---57yearsofage)treatedforCAbetween 2001and 2005. Approval for this retrospective study was obtained fromthelocalethicalcommittee(approvalnumberV5605). FourteenpatientswereaffectedbyunilateralandbonyCA (Fig.1),onebyunilateralandmixed(Fig.2),oneby bilat-eral and bony, and two by bilateral and mixed. Bilateral CAforms were reinterventionsin patients whohad previ-ously undergone surgery at other departments. No cases ofgeneticsyndromeswerefound.Clinicalandradiological assessmentswereperformed preoperativelyinallpatients andcomprisedanasalendoscopyandaMaxillofacialCTscan to determine the extent of the atretic plate and to rule outanyothercraniofacialanomaly.Thesurgicalprocedure, undergeneralanesthesia,wasperformedby0◦and30◦4or 2.7mmtelescopes(KarlStorz)dependingontheageofthe patient.
Figure1 AxialCTscan,monolateralleftbonychoanal atre-sia.
Figure2 AxialCTscan,monolateralleftmixedchoanal atre-sia.
Weusedatransnasaltechniquewithasingleside-hinged flapwithout stentplacement.Itis basedonthefollowing steps:
1. After the oral intubation, the nose is topically decongested.Ifnasal septumdeviation exists,a hemi-transfixion incisioniscreated onthe rightof thenasal septum,withrightsubperichondralandbilateral subpe-riosteal dissectionandcorrection ofseptaldeformities performed.
2. Verticalincisionofthenasalmucosawithasickleknifeat thejunctionoftheatreticplatewithvomeriscreated;by addingtwohorizontalincisions,onehigheratthechoanal archandanotherlowerattheedgebetweentheatretic plateandthefloorofthenasalcavity(Figs.3and4A), a side-hinged flap is elevated and laterally displaced
mt
it
S
Figure4 Mainsurgicalstepsofendoscopicchoanoplastytechniquefromrightnasalcavity:I.T.,inferiorturbinate;M.T.,middle turbinate;S,septum,A.P.,atreticplate;F,nasalfloor.
(Fig.4BandFig.5A).Thisstepcanbecompletedbythe upwarddislocationoftheinferiorturbinateinorderto improvetheexposureofthesurgicalfield.
3. Perforation of the CA is performed at the level of its inferomedialportionandsubsequentcomplete removal of the atretic plate together with the mucosa of the
nasopharyngealaspectwithbonebitingforcepsor micro-drilliscarriedout(Fig.4C).
4. Resectionofposteriorthirdofthebonyseptum(vomer, ethmoidal lamina) with back-biting forceps and drill ensues,withbilateralverticalsectionwithangledknife ormicro-scissorsof theseptalmucosasothat onlythe
Table1 Clinicalcharacteristicsofpatients.
Cases Gender Age Laterality Type Nasalpacking Restenosis
1 M 27years Right Bony 4days No
2 M 25years Left Bony 5days Yes
3 F 10years Right Bony 4days No
4 M 20years Left Mixed 3days Yes
5 F 9years Left Bony 3days No
6 F 11years Left Bony 3days No
7 M 13years Left Bony 4days No
8 F 12years Right Bony 4days No
9 M 8years Bilateral Bony 7days No
10 F 57years Bilateral Mixed 7days No
11 M 17years Right Bony 4days No
12 M 27years Left Bony 5days No
13 F 19years Left Bony 4days No
14 M 21years Left Mixed 4days No
15 M 15years Right Bony 5days No
16 M 23years Left Bony 3days No
17 F 29years Right Bony 4days No
18 F 18years Right Bony 5days No
posterior edge of the bony septum is resurfaced by approximation of the two mucoperiosteal septal sides (Fig.4Dand 5B). Finally,positioningof Merocel® nasal packingfromaminimumof 3toamaximum of 7days (mean4.4)isfavored.Stentswerenotplacedinanycase. Notopicalmitomycinorcorticosteroidswereapplied.
IncaseofbilateralCA,thesameprocedureisperformed onthe contralateralside (Fig.5C). Duringthe immediate postoperative period an antibiotic therapy was adminis-teredand,afternasalpackingremoval,anasalsalinespray therapyatleasttwiceadayfor severalweekswas recom-mended.Patientsunderwentaregularendoscopicfollow-up to wash awasy crusts and secretions and verify choanal patency.
Results
Table 1 shows clinical characteristics of the eighteen patientsincludedinourstudy.Tenmalesandeightfemales (male/femaleratio=1:1.25),withameanageatthetime of surgery of 20.05±11.32 years (median=18.5 years), underwent CA treatment. Fifteen subjects (83.33%) had a bony atretic plate while three (26.77%) a mixed bony-membranousatreticplate.Two andsixteen casessuffered frombilateralandunilateral(9left-and7right-sided)CA respectively.TwocasesofbilateralCAwereobserved,an8 year-oldchildanda 57year-oldwoman,bothaffectedby restenosisafterinitialsurgicaltreatmentatbirthwith sim-pleperforationandstentplacement.Nopatientssuffered fromGastroesophagealRefluxDisease(GERD).
All surgical procedureswere completed within140min (surgicaltimerange=60---140min;mean=87min).A septo-plasty witha maxilla-premaxillaapproach wasperformed in7patients(38.88%) whowereaffectedby nasalseptum deviation.CAtreatmentwasnotassociatedwith adenoidec-tomy in the 8and 9 year-oldchildren (Patients 9 and 5).
Hospitalization time ranged from 3 to 5 days (mean=3.8 days). The mean time for nasal packing removal was 4.33±1.18days (median=4 days).No intra-and/or early postoperative complications such as epistaxis, infection, erosionofthenaresorintranasalsynechiaeoccurred.
All patients underwent postoperative follow-up with nasalendoscopy.Overallfollow-upperiodrangedfrom1to 10years(mean7.4years).Between2 and3monthsafter surgicaltreatmenttwocases(11.11%)ofpartialrestenosis (Patients2and4)onthefloorofthenasalcavitywerefound. Onlyone(5.55%)ofthese(Patient4)presentedarelapseof thenasalobstruction(Fig.6)andwasthereforesuccessfully
it
S
nf
repairedwithasecondendoscopicprocedurewithout posi-tioningofastent.The16remainingpatientswhounderwent surgeryhadsatisfactoryfunctionalpatencyofthechoanae, withoutrespiratorydiscomfortor secretionsinthe follow-up,anddefinitechoanalpatencywasconfirmedwithnasal endoscopy.
Discussion
Presentlythereisnouniqueorstandardizedtechniqueinthe managementofCA.Surgicalcorrectioniscloselyrelatedto patientageandanatomicalcharacteristicsoftheCAitself: mono-orbilateral,partialorcomplete,membranous,bony ormixed.
Becauseofneonatesareobligatenasalbreathers, com-plete bilateral CA is a medical urgency which demands urgenttemporaryoral airwaymaintenanceuntiladequate or clinically patent posterior nasal choanae is surgically established,generallywithatrans-nasalapproach.8Onthe
contrary,patientswithunilateralorincompleteCAareoften diagnosed and treated later in life, when patients seek medicalattentionbecauseoflong-standingunilateralnasal obstruction,anosmiaandrhinorrhea.
Fourmain CA surgical approaches aredescribed inthe medicalliterature:trans-palatal,trans-antral,trans-septal, and trans-nasal. The trans-palatal approachoffers a very widefieldforoperation,makingcorrectivemaneuvers eas-ier,butismoreinvasiveandsusceptibletocomplicationslike bleeding,fistulas,infectionsandgrowthdefectsofthejaw andthepalate bone.9,10 The trans-antral approachisonly
ofhistoricalinterestandalsopermitsanadequateexposure ofthesurgicalfield,allowingaquickcheckforany bleed-ingandlessrisk of damagingthe sphenopalatinearteries, veinsandnerves,butcan significantlyincreasetheriskof deformitiesof growing structuressuchasthe maxillaand upperteeth.11 Thetrans-septalapproachisrecommended
incaseofunilateralCAandinpatientsolderthan8years;it permitsbettercorrectionofanydeviationsoftheseptum, resectionoftheposteriorpartofthevomerandpreservation ofmucosalflapsforcoverageofthebleedingarea.12
Thetrans-nasalapproachiscurrentlythemostfrequently used,duetothe modernrefinementsof endoscopic tech-niques (it does not affect the growth of the mandibular arch,therearenomalocclusionsorcosmeticalterationsto theface),especially innewborns withbilateral CAwhere a puncture of the atretic plate via the nostrilswith sub-sequent use of Fearon dilators and stent placement are generallyperformed.13Inyoungpatients,whentheethmoid
sinuseshave reached asatisfactory levelof development, andinadults,itispossibletomakeincisionsofthemucosa oftheatreticplate,asreportedbydifferentauthors.The mostcommontechniquesfor incisionare:doublemucosal anteriorandposterior low-hinged flap,12 side-hinged
dou-bleflap,14,15 upper hinged flap,16 four flaps with cruciate
incisions,11,17,18doublenasalandseptalflap,19andmultiple
flapssecuredwithfibringlue,20---22 soastoobtainmucosal
flaps for the re-covering of the raw areas at the level of themediallaminaofthepterygoidprocessandthe poste-riorpartoftheseptum.Otherauthorsinsteaddidnotflap techniques, such asEl-Ahl etal. who performed a stent-lesstransnasalendoscopicapproachtotreatbilateralCAin
7neonates(rangingfrom4to15daysoflife)without evi-denceofrestenosis.23Additionally,toenlargethechoanato
themaximumpossiblesize,Liktoretal.,suggested,incases inwhichtheatreticplateissuitablythinandthe develop-mentalstatusofthesphenoidsinusandtheethmoidcellsis adequate,openingtogetherthesphenoidsinusandthe pos-teriorethmoidcells,resectingalsotheposteriorpoleofthe middleturbinate;however,thismodifiedtechniquemaybe consideredtomanageonlyselectedcaseslikepostoperative stenosisandunilateralCAinpatientsover7yearsofage.24
The topical application of mitomycin C, an aminogly-coside which inhibit fibroblastgrowth and migration,was also suggested to reduce risk of restenosis after surgery and improve the healing process; however its use is still controversial.25---30Forexample,Bozkurtetal.,studying12
patientswhounderwentsurgeryforchoanalatresiawithand withouttheuseofmitomycinC,reportednocaseof resteno-sisinthefirstgroupandformationofgranulationtissuein the42.9%of thesecondgroup.30 On thecontrary,
Uzome-funaetal.didnotfindanysignificantdifferencebetween patientswhoweretreatedatinitialsurgerywithtopical mit-omycinCandpatientswhohadnomitomycinCapplication (53%vs.60%).31
SuccessfulCA surgical outcomesare influenced by the presence/absence of factors like nasopharyngeal reflux, GERD, age <10 days(associated withlimited visualization in nosesofneonates andlimited resectionofthevomer), bilateral CAwithpurely bonyatreticplate andassociated malformations.9,27Noneoftheseriskfactorswasidentified
inourpatientswiththeexceptionofbilateralCA,foundin twosubjects(11.11%)whoexperiencednorestenosisafter ourtreatment.
Ourstudy,withonlytwocases(11.11%)ofpartial resteno-sis, showed good surgical outcomes without the use of a postoperativestenting.Similarrateofrestenosis(14%)were reportedbyIbrahimetal.whoperformedalsoanendoscopic stentless choanoplasty with a single side mucoperiosteal flaptotreat21CAchildren.32 Itisdifficulttomakeareal
comparisonbecauseof the differentdemographic charac-teristicsofthesamplestudied,thehighnumberofbilateral CAincluded(11/21)andtheshorterfollow-upperiod.
Itisclearthatastentlesstechniqueavoidsthepotential stent-related complications (such asdiscomfort,localized infectionandulceration,circumferentialscarorgranulation tissueformation) but needs tobeassociatedwith aclose post-operativefollow-up.33 However,asreportedin a
sys-tematicreviewbyCedinetal.,withaabsoluteriskfornot needingareoperation(0.81),thecomparisonbetween sur-gerieswithandwithoutstentdidnotproveanysignificant evidenceinfavorofaspecifictechnique.34
Conclusion
We suggest the use of this transnasal endoscopic surgery becauseit followsthe basic requirementsof a minimally-invasive corrective approach: the creation of a widely patentposteriornasalchoanasufficientfornormalbilateral nasalbreathing,absenceofsecretionaccumulation, mini-mizationofendonasalscartissueformationandprevention of abnormalcraniofacialgrowthin children whohave not reachedtheirfullgrowthyet.
Conflicts
of
interest
Theauthorsdeclarenoconflictsofinterest.
References
1.RamsdenJD,CampisiP,ForteV.Choanalatresiaandchoanal stenosis.OtolaryngolClinNorthAm.2009;42:339---52. 2.FlakeCG,FergusonCF.CongenitalChoanalatresiaininfantsand
children.AnnOtolRhinolLaryngol.1964;73:458---73.
3.OttoA,LehrbachD.PathologischenAnatomicdesMenschenund derThiere,vol.1.Berlin:Recker;1830.p.181---3.
4.EmmertC.StenochorieundAtresiederChoannen,Lehrbachder SpeciellenChirurgie,vol.2.Stuttgart:Dann;1854.p.535---8. 5.Brown OE, Pownell P, Manning SC. Choanal atresia: a new
anatomicclassificationandclinicalmanagementapplications. Laryngoscope.1996;106:97---101.
6.DuncanNO,MillerRH,CatlinFI.Choanalatresiaandassociated anomalies:theCHARGEassociation.IntJPediatr Otorhinolaryn-gol.1988;15:129---35.
7.HengererAS,Strome M.ChoanalAtresia:anewembryologic theoryanditsinfluenceonsurgicalmanagement.Laryngoscope. 1982;92:913---21.
8.SaettiR,EmanuelliE,CutroneC,BarionU,RiminiA,GiustiF, etal.Thetreatmentofchoanalatresia.ActaOtorhinolaryngol Ital.1998;18:307---12.
9.KwongKM.Currentupdatesonchoanalatresia.FrontPediatr. 2015;3:1---6.
10.daFontouraReyBergonseG,CarneiroAF,VassolerTM.Choanal atresia:analysisof16cases---theexperienceofHRAC-USPfrom 2000to2004.BrazJOtorhinolaryngol.2005;71:730---3. 11.KamelR.Transnasalendoscopicapproachincongenitalchoanal
atresia.Laryngoscope.1994;104:642---6.
12.HallWJ,WatanabeT,KenanPD,BaylinG.Trans-septalrepairof unilateralchoanalatresia.ArchOtolaryngol.1982;108:659---61. 13.GujrathiCS,DanielSJ,JamesAL,ForteV.Managementof bilat-eralchoanalatresiaintheneonate:aninstitutionalreview.Int JPediatrOtorhinolaryngol.2004;68:399---407.
14.McIntosh WA. Trans-septal approach to unilateral posterior choanalatresia.JLaryngolOtol.1986;100:1133---7.
15.CedinAC,RochaJF,DeppermannMB,MoraesManzanoPA,Murao M,ShimutaAS.Transnasalendoscopicsurgeryofchoanalatresia withoutuseofstents.Laryngoscope.2002;112:750---2.
16.El-Guindy A, El-Sherief S, Hagrass M, Gamea A. Endoscopic endonasalsurgeryofposteriorchoanalatresia.JLaryngolOtol. 1992;106:528---9.
17.Stankiewicz JA. The endoscopic repair of choanal atresia. OtolaryngolHeadNeckSurg.1990;103:931---7.
18.CumberworthVL,DjazaeriB,MackayIS.Endoscopic fenestra-tionofchoanalatresia.JLaryngolOtol.1995;109:31---5. 19.PasquiniE,SciarrettaV,SaggeseD,CantaroniC,MacrìG,Farneti
G. Endoscopictreatmentofcongenitalchoanalatresia. IntJ PediatrOtorhinolaryngol.2003;67:271---6.
20.CedinAC,FujitaR, CruzOLM.Endoscopictranseptalsurgery forchoanalatresiawithastentlessfolded-over-flaptechinique. OtolaryngolHeadNeckSurg.2006;135:693---8.
21.UriN,GreenbergE.Endoscopicrepairofchoanalatresia: prac-ticaloperativetechnique.AmJOtolaryngol.2001;22:321---3. 22.BeinfieldHH.Surgeryforbilateralbonyatresiaofthe
poste-riornaresinthenewborn.ArchOtolaryngolHeadNeckSurg. 1959;70:1---6.
23.El-AhlMA,El-AnwarMW.Stentlessendoscopictransnasalrepair ofbilateralchoanalatresiastartingwithresectionofvomer.Int JPediatrOtorhinolaryngol.2012;76:1002---6.
24.Liktor B, Csokonai LC, Gerlinger I. A new endoscopic sur-gical method for unilateral choanal atresia. Laryngoscope. 2001;111:364---6.
25.HollandBW,McGuirtWF.Surgicalmanagementofchoanal atre-sia:improvedoutcomeusingmitomycin.ArchOtolaryngolHead NeckSurg.2001;127:1375---80.
26.PrasadM,WardRF,AprilMM,BentJP,FroehlichP.Topical mito-mycinasanadjuncttochoanalatresiarepair.ArchOtolaryngol HeadNeckSurg.2002;128:398---400.
27.RombauxP,deToeufC,HamoirM,EloyP,BertrandB,Veykemans F.Transnasal repair ofunilateral choanal atresia. Rhinology. 2003;41:31---6.
28.McLeodIK,BrooksDB,MairEA.Revisionchoanalatresiarepair. IntJPediatrOtorhinolaryngol.2003;67:517---24.
29.Teissier N, Kaguelidou F,Couloigner V,Franc¸ois M, Van Den AbbeeleT.Predictivefactorsforsuccessaftertransnasal endo-scopictreatmentofchoanalatresia.ArchOtolyngolHeadNeck Surg.2008;134:57---61.
30.BozkurtMK,KelesB,AzimovA,OzturkK,ArbagH.Theuseof adjunctivetopicalmitomycininendoscopiccongenitalchoanal atresiarepair.IntJPediatrOtorhinolaryngol.2010;4:733---6. 31.UzomefunaV,GlynnF,Al-OmariB,HoneS,RussellJ.Transnasal
endoscopic repair of choanal atresia in a tertiary care cen-tre: a review of outcomes. Int J Pediatr Otorhinolaryngol. 2012;76:613---7.
32.Ibrahim AA, Magdy EA,Hassab MH.Endoscopic choanoplasty without stenting for congenital choanal atresia repair. IntJ PediatrOtorhinolaryngol.2010;74:144---50.
33.Schoem SR.Transnasal endoscopic repair ofchoanal atresia: whystent?OtolaryngolHeadNeckSurg.2004;131:362---6. 34.Cedin AC, Atallah AN, Andriolo RB, Cruz OL, Pignatari SN.
