ReceivedJuly252001RevisedOctober112001AcceptedOctober17 EMBRYOLOGYANDASSOCIATEDANOMALIESTheexactpathogenesisoftrachealagenesisisunknownSeveraltheorieshavebeenadvocatedallofwhichsuggestavulnera ID: 446878
Download Pdf The PPT/PDF document "TrachealAgenesisCMichaelHaben,,JamieMRap..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
TrachealAgenesisCMichaelHaben,,JamieMRappaport,FRCS),KevinDClarke,FRCSTrachealagenesisisoneoftherarestofcongenitalmal-formationsoftheairway.Thecaseofanewborninfantwhopresentedwithimmediaterespiratorydistressisde-scribed.Surgicalandpathologicalexaminationcon-firmedadiagnosisofcompleteagenesisofthetrachea, ReceivedJuly25,2001;RevisedOctober11,2001;AcceptedOctober17, EMBRYOLOGYANDASSOCIATEDANOMALIESTheexactpathogenesisoftrachealagenesisisunknown.Severaltheorieshavebeenadvocated,allofwhichsug-gestavulnerablefocusduringtheearlyembryologicdif-ferentiationoftherespiratorytract.Therespiratorysys-temnormallyformsasamidline,ventraldiverticulum,whichitselfarisesfromtheproximalforegutat26daysgestation.Within10days,thelaryngotrachealgroovesappearlaterallyanddeepentoformthetracheoesopha-gealseptum.Ithaslongbeentaughtthatthisprocessisthoughttoproceedinacephaladdirectiontoeventuallyseparatetherespiratoryprimordiumfromtheesopha-Recentexperimentshavesuggestedthatprepro-grammedcelldeathintheareadesignatedasthetracheo-esophagealseptumisresponsibleforseparation,ratherthancellularproliferation.Meanwhile,therespiratorydiverticulumbifurcatestoformthelungbudsandacartilaginousframeworkformsfromsurroundingmes-enchymaltissue.Fromanimalexperiments,ithasbeenshownthatlungdevelopmentdependsontwomainfactors.First,theremustbeasufficientquantityoffluidinthelungs,andsecond,thefetalbreathingmovementsmustbeadequate.Inthecasepresentedhere,theremusthavebeensufficientleakageoffluidthroughthebronchoesophagealfistuladuringfetallifetopreventhypoplasiaofthebabyslungs.Incontrast,theproximallarynxdevelopsfromthepharyngealfloorandbranchialarches(primarilythearch).Thecricoiddevelopsfromtheproximaltrachea,whichmayexplaintheassociationofcricoidanomalieswithtrachealagenesis.Holingerandcol-studiedtwocasesoftrachealagenesisusinghorizontalserialsections.Anellipticcricoidcartilagewasfoundinbothcases.Theysuggestedthatcongenitallaryngealanomaliesmayhavebeenpresent,butunrec-ognized,inpreviousreportsoftrachealagenesis.Asim-ilarfindingwasseeninthiscase(Fig.4).Laryngocheoesophagealclefts,completelaryngealagenesis,andwebbingofthevocalcordshavealsobeende-scribedinassociationwithtrachealagenesis.Theassociationoftrachealagenesiswithothermul-tiorgancongenitalmalformationshasbeenatopicofinterest.ThehighincidenceofassociatedanomalieshasledsomeauthorstosuggestthattrachealagenesismaybeoneofthecomponentsoftheVACTERLassociation.VACTERLincludesvertebralanomalies,analatresia,cardiacanomalies,tracheoesophagealfistulaoresopha-gealatresia,renalmalformations,andlimbdefects.Al-thoughmanyofthereportedcasesoftrachealagenesisshareanomalousfeatureswiththeVACTERLassocia-tion,Evansandcolleaguessuggestedthattrachealagenesisisnotapartoftheassociationitself.Rather,theybelievedthattrachealagenesisisonemanifestationofadifferentpatternofmalformationsthatincludestrachealagenesisorlaryngotrachealatresia,complexcongenitalcardiacanomalies,radialraydefects,andduodenalatre-sia(TACRDassociation).Morerecentlytheyreviewednearly100casesoftrachealagenesiswithmultiplecon-genitalanomalies,andstatethatthecomplexityoftheassociatedmalformationsmayrepresentincreasinglyse-veredisruptionofthefieldsencompassingthedevelop-ingrespiratorytract.Suchdistinctionsbecomeimportantinstudiesofpathogenesis,prevention,andprognosis.Categorizationfacilitatescounsellingofaffectedfamilies.Thepatient Figure1.Dissectedautopsyspecimen,posteriorview,includingtransectedbaseoftongue,larynx,esophagus,heart,lungs,andgreatvessels.Notethecompleteabsenceofatrachea.Thelarynxendsinablindpouchimmediatelybeyondthecricoidcartilage.TrachealAgenesisJAmCollSurg presentedhereexhibitedtrachealandcardiacanomalies,butlackedotherfeaturestoclearlyshareeithertheVACTERLorTACRDassociations.DIAGNOSISANDMANAGEMENTInNorthAmerica,prenatalultrasonographyisthestan-dardofcareinmanyobstetricsandgynecologicprac-tices.Ultrasonographicnormativedatahavebeencol-lectedforfetalaerodigestivetracts,andhavebeenusedforprenataldiagnosisofcertaintrachealanomalies.Postnatalclinicaldiagnosisoftrachealagenesisshouldbesuspectedincasesofantenatalpolyhydramnios,inaninfantusuallyoflessthan37weeksgestationorweigh-inglessthan2,500grams,bornwithimmediaterespira-torydistressandvigorousrespiratoryefforts,butwithminimalairexchangedetectableonauscultation.Al-thoughexceedinglyrare,ahighindexofsuspicionisrequiredtomakethediagnosispremorbidly.Thereisnoaudiblecry,andendotrachealintubationisimpossible.Ventilationistransientlyachievedonlyifatracheo-esophagealorbronchoesophagealfistulaexists,andatightly-sealedmaskisapplied.Esophagealventilationproducesgastricdistension,andaftersufficientback-pressuredevelops,airpassesretrogradethroughthebronchoesophagealfistulaandintothelungs.Somarkedabdominaldistensionwillbeapparent,andcyclesofstabilizationanddeteriorationwilloccur.Radiographicfindingsmayincludeposteriorlocationoftheendotrachealtube(esophagealintubation),andabsenceofthetrachealshadow.ContrastmaterialmaydemonstrateablindingealsacandabronchoesophagealHelicalCTscanninghasbeenusedtoconfirmthediagnosis.Trachealagenesispresentsasahierarchyofproblemsthatnecessitateimmediatemanagement.Ahighindexofsuspicionisofprimeimportance.Earlystabilizationoftheinfantsairwayismandatorywhileanadequateassessmentcanbemadeofothercongenitalanomalies.Thedecisiontoattemptsalvagereconstructivemeasuresisundertakenonlyafterthefirsttwoissueshavebeenaddressed.Inmostcasesoftrachealagenesis,anoropharyngealairwayinconjunctionwithpositivepressureventilationwillprovideagraceperiodinwhichonecandevelopastrategyfortheinterimanddefinitivemanagementof Figure2.Dissectedautopsyspecimen,anteriorview.NotetheÞstulousconnection(arrow)betweenthecommonbronchus,andthedistalesophagus. Figure3.Dissectedautopsyspecimen,posteriorview,opened(dis-talesophagustransected).NotethebronchoesophagealÞstula(ar-row),allowingtemporaryventilationoftheinfant.Thecommonbronchusisseenaswell(arrowheads).Vol.194,No.1,February2002TrachealAgenesis theairway.IntypeIanomalies,anendotrachealtubemaybethreadedontoa2.7-mmHopkinsrodtelescope,allowingintubationofthedistaltrachealstumpunderdirectvisualization.IntypeIIandIIIanomalies,esoph-agealintubationwitharelativelylargeendotrachealtubetotheleveljustabovethebronchialcommunicationwillmaintainthechildsairwaytransiently,albeittenuously.Underallcircumstances,anasogastrictubeshouldbeplacedinordertoaspiratethegastriccontentsandre-ducethelikelihoodofairwaysoilingwithgastricacid.Thenasogastrictubeisalsousefulfordecompressingairfromthestomach,whichinvariablycollectswithesoph-agealventilation.Thetwoorgansystemsthatrequirethemosturgentevaluationoncetheairwayhasbeenstabilizedarethecentralnervoussystemandthecardiovascularsystem.Majormalformations,suchasmeningomyeloceleorthetetralogyofFallot,couldprecludefurtherconsiderationoftherapeuticintervention,orradicalreconstruction.Ifnoothercongenitalanomaliesareidentified,somethoughtshouldbegiventoasurgicalrearrangementoftheanatomytogivetheinfantachancetosurvive.Diazandassociatespointoutthatthismalformationisuniversallyfatalandadviseagainstreconstructivesur-gery.Instead,theyadvocatestrictlypalliativemeasures. Figure4.Horizontalsectionthroughcricoidcartilage(hematoxylinandeosinstain,10xmagnication).Notetheellipticalshapeofthecricoidcartilage. Figure5.sclassicationoftrachealagenesis.Inallthreetypesatracheoesophagealstulaexists(arrowhead).IntypeI,ashortsegmentofdistaltracheaarisesfromtheanteriorwalloftheesophagusbeforedividingintothemainstembronchi.IntypeII,thereiscompleteagenesisofthetrachea,withastulabetweentheesophagusandcarinafromwhichthetwomainstembronchioriginate(commonest).IntypeIII,thetwomainstembronchiariseindividuallyfromtheanterioresophagealwall.TrachealAgenesisJAmCollSurg Nevertheless,itisworthreviewingselectedcasesinwhichattemptshavebeenmadeatreconstruction.In1963,FonkalsrudandcolleaguesreportedacaseofaninfantgirlbornattermwithatypeIItrachealagenesis.Theydividedthecervicalesophagusintwoplaces,theproximalendofwhichwasmadeintoanesophagostomefordrainageofpharyngealsecretions.Theintermediateesophaguswassuturedtotheskintoformapseudotracheotomy,throughwhichaventilationtubewasinsertedintothecommontracheoesophagus.Thedistalesophaguswasdividedbelowtheinsertionofthemainstembronchialsegmentsinordertoisolatethetrachealizedesophagusfromgastricsecretions.Fornu-trition,agastrostomytubewasplaced.Theinfantsur-vived6weekswiththisreconstruction,eventuallysuc-cumbingtopneumonia.Todate,thelongestsurvivinginfantbornwithtra-chealagenesis,surgicallyreconstructed,wasreportedbySohandcoworkers.TheyperformedadoublebarrelcervicalesophagostomywithdistalesophagealbandingonachildbornwithaFloydstypeItrachealagenesis.Thechildwasventilatedbythreadinganendotrachealtubethroughthedistalstoma,andwasabletosurvivefor6yearsand10monthswithoutartificialventilatorysup-port,untilsuccumbingtoacuteesophagealhemorrhage.Itisimportanttonotethatthiswasonlypossiblebecausethereexistedaviablesegmentoftrachea(FloydstypeI),withnormalbronchiandlungs.Definitivesubstitutionofalargesegmentoftheupperairway,oranentiretracheaishinderedbylackofasuitablehomologoustrachealreplacementorprostheticmaterialthatwillprovideciliatedepitheliumformucousclearanceandwithstandthenormalpressurechangesandmovementofthetracheobronchialtree.Thesechal-lengesarebeginningtobemet.Anidealgraft,iffound,mustalsoallownormalgrowthanddevelopmentofthechild.Recently,animalexperimentsusingallographsandhomographshavegivenhopethattrachealtrans-plantationinhumansmayonedaybeclinicallyfeasi-Theuseofcryopreserved,irradiatedtrachealho-mographsinhumanbeingsbyNakanishiandandKunachakandassociates,hasalsoap-pearedinrecentliterature.Itshouldbenoted,however,thatsurvivingsurgicaltransplantationoftheentiretra-cheahasnotbeenaccomplished,eveninananimalmodel.Freesegmentaltrachealautographsarebeingusedsuccessfully.Thereisalimit,however,totheex-tentofthetracheathatmaybereplaced.Becharaandcoworkersperformedtotaltrachealreconstructionina3-month-oldinfantwithtrachealstenosisusinghomol-ogousleftmainstembronchus(theinfantdied48hoursExperimentaltrachealreconstructionusingavarietyofmaterialshavebeenattemptedunsuccessfully,includ-ingtheuseofsilconeelastomerandDacron(Borrieand;Nevilleandassociates),Marlexmesh(Beallandcoworkers),urinarybladderwall(Rushand;Marshakandcolleagues),andpericardium(MorghissiMostauthorswhoattemptreconstructiontendtousetheesophagusbecauseaconduittothelungsisalreadypresentthroughthebronchoesophagealfistula,asFonkalsrudandcolleaguesshowed.Ortheymayat-temptathoracictracheotomy,asHongandcolleaguesExtracorporealmembraneoxygenation(ECMO),aformofcardiopulmonarylifesupport,maybeusedtem-porarilyintheacutesettingasanalternativetoventila-tion.Thisprovidesthesurgicalteamprecioustimetoplanandexecuteareconstruction.Aninfantcanbesus-tainedonECMOforseveraldays,ifnecessary.Unfor-tunatelythesefacilitiesaregenerallylimitedtolarge,urban,tertiarycarecenters.ThevalueofECMOduringthesurgicalcorrectionoftrachealanomalieshasbeendescribed,includingitsuseduringreconstructionoflongsegmentcongenitaltrachealstenosis.Inconclusion,trachealagenesisisfortunatelyaveryrareanomaly,withlessthan100casesreportedintheliterature.Promptdiagnosisandestablishmentofventi-lationismandatory.TheroleforECMOinthesepa-tientsisstilltobedetermined.Definitiveairwaystabili-zationisoftenimpossiblebecausereconstructivetechnologyandmaterialsareinsufficienttodate.Atpresent,thisanomalyisstillconsideredtobeincompat-iblewithlife. Acknowledgment:TheauthorswishtothankLindsayPereiraforprovidingtheillustrationforFigure5.PayneWA.Congenitalabsenceofthetrachea.BrooklynMedi-calJournal1900;14:568.vanVeenedaalMB,LiemKD,MarresHA.Congenitalabsenceofthetrachea.EurJPediatr2000;159:8Vol.194,No.1,February2002TrachealAgenesis HolingerPH,JohnstonKC,ParchetVN.Congenitalmalforma-tionsofthetrachea,bronchiandlung.AnnOtolRhinolLaryn-gol1952;61:1159WeilRJ.Pathologicalquizcase1.TrachealAgenesis(FloydTypeII).ArchOtolaryngolHeadNeckSurg1991;117:804FloydJ,CampbellDC,DominyDE.Agenesisofthetrachea.AmRevRespirDis1962;86:557KoltaiPJ,QuineyR.TrachealAgenesis.AnnOtolRhinolLar-yngol1992;101:560BremerJL.Trachea,bronchi,andlungs.In:Congenitalanom-aliesoftheviscera:Theirembryologicalbasis.Cambridge,MA:HarvardUniversityPress;1957:27MooreKL.Therespiratorysystem.In:Thedevelopinghuman,clinicalorientedembryology,3rdedition.Philadelphia,PA:WBSaundersCompany;1982:217.QiBQ,BeasleySW.Preliminaryevidencethatcelldeathmaycontributetoseparationofthetracheafromtheprimitivefo-regutintheratembryo.JPediatrSurg1998;33:1660ScurryJP,AdamsonTM,CussenLJ.Fetallunggrowthinlaryn-gealatresiaandtrachealagenesis.AustPaediatrJ1989;25:BradenkampJK,MaceriDR,CrockettDM.Trachealagenesis:theimportanceofanendoscopicdiagnosis.OtolaryngolHeadNeckSurg1989;101:688HolingerLD,VolkMS,TuckerGFJr.Congenitallaryngealanomaliesassociatedwithtrachealagenesis.AnnOtolRhinolLaryngol1987;96:505EvansJA,RegginJ,GreenbergC.Trachealagenesisandassoci-atedmalformations:Acomparisonwithtracheoesophagealfis-tulaandtheVACTERLassociation.AmJMedGenet1985;21:EvansJA,GreenbergCR,ErdileL.Trachealagenesisrevisited:analysisofassociatedanomaliesAmJMedGenet1999;82:KalacheKD,FranzM,ChaouiR,BollmannR.Ultrasoundmeasurementsofthediameterofthefetaltrachea,larynxandpharynxthroughoutgestationapplicabilitytoprenataldiagnosisofobstructiveanomaliesoftheupperrespiratory-digestivetract.PrenatDiagn1999;19:211ScottJN,TrevenenCL,WisemanDA,ElliottPD.Trachealatresia:ultrasonographicandpathologiccorrelation.JUltra-soundMed1999;18:375KassanosD,ChristodoulouCN,AgapitosE,etal.Prenatalul-trasonographicdetectionofthetrachealatresiasequence.Ultra-soundObstetrGynecol1997;10:133DeJoseMariaB,DrudisR,MonclusE,etal.Managementoftrachealagenesis.PaediatrAnaesth2000;10:441HongSW,BaranGM,SchnauferL,StoolSE.Trachealagenesiswithbronchoesophagealfistula.Laryngoscope.1973;83:250PumbergerW,MetzV,BirnbacherR,HormannM.Trachealagenesis:evaluationbyhelicalcomputedtomography.PediatrRadiol2000;30:200AltmanRP,RandolphJG,ShearinRB.Trachealagenesis:Recognitionandmanagement.JPediatrSurg1972;7:112BuchinoJJ,MeagherDP,CoxJA.Trachealagenesis:Aclinicalapproach.JPediatrSurg1982;17:132DiazEM,AdamsJM,HawkinsHK,SmithRJH.Trachealagen-esis.Acasereportandliteraturereview.ArchOtolaryngolHeadNeckSurg1989;115:741FonkalsrudEW,MarteleRR,MaloneyJV.Surgicaltreatmentoftrachealagenesis.JThoracCardiovascSurg1963;45:520SohH,KawahawaH,ImuraK,etal.Trachealagenesisinachildwhosurvivedfor6years.JPediatrSurg1999;34:1541JacobsJP,QuintessenzaJA,AndrewsT,etal.Trachealallograftreconstruction:thetotalNorthAmericanandworldwidepedi-atricexperiences.AnnThoracSurg1999;8:10431051;discus-sion1052.AokiT,YamatoY,TsuchidaT,etal.Successfultrachealtrans-plantationusingcryopreservedallograftsinaratmodel.EurJCardiothoracSurg1999;16:169DupuitF,GaillardD,HinnraskyJ,etal.Differentiatedandfunctionalhumanairwayepitheliumregenerationintrachealxenografts.AmJPhysiolLungCellularMolPhysiol2000;278:ZhaoH,HuaTC,ZhouYZ,etal.Cryopreservationandtrans-plantationofdogtrachea.AnnNYAcadSci1999;858:270NakanishiR,HashimotoM,SoT,etal.Successfultracheocari-naltransplantation.JCardiovascSurg1999;40:591KunachakS,KulapaditharomB,VajardulY,RochanawutanonM.Cryopreserved,irradiatedtrachealhomografttransplanta-tionforlaryngotrachealreconstructioninhumanbeings.Oto-laryngolHeadNeckSurg2000;122:911BackerCL,MavroudisC,DunhamME,HolingerL.Intermediate-termresultsofthefreetrachealautograftforlongsegmentcongenitaltrachealstenosis.JPediatrSurg2000;35:818;discussion818BecharaFA,YabekSM,BermanW.Totaltrachealreconstruc-tioninathreemonth-oldinfant.JThoracCardiovascSurgBorrieJ,RedshawNR,DobbinsonTL.Silastictrachealbifur-cationprosthesiswithsubterminalDacronsuturecuffs.JTho-racCardiovascSurg1973;65:956NevilleWE,BolanowskiPJP,SoltanzadekH.Prostheticrecon-structionofthetracheaandcarina.JThoracCardiovascSurgBeallACJr,HarringtonOB,GreenburgSD,etal.TrachealreconstructionwithheavyMarlexmesh.ArchSurg1963;86:RushBF,ClifftonEE.Experimentalreconstructionofthetra-cheawithbladdermucosa.Surgery.1956;40:1105MarshakG,PorterJH,McAdamsAJ.Reconstructionofthecaninetracheawithurinarybladderwall.Laryngoscope1973;MorghissiK.TrachealreconstructionwithaprosthesisofMar-lexmeshandpericardium.JThoracCardiovascSurg1975;69:AngelC,MurilloC,ZwischenbergerJ,etal.Perioperativeextracorporealmembraneoxygenationfortrachealreconstruc-tionincongenitaltrachealstenosis.PediatrSurgInt2000;16:TrachealAgenesisJAmCollSurg