肛門直腸畸形大課

11三月2024肛門直腸畸形大課PediatricSurgeryMalformationdeformityabnormalitiesInflammationTraumaTumorHandAnusAlternativeNamesImperforateanus(indexword)CongenitalmalformationsoftheanusandrectumCongenital

anorectalmalformationAnalanomalyAnalatresia

Congenital

AnorectalMalformations

Incidence

Thenumbersarequitevariable:1/5000----1/1000Theaverageincidence:1in5000livebirthsChina:1/2800

2001JAmMedGenetics1846/4618840,4.05/10000,1/2500EuropeMale:Femaleabout1:0.7MostcommongastrointestinalmalformationsGeneralIntroductionThecauseofanorectalmalformationsisunknownGeneticandenvironmentalfactorsinteractoneachothertogiverisetoanorectalmalformationsGeneticsplayedanimportantroleintheoccurrenceofanorectalmalformations

EtiologyandEmbryologyThecloacaiscomposedofallantoisandhindgut(4w)

Theurorectalseptumdividesthecloacaintoananteriorurogenitalsinusandposteriorhindgut(5w)

Theurorectalseptumgrowstowardsthecloacalmembrane(5-7w)Theanalmembraneruptures,creatingtheanalopeningforthehindgut,itistheanus(8w)

Theurorectalseptumformstheperinealbody(8w)

EmbryologyIftheurorectalseptumdoesnotcompletelydividethecloaca,therectumwillconnectanteriorwithurinaryorgenitalstructures,resultinginanimperforateanuswithfistulaInsummary,congenitalanorectalmalformationsarecausedbyabnormalitiesinformationofthecloacaduringthefourthandeighthweeksofgestationEmbryology4thweek5-6thweek7-8thweekThedevelopmentoftherectumandanusInternalanalsphincterexternalanalsphincterlevatormusclepuborectalispubococcygeusmuscleiliococcygeusmuscleAnalsphinctermusclelevatormuscleinternalanalsphincterexternalanalsphincterInternalanalsphincterisathickenedcontinuationoftheinnercircularlayerofrectalmuscleIsinnervatedbyvisceralnervesResponsibleforpreventingthepassageofsolidandliquidstoolandgasSympatheticfibers---contraction--nostimulationofrectum—closetheanalcanalParasynpatheticfibers---relaxation--stimulationofrectumInternalanalsphincterExternal

analsphincterDeepExternal

analsphincterSuperficialExternal

analsphincterSubcutaneousExternal

analsphincterInnervatedbytheinferiorrectalbranchofthepudendalnerve(analnerveandperinealnerve)originatingintheanteiordivisionsofthesecondtofourthsacralnerverootspuborectalispubococcygeusmuscleiliococcygeusmusclelevatormuscleelevatestherectumpulltherectumforwardThepuborectalisistheportionmostcloselyassociatedwiththerectumAresuppliedbythefourthsacralneverandtheinferiorrectalorperinealbranchesofthepudendalnervesPuborectalis----

thethirdsphincterRectoanalangle

(about80°)Thevariousportionsofthelevatoranimusclearesurroundedtheanusandrectumandtendtopulltherectumforward,toelevatetherectum,formingtheanglebetweenthelongitudinalaxisoftherectumandtheanalcanal.ThisrectoanalanglehelpstomaintaincontinencebypreventingformedstoolfromenteringtheanalcanalStriatedmusclecomplexThismusclecomplexiscomposedofafusionofthepuborectalportionofthelevatoranimuscleandexternalsphinctermuscles,includingadeepexternalsphinctercomponent,whichcannotbeidentifiedclinicallyRectoanalAngleandStriatedMuscleComplexRectoanalAngleandStriatedMuscleComplexThelandmarkofclassificationofanorectalmalformationispubococcygealline(puborectalis)Therelationshipoftheendoftherectumtothepuborectalismuscledividestheimperforateanusintohigh,intermediateandlowtypesClassificationClassificationIftherectalpouchabove(supralevator)thelevatormuscle(puborectalis),itistermedahightypeIftherectalpouchat(translevator)thelevatormuscle(puborectalis),itistermedaintermediatetypeIftherectalpouchbelow(infralevator)thelevatormuscle(puborectalis),itistermedalowtypeThepropertreatmentofimperforateanusdependsonthetypethatisencounteredDeterminationofthelevelofthelesioniscriticalforappropriatemanagementEachtypeofanorectalmalformationrequiresadifferentoperationandmedicalmanagementClassificationWingspreadClassificationofAnorectalMalformation(1984)

High

AnorectalagenesisWithrectovaginalfistula

Withoutfistula

Rectalatresia

Intermediate

Rectovestibularfistula

Rectovaginalfistula

Analagenesiswithoutfistula

LowAnovestibularfistulaAnocutaneousfistula

Analstenosis

CloacaRaremalformations

LowAnocutaneousfistula

Analstenosis

RaremalformationsFemaleMale

High

AnorectalagenesisWithrectoprostaticurethralfistula

Withoutfistula

Rectalatresia

IntermediateRectobulbarurethralfistula

Analagenesiswithoutfistula

PediatrSurgInt(1986)1:200-205WingspreadClassificationofAnorectalMalformation(1984)StandardsforDiagnosisInternationalClassification(Krickenbeck2005)MajorclinicalgroupsRare/regionalvariantsPerineal(cutaneous)fistulaPouchcolonRectourethralfistulaRectalatresia/stenosisProstaticRectovaginalfistulaBulbarHfistulaRectovesicalfistulaOthersVestibularfistulaCloacaNofistulaAnalstenosisJPediatricSurgery,2005,40,1525OtherClassificationsAnaldeformitiesRectaldeformitiesLowtypeHightypeNointermediatetypeAnoperineal/anocutaneousfistulaAnoperineal/anocutaneousfistulaRectourethralfistulaRectovesicalfistulaAnoperinealfistulaRectovestibularfistulaRectovaginalfistulaPersistentcloacaPathologicalchangesareverycomplicatedSphinctermuscleNeverSacrumAssociatedanomaliesThehigherthedefect,thesevererthepathologicalchange,thelessthelikelihoodwillbeofachievingbowelcontrolPathologyVACTERLAssociation

VACTERLV vertebralA AnorectalC CardiacT Tracheo-esophagealfistulaE EsophagealatresiaR RenalL LimbAssociatedAnomaliesCardiovascularGastrointestinalSpinalandvertebralGenitourinaryGynecologicSymptomsarevariableDifferenttype:differentSymptomsThelevelofdistalpouchWithorwithoutfistulaSizeandpositionofthefistulaAssociatedanomaliesClinicalPresentationsNopassageoffirststoolwithin24to48hoursafterbirthLifelonghistoryofconstipationStoolpassedbywayoffistulaAbsenceofanalopeningMisplacedanalopeningVomitingandabdominaldistention

ClinicalPresentationsWithoutfistulaLowerintestinalobstructionNopassageofstoolorgasAbdominaldistentionandvomitingPhysicalexamination：NoanusFlatperineumwithbulgingoncryingNoexternalsphinctercontractiononscratchingtheperineumClinicalPresentationsWithfistulaMale：PassageofmeconiumintheurinePassmeconiumorflatusviapenisMeconiumpassedfromthefistulaintheperineumwithlowerobstructionFemale：AbnormalanalopeningPassstoolfromvestibulumorvaginaOnlyoneorificeintheperineum----cloacaClinicalPresentationsAnoperinealfistula:MeconiumpassedfromthefistulaintheperineumAnoperinealfistula:MeconiumpassedfromthefistulaintheperineumRectourethralfistulaPassageofmeconiumintheurinePassmeconiumorflatusviapenisFemale:imperforateanuswithfistulaImperforateanuswithoutfistulaImperforateAnusDiagnosis

HistoryFailuretopassmeconiumwithinthefirst24hoursoflifeLifelonghistoryofconstipationThoroughexaminationofperineumMustperformathoroughperinealinspectionThediagnosisiseasilymadebyhistoryandthoroughexaminationofperineumTheappearanceoftheperineumdoesnotnecessarilypredictwhetherthelesionislow,intermediateorhighDiagnosisstudiesThepurposesofspecificdiagnosisstudiesare:Todeterminetheleveloftheblindrectalpouchwhetherlow,intermediateorhightypeToidentifyanyassociatedfistulouscommunicationsTodeterminethepresenceorabsenceofanyothercongenitalanomaliesToassessthestatusofthelevatoranimuscleandanalsphinctermuscleDiagnosisstudiesX-rayCT/MRIFistulogramDistalcolostogramLoopogramOthersDiagnosisstudiesIfnoneoftheclinicalsignstodeterminethelocationoftheanorectalanomalyareevidentby24hours,performingaradiologictestcanhelpThissituationisonlynecessaryinabout10%ofpatientsthatwithoutfistulaLateralpelvicradiographyisperformedinbabieswhohavenoexternalevidenceoffistula,whopassnomeconiumafter24hours,andwhohavenomeconiumintheurineX-rayX-rayInvertogram(Wangensteen\Rice1930)UpsidedownlateralfilmPronecross-tablelateralradiographsI-point,isthelowestpointoftheischialtuberosity,representsthedeepestpointofthelevatoranimusclesThepubococcygeallineisthelinethatconnectstheupperborderofthesymphysispubisandsacrococcygealjunction,itrepresentstheupperlimitsofthelevatormusculature(puborectalissling).ItisthelandmarkforclassificationofanorectalmalformationThepubococcygealline(PCline)andI-pointPClineIpointAbovethePCline----highBelowtheIpoint-----lowBelowthePClineAbovetheIpoint----intermediateTheleveloftherectalpouchBowelskindistanceThedistancebetweentheendoftherectumandtheopaquemarkermeasuresmorethan2cm,itmeansthattherectumlieshighX-rayfilmsshouldbetakenmorethan12hoursoflifetoallowenoughtimeforbowelgastotheendoftheblindrectumThechildshouldbeheldverticallyupsidefor3minutesbeforethefilmistakenThehipshouldbekeptrelativelystraightPlaceanopaquemarkerontheperinealskintodenotethecutaneousleveloftheanusX-raypersistentcloacaFistulogramDistalColostogramRectovaginalfistulaRectourethralfistulaCT/MRISurgicalPrincipalThepropertreatmentofimperforateanusdependsonthetypethatisencounteredEachtypeofanorectalmalformationrequiresadifferentoperationandmedicalmanagementThetreatmentsometimesdependsontheexperienceofthesurgeonandgeneralconditionofthepatientTreatmentSurgicalPrincipal

Whattime?Emergentoperation:withoutfistulaorthinfistulacausingintestinalobstructionImperforate"perforate”anusDelayedoperation:withwidefistula,anoplastyuntil3-6monthsafterbirth

Whichprocedure?Colostomyornot?Lowtype(analdeformities) perinealanoplastywithoutcolostomyIntermediateand

hightype

(rectaldeformities) Colostomy LaparoscopyassistedpullthroughVsPSARP ClosureofColostomySurgicalPrincipal

PSARP

posteriorsagittalano-rectoplastyColostomyornot?Intermediateand

high

type

(rectaldeformities)high-----colostomyNowadays-------withnocolostomyLaparoscopyassistedpullthroughVsPSARPDependingontheexperienceofthesurgeonandgeneralconditionofthepatientPSARP