胎儿畸形

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Abdominal-WallDefects腹壁缺损
Chapter58BladderExstrophy膀胱外翻
Chapter59Body-StalkAnomaly体蒂异常
Chapter60CloacalExstrophy泄殖腔外翻
Chapter61EctopiaCordis异位心
Chapter62Gastroschisis腹裂
Chapter63Omphalocele脐膨出
Chapter64PentalogyofCantrellCantrell五联症
CHAPTER58BladderExstrophy
CONDITION
Exstrophyofthebladderhasbeenrecognizedforcenturies,butitwasnotuntilthe19thcenturythatsurgicalcorrectionwasfirstattempted（Halletal.1953）.Thefirstattemptsatdiversionofurineintothecolonweremadein1850,andthefirstsuccessfulclosureofbladderexstrophywasperformedin1862（Canningetal.1996）.Incontrasttopatientswithcloacalexstrophythathaveotherunrelatedabnormalities,infantswithbladderexstrophyhavedefectsconfinedtothebladder,abdominalwall,perineum,genitalia,andbonypelvis.
Atbirththediagnosisofbladderexstrophyiseasilymadebythepresenceofcharacteristicfindings.Thebladderplateprotrudesimmediatelybeneaththeumbilicalcord（Fig.58-1）.Therectusmusclesaredivergentduetoseparatedpubicbones.Thereisanoutwardrotationoftheinnominatebonesandeversionofthepubicrami（Sponselloretal.1991）.Thephallusisshort,withadorsalurethralplate,splayedglans,anddorsalchordee.Infemales,themonspubis,clitoris,andlabiaareseparatedandthevaginalorificemaybedisplacedanteriorly.Bilateralinguinalherniasarecommonlyseenatbirthbecauseofthelargeinternalandexternalinguinalringcausedbythesplayingoftherectusmusculatureandlackofobliquityoftheinguinalcanal.Hussmanetal.（1990）reportedthat56%ofmalesand15%offemaleshaveinguinalhernias.InareportbyPeppasetal.（1995）inpatientspresentingwithherniawithin1yearofprimaryclosure,10to53%oftheherniaswereincarcerated.

Figure58-1.Newbornmaleinfantwithbladderexstrophy,demonstratingthepresenceofalowumbilicalcordwithaprotrudingbladderplateandashortpeniswithasplayedglans.

Inbladderexstrophytheumbilicalcordinsertslowontheabdomenandtheanusandscrotumtendtobemoreanteriorlyplacedthannormal（seeFig.58-1）.Althoughtherectusabdominusmusclesinsertnormallyatthepubictubercles,thediastasisofthepubicsymphysisandlateraldisplacementoftheiliacbonescausessplayingoftherectusmuscles.Thislateraldisplacementoftherectusmuscleswidenstheinguinalcanal,predisposingtoindirectinguinalherniasinthesepatients（Connoretal.1989;Hussmanetal.1990;Stringeretal.1994）.Becausethebladderisexternal,theperitonealreflectionisdeeperinthepelvisthannormalandtheureterscoursedeeplythroughthepelvisandenterthebladderwithalmostnosubmucosaltunnel,whichpredisposesthemtovesicoureteralreflux（NisonsonandLattimer1968）.
Thepenisinmaleswithbladderexstrophyisshortandbroadbecauseofpubicboneseparation,whichpreventsthemidlinejoiningofthecorporacavernosa（seeFig.58-1）.Theoveralllengthofthecorporacavernosaisshortenedbutreasonablelengthmaybeobtainedwithepispadiasrepairfromthedeepcorporalbodies（Woodhouseetal.1984）.Thereisusuallyamarkeddorsalchordeeandthepenilecurvatureiscompoundedbyshorterdorsaltunicaalbuginea.Femaleswithbladderexstrophyhaveahemiclitorisoneachsideofthebladderandthevaginalorificemaybeduplicatedanddisplacedanteriorly（Damarioetal.1994）.Theuterusmaybeduplicated,butthefallopiantubesandovariesareusuallynormal.
Allpatientswithbladderexstrophyhavesomedegreeofpubicdiastasis,withthehipsrotatedoutward.Manypatientshaveawaddlinggaitinearlychildhood,butlong-termhiporgaitproblemsarerare.
Innormaldevelopmentthecloacalmembraneoccupiestheinfraumbilicalpositionoftheabdominalwall,andthisbilaminarmembraneisinfiltratedbymesenchymetoformthelowerabdominalmusculature.Thegenitalfoldsfusesuperiorlytoformthegenitaltubercle.ThemostwidelyacceptedtheoryforthecauseofexstrophyisbasedontheworkofMuecke（1964）,inchickembryos.Inthismodel,overgrowthorpersistenceofathickenedcloacalmembraneresultsintruncatedmesenchymalmigration.Laterruptureofthemembranewithoutthemesenchymalreinforcementresultsinexstrophy.Bladderexstrophyresultsiftheruptureoccursafterthedescentofurorectalseptum.Ifruptureoccursintheabsenceoftheurorectalseptum,thencloacalexstrophyoccurs.TheprenatalsonographicobservationbyLangeretal.ofanintactcloacalmembranethatsubsequentlyrupturedduringthesecondtrimestersuggeststhatthepresenceorabsenceoftheurorectalseptumandnottimingofmembranerupturedistinguishesbladderexstrophyfromcloacalexstrophy（Langeretal.1992）.
CHAPTER59Body-StalkAnomaly

CONDITION
Body-stalkanomalyisasevereabdominal-walldefectthatresultsfromabnormalitiesinthedevelopmentofthecephalic,caudal,andlateralembryonicbodyfolds.Thismaldevelopmentresultsintheabsenceorshorteningoftheumbilicalcordwiththeabdominalorganslyingoutsidetheabdominalcavityanddirectlyattachedtotheplacenta（Shalevetal.1995）.Body-stalkanomalywasfirstdescribedbyKermaunerin1906inanewbornwithanabdominal-walldefectconsistingofanamnioticsacthatcontainedviscera;theanteriorwallofthesacwasdirectlyattachedtotheplacentaandtherewasnoumbilicalcord.Otherthanthereferencesgivenintextbooksofpathology,body-stalkanomalywasnotappreciatedinthegeneralobstetricliteratureuntilthereportofLockwoodandcolleaguesin1986.
Aftergastrulation,theembryoconsistsofathree-layered,flat,ovalgerminaldisk.Therapidgrowthoftheembryo,especiallyalongthesagittalaxiscausesthegerminaldisktocurve.Throughcircumferentialfolding,theembryobecomescylindrical.Asaresultofthisprocess,thebodyoftheembryocloses,thebodystalkforms,andanintraembryoniccoelom（peritonealcavity）separatesfromanextraembryoniccoelom（chorioniccavity）（Giacoia1992）.Theamnioticcavity,whichisinitiallylocateddorsaltothegerminaldisk,growsrapidlyandeventuallyencirclesthefetus,obliteratesthechorioniccavity,andenvelopstheumbilicalcord.Theabnormalityinthefoldingprocesspreventsthisobliterationofthechorioniccavityandformationoftheumbilicalcord.Withoutanumbilicalcord,thefetusbecomesdirectlyattachedtotheplacentalchorionicplate.Thisbody-stalkanomalyconsistsofasacofamnionCmesodermthatcontainsthedisplacedabdominalorgans（Giacoia1992）.
Causesproposedforbody-stalkdefectincludeearlyamnionrupturewithdirectmechanicalpressureandamnioticbands（seeChapter101）,vasculardisruptionoftheearlyembryo,oranabnormalityinthegerminaldiskthatleadstotheformationofananomalousamnioticcavity.Intheearly-amnion-rupturetheory,theabdominal-wallandspinaldefectscouldbesecondarytothepassageofthelowerhalfofthefetalbodyintothecoelomiccavitythroughthedefectintheamnioticsac.Thefetushasnoroomtomoveandremainspracticallyattachedtotheplacenta.Limbamputationsandencephalocelecouldbesecondarytotheentrapmentofthefetalskulland/orlimbsinthecoelomiccavity（Daskalakisetal.1997）.Alternatively,earlygeneralizedcompromiseofembryonicbloodflowcouldleadtoafailureofclosureoftheventralbodywallandpersistenceofthecoelomiccavity（VanAllenetal.1987）.Thiscouldalsoleadtoaruptureofanunsupportedamnionandformationofamnioticbands.
CHAPTER60CloacalExstrophy

CONDITION
Cloacalexstrophyrepresentsaspectrumofrarecongenitalanomaliesthatarethoughttoarisefrommal-developmentofthecloacalmembrane,whichpreventsmigrationofmesenchymaltissueandimpedesnormaldevelopmentofthelowerabdominalwall.Thecloacalmembraneseparatesthecoelomiccavityfromtheamnioticspaceduringtheearlyembryogenicperiod.Thepositionandthetimingofthedisruptionofthecloacalmembranedeterminesthevariantoftheexstrophy.Forexample,inferiorperforationresultsinepispadias;midperforationresultsinclassicexstrophy;andthesuperiorperforationresultsinsuperior-vesiclefissure（Jeffs1987）.Whencloacalexstrophyispresentinitsclassicform,theconstellationofsevereabnormalitiesisamongthemostdifficultforthepediatricsurgeontoreconstruct.Itconsistsofexstrophyoftheurinarybladder,exstrophyofthesmallorlargeintestine,analatresia,hypoplasiaofthecolon,omphalocele,andanomalousgenitalia,withassociatedneural-tubedefectspresentin50%ofcases（Fig.60-1）（Fujiyoshietal.1987）.

Figure60-1.Appearanceofanewborngeneticmaleinfantwithclassiccloacalexstrophy.Theinfraumbilicalomphalocelecanbeseenatthesuperioraspectofthedefect.Thereisaprominentelephant-trunkdeformityprolapsedthroughoutthemidlineintestinalzone.Thewidelysplayedbifidpeniscanbeseenatthelateralaspectofthedefect.

Theanatomyincloacalexstrophyiscomplex,withaventralabdominal-walldefectconsistingofanomphaloceleatthesuperiormarginofthedefectandexposedbowelandbladderattheinferiorextent（Fig.60-2）.Thehemibladdersareseparatedinthemidlinebyazoneofintestinalmucosa.Eachhemibladdermayhaveaureteralorificeandtheintestinalzoneseparatingthehemibladdersmayhavetheorificesoftheproximalgutsuperiorlyandthedistalgutinferiorly,withoneortwoappendicealorificesinbetween（Warneretal.1993）.Theproximalbowelorificeoftenprolapsesinthecharacteristicelephant-trunkdeformity.Thedistalgutisablindpouch,astheseinfantsallhaveimperforateanus.Allgeneticallymalecaseshaveassociatedgenitalanomalies,includingundescendedtesticlesandabifidpeniswitheachhalfattachedtowidelyseparatedpubicrami（Johnstonetal.1966）.

Figure60-2.Schematicrepresentationdepictsthelocationofthevariouscomponentsofcloacalexstrophy.Theomphaloceleisatthesuperioraspectofthedefectandisnotseeninthisdiagram.Thehemibladdersareseparatedbyamidlineintestinalzonethathastheorificeoftheileumfromwhichprolapseofileumformstheelephant-trunkdeformity.Theremayalsobeoneortwoappendicealorificesaswellastheorificetothemoredistalblind-endingrectalpouch.Lateraltothemidlineintestinalzonearethehemibladders,whicheachhaveaureteralorifice.

Althoughcloacalexstrophywasrecognizedasearlyas1909,itwasnotuntil1960thatthefirstsuccessfulreconstructionwasreported（Rickham1960;Warneretal.1993）.Itisonlyinrecentdecadesthatrepairofthiscomplexanomalyhasbeenroutinelyundertaken.Foryearsmostinfantswereallowedtodiebecauseofthemultiplicityandcomplexnatureofthecongenitalanomalies（Molenaaretal.1996）.However,inthepasttwodecades,survivalafterreconstructionforcloacalexstrophyhasincreasedto90to100%,albeitwithsubstantialandlifelongphysicalandemotionalburdensforthesepatientsandtheirfamilies（Manzonietal.1987）.
Duringearlydevelopment,thecloacalmembraneseparatesthecoelomiccavityfromtheamnioticcavity.Thecloacaisfirstevidentinthemidlineasanareainwhichectodermandendodermareinopposition,withnomesoderminbetween.Bythefourthweekofdevelopment,thecloacalmembraneformstheanteriorwalloftheurogenitalsinusatthebaseoftheallantois.Cephaladandlateraltothecloacalmembranearetheprimordiaofthegenitaltubercle.Theseprimordiaenlargeandfuseinthemidlinesuperiortothecloacalmembranetoformthegenitaltubercle.Atthissametimethereisingrowthofmesodermtowardthemidline,increasingthedistancebetweenthebodystalkandthecloacalmembrane,settingupthedevelopmentofnormalinfraumbilicalbodywall.Thecloacabecomesdividedintotheurogenitalsinusandtherectumbytheurorectalseptum,whichextendsinamedialandcaudaldirectiontothecloacalmembrane（Pohlman1911;Pattenetal.1952）.
Pattenetal.（1952）suggestedthecaudal-displacementtheoryforthegenesisofcloacalexstrophy.Accordingtothistheory,abnormalcaudaldisplacementofthepairedprimordiaofthegenitaltubercleisresponsibleforcloacalexstrophy.Epispadiasalonewouldoccuriffusionoftheprimordiainthemidlineoccurredatthelevelwheretheurorectalseptumjoinsthecloacalmembrane.Exstrophyofbothbowelandbladderwouldoccurifevenfurthercaudaldisplacementoftheprimordiaoccurredatalevelcaudaltotheanalportionofthecloaca.Incontrast,Marshalletal.（1962）suggestedthewedgeeffectofanabnormallylargecloacalmembranebeingresponsibleforcloacalexstrophy.Thisabnormallylargecloacalmembraneactsasawedgetothedevelopingstructureoftheabdominalwall.Ruptureofthismembranepriortodescentoftheurorectalseptumandfusionofthegenitaltuberclesresultsinthemidlineinfraumbilicaldefect,exposureofbladderandbowelmucosa,withbifidandepispadicgenitalia.Inachickembryomodel,Muecke（1964）hasbeenabletodemonstratethataplasticgraftplacedintheregionofthecloacalmembraneproducedawedgedefectwithpersistentcloacalmembraneandvaryingdegreesofinfraumbilicaldefects.Thesetheoriesdonotaccountforinvolvementofbowel,prolapseofileum,andforeshortenedgutincloacalexstrophy.Magnus（1969）suggestedthataloopofmidgutorhindgutprolapsesbetweenbladderhalvesandbecomesstrangulated.Alternatively,Johnstonsuggestedthatthegrowthofthehindgutisrestrictedbyitsinvolvementintheexstrophy（Johnston1913）.
MorerecentlyBruchetal.observedsonographicprogressioninafetuswithadilatedcloacalabnormalityat18weeksofgestationassociatedwitholigohydramniosandhydronephrosis.Repeatultrasoundexaminationperformedat24weeksofgestationdemonstratedruptureofthecloacalabnormalitywithresolutionofboththehydronephrosisandoligohydramnios.Thisnewbornhadtheclassicfeaturesofcloacalexstrophy,challengingprevioustheoriesofitsembryogenesis（Bruchetal.1996）.
Cloacalexstrophyisassociatedwithanomaliesoforgansystemsotherthanthecentraldefectinupto85%ofcases（Hurwitzetal.1987）（Table60-1）.Anomaliesoftheurinarytractarecommonandinseveralseriesoccurredin42to60%ofcases（Hurwitzetal.1987;Johnstonetal.1966;Spencer1965;Tanketal.1970;Ziegleretal.1986）.Vertebralanomaliesoccurin48to78%ofpatients（Hurwitzetal.1987;Spencer1965;Tanketal.1970）andmyelodysplasiain29to46%ofpatients（Hurwitzetal.1987;Ziegleretal.1986）.
CHAPTER61EctopiaCordis
CONDITION
Thoracic-walldefectsarisefromfailureofpartorallofthesternumtodevelop.Thesedefectsmayinvolveonlythesternumormaybeassociatedwithmoresevereanomalies.Themoststrikingoftheseisectopiacordis.Ectopiacordisisdefinedastheheartinanextrathoracicposition.Ravitch（1985）hasclassifiedsternaldefectsintothreemajorgroups:cleftsternumwithoutassociatedanomalies,trueectopiacordis,andpentalogyofCantrell（seeChapter64）（Table61-1）.

TABLE61-1.RAVITCH'SCLASSIFICATIONOFSTERNALCLEFTS

Sternaldefectsarecommonlyassociatedwithectopiacordis.Aspectrumofsternaldefectsalsooccurswithoutdisplacementoftheheart（Skandalakisetal.1994）.Inrarecases,segmentsofthesternumareabsent.Thexiphoidprocessisthesternalelementmostcommonlyabsent.Byronetal.（1948）reportedacaseinwhichonlythemanubriumremained.MartinandHelsworth（1962）reportedacaseofclaviclesandupperribsattachedtoanabnormallysmallmanubriumseparatedfromlowerribsattachedtoasternumelement.Completeabsenceofallsternalelementsisrare,buthasbeenreported,andcanbesuccessfullyreconstructed（AspandS***oa1961）.Incontrasttoabsentsternalelements,failureofsternalfusionmayoccurwithwideseparationofallsternalelements.Thisismostoftenseenwithassociatedeventrationoftheheart.However,severalcaseshavebeenreportedwithnoherniationofthoraicvisceraandintactskincoveringthedefect（Greenbergetal.1991）.
SuperiorsternalfusionoccurswithaV-orU-shapedcleftintheuppersternum,withvariableextensioninferiorlyeventothelevelofthexiphoid.Ninecaseshavebeenreported,allwithskin-covereddefectsandstructurallynormalheartslocatedwithinthechestcavity.Fourofthesecaseshadhemangiomasoftheheadandneckandamidlinerapheindicatingamidlinefusiondefect（Jewittetal.1962）.
Over200casesofectopiacordishavebeenreportedintheliterature（Skandalakisetal.1994）.Ravitch（1985）hasclassifiedectopiacordisintofourtypesbasedonthepositionoftheheart:cervical（3%）,thoracic（64%）,thoracoabdominalectopia（18%）,andabdominalectopia（15%）.Theheartwasexposedin40%ofthesecasesorcoveredbyaserousmembrane（31%）orskin（27%）（Schao-Tsuetal.1957）.
Itisimportanttodistinguishtrueectopiacordisfromfailureofsternalfusioninwhichtheheart,thoughbeatingprominentlybeneaththeskin-coveredgap,iswithinthechestandisstructurallynormal.Manycasesreportedasthoracicectopia,withintactskin,aremorelikelyexamplesoffailureofsternalfusion.
ThoracoabdominalectopiacordisisbetterknownasthepentalogyofCantrellandisinpartamisnomer,giventhattheheartisnottrulyectopic.InpentalogyofCantrelltheheartisabnormallysitedwiththeapexorienteddown,butispositionedwithinthechestandthereforenotectopiacordis（seeChapter64）.Bothcervicalandabdominalectopiacordismayoccurwithoutasternalcleft.Abdominalectopiacordisdoesnotbelonginthisgroupofanomaliesbecausethedefectisdiaphragmaticanddoesnotinvolvethethoraxortheanteriorabdominalwall.
Intrueectopiacordis,internalcardiacanomaliesaregenerallytherule（Medina-Escobedoetal.1991）.KanagasuntheramandVerzin（1962）suggestedthattheembryologicbasisofectopiacordiawasexcessivepericardialcoelomformationandsubsequentdestructionofthetransverseseptumwithruptureoftheanteriorbodywallat6weeksofgestation.Thefrequencyofmajorintrinsiccardiacdefectsintrueectopiacordissuggeststheremaybeaprimarydefectinthesplanchnicmesoderm（Ravitchetal.1985）.
CHAPTER62Gastroschisis

CONDITION
Gastroschisis（Greekforbellycleft）isafull-thicknessdefectintheabdominalwallthatoccurssecondarytoincompleteclosureofthelateralfoldsduringthesixthweekofgestation（MooreandPersaud1993;MooreandStokes1953）.Atbirth,theevisceratedbowelcharacteristicallyhasathickedematousappearancedescribedbyMooreasa“peel”（Fig.62-1）.Thepeelinvolvestheserosaandiscomposedoffibrinandcollagen.Thepeelingastroschisisisthoughttobecausedbyexposuretoamnioticfluidcombinedwithconstrictionattheabdominal-walldefect（Amouryetal.1977,Amouryetal.1988;Kleinetal.1983;Langeretal.1990;Moore1992;Tibboeletal.1986a,Tibboeletal.1986b）.Duhamel（1963）theorizedthatgastroschisisoriginatesfromadiscreteteratogenicinsultresultinginanisolateddefectindifferentiationofthesomatopleuralmesenchyme.Othersarguethatgastroschisisresultsfromaninuteroruptureofanumbilical-cordherniaaftercompletionoftheinfoldintheanteriorabdominalwall,butbeforecompleteclosureoftheumbilicalring（Shaw1975）.Inuteroruptureoftheherniaofthecordthatresultedingastroschisissupportstheargumentforthisbeingacauseinatleastsomecases（Glicketal.1985）.AcongenitalweaknessontherightsideoftheumbilicalcordhasbeensuggestedasacausebydeVries（1980）.Prematureatrophyorabnormalpersistenceoftherightumbilicalveincouldpredisposetodisruptionofthesomatopleuraatitsjunctionwiththebodystalk,withresultingherniaofthecord.Becausegastrointestinaldefectssuchasatresiaassociatedwithgastroschisisarecausedbyvasculardisruptions,Hoymeetal.（1983）suggestedthatgastroschisismaybecausedbydisruptionoftherightomphalomesentericartery,whichconnectstheyolksacwiththedorsalaorta.Thefactthatgastroschisisalmostalwaysoccurstotherightoftheumbilicalringisconsistentwiththeselattertheories（Torfsetal.1990）.

Figure62-1.Newborninfantwithgastroschisisdemonstratingcharacteristic“peel.”

Asmaternalseruma-fetoprotein（MSAFP）screeninghasbecomeincorporatedintoroutineprenatalcare,morecasesofgastroschisisarebeingdetectedprenatally.ThisisduetotheassociationbetweenelevatedMSAFPlevelsandventralabdominal-walldefects（Brocketal.1979;Killametal.1991;McKeownetal.1953;Redfordetal.1985;Stilleretal.1990）.Inonestudy,Larsonetal.（1993）founda58%incidenceofmajorfetalcongenitalanomalieswhenextremelyelevatedMSAFPlevelswerefoundbetween15and20weeksofgestation.Tenpercentofthesewereduetoabdominal-walldefects.ThesensitivityofMSAFPscreeningforthedetectionofabdominal-walldefectsvariesdependingonthetypeofabdominal-walldefect,thegeographicalarea,andthecutoffvalueofMSAFPused.
MSAFPscreeninghasahighersensitivityfordetectinggastroschisisthanomphalocele.Inapopulation-basedstudyofMSAFPscreening,usingpatientsfromMaineandRhodeIsland,Palomakietal.（1988）foundthatthecombinedincidenceofgastroschisisandomphalocelewas4.5in10,000livebirths（excludingneural-tubedefects,twins,andautosomalchromosomalanomalies）.AteachcutoffofMSAFP,detectionrateswerehigherforgastroschisisthanforomphalocele.Forexample,atacutoffof2multiplesofthemean（MoM）,thedetectionratewasmorethan99%forgastroschisisand78%foromphalocele.Atcutoffvaluesof2.5MoMand3MoM,thedetectionratesweremorethan98%and71%,and96%and65%,forgastroschisisandomphalocele,respectively.Theoveralldetectionratesforomphaloceleandgastroschisisatthecutoffsof2MoM,2.5MoM,and3MoMwere89%,85%,and81%,respectively.ThemedianMSAFPvalueofthe20casesofgastroschisiswas7MoMandthemedianvalueforomphalocelewas4.1MoM（Palomakietal.1988）.Crandalletal.（1991）haveshownthatthehighertheMSAFPlevelthegreatertheprevalenceofadversefetaloutcome.Thelowerdetectionrateinomphaloceleislikelyduetothepresenceofanintactmembranecoveringtheabdominalviscerainunrupturedomphalocelesasopposedtothedirectexposureofboweltotheamnioticfluidingastroschisis.
Analysisofamnioticfluida-fetoproteinandacetylcholinesterase:pseudocholinesteraselevels（ratio<0.13）isverysensitiveindetectinggastroschisis（Goldfineetal.1989）.Humanchorionicgonadotropin（hCG）levelshavebeenmeasuredin16pregnancieswithabdominal-walldefects（12gastroschises,4omphaloceles）becausethismarkerisalreadybeingincreasinglyusedforfetalaneu-ploidyscreening.Itmayhaveutilityasanadditionalmarkerforthepresenceofabdominal-walldefects.Usingacutoffof2.3MoM,thedetectionrateusinghCGwas31%,ascomparedwith81%forMSAFP.Usingthetwomarkers,thedetectionrateincreasedto87.5%,byfindingoneadditionalcase（Schmidtetal.1993）.MoredataarenecessarytoevaluatetheusefulnessofhCGlevelstoprospectivelyidentifyabdominal-walldefects.
CHAPTER63Omphalocele

CONDITION
Omphaloceleisadefectintheventralabdominalwallcharacterizedbyanabsenceofabdominalmuscles,fascia,andskin.Thedefectiscoveredbyamembraneconsistingofperitoneumandamnionandcanvaryinsizefromafewcentimeterstomostoftheventralabdominalwall.Unlikegastroschisis,inomphalocele,theumbilicalcordinsertsintothismembraneatalocationfarfromtheabdominalwall（deVries1980）.Thedefectisthoughttobecausedbyanabnormalitythatoccursduringtheprocessofbodyinfoldingat3to4weeksofgestation（DimmickandKalouset1992）.Atthattime,3foldsoccursimultaneously,andeachisassociatedwithadistincttypeofomphalocele.Cephalicfoldingdefectsresultinahighorepigastricomphalocele.AnexampleofthisispentalogyofCantrell（seeChapter64）,whichconsistsofanepigastricomphalocele,anteriordiaphragmaticdefect,sternalcleft,pericardialdefect,andassociatedintracardiacdefects（Cantrelletal.1958）.Adefectinlateralfoldingresultsintheclassicomphalocele（Fig.63-1）withamidabdominaldefect.Adefectincaudalfoldingresultsinaloworhypogastricomphaloceleasseeninbladderorcloacalexstrophy（seeChapter58andChapter60）（Duhamel1963;Melleretal.1989）.Thespectrumofseverityofabdominal-wallabnormalitiescanvaryfromasmallumbilicalherniatoalargedefectwithextrusionoftheabdominalviscera.

Figure63-1.Classicappearanceofa22-week-oldfetuswithomphaloceleduetodefectinlateralfolding.（CourtesyofDr.JosephSemple.）
CHAPTER64PentalogyofCantrell

CONDITION
PentalogyofCantrellisanunusualformofabdominal-walldefectthatconsistsoffiveassociatedanomalies,including:（1）midlineepigastricabdominalwalldefect,（2）defectofthelowersternum,（3）deficiencyoftheanteriordiaphragm,（4）defectinthediaphragmaticpericardium,and（5）intracardiacdefects.ThisconstellationofanomalieswasfirstdescribedbyCantrelletal.（1958）,hence,thetermpentalogyofCantrell,althoughithasalsobeenreferredtoastheCantrellCHallerCRavitchsyndromeandperitonealpericardialdiaphragmatichernia.AlthoughpentralogyofCantrellhasbeenusedinterchangeablywithectopiacordis,intheiroriginaldescriptionCantrelletal.（1958）werecarefultodistinguishbetweenthesetwoanomalies（seeChapter61）.
Cantrellsuggestedthatthedefectsinthissyndromefellintotwogroupsbymechanismofembryologicdevelopment.Inthefirstgroup,adevelopmentalfailureofmesodermresultsindiaphragmatic,pericardial,andintracardiacdefects.Thediaphragmaticdefectisafailureofthetransverseseptumtodevelop.Thepericardialdefectarisesfromthesomaticmesodermimmediatelyadjacenttotheregionofthesamelayerfromwhichthetransverseseptumdevelops.Defectivedevelopmentofonebutnottheotherofthesestructuresispossibleonlywithhighlyspecificlossofsomaticmesoderm.ThisisrarelyseeninpentalogyofCantrell,andthesedefectsoccurtogetherinmostpatients.Theintracardiaclesionsresultfromabnormaldevelopmentoftheepimyocardium,whichisderivedfromthesplanchnicmesoderm.Whiletheresultingintracardiacdefectsvary,almostallincludedefectsofthecardiacsepta.
Thesecondgroupofdefectsresultsfromfailureoftheventralmigrationoftheperiprimordialstructuresandincludethesternaldefectandtheepigastricomphalocele.Allelementsofthesternumarepresent,andthecostocartilagesconnectwiththecartilaginousplates,whichrepresentthepairedsternalanlagenwithvariabledegreesoffusion.Thesternaldefectresultsnotfromanabsenceofsternalprimordiabutfromthefailureofpairedsternalanlagentocompletemigration.Asimilarfailureofmigrationresultsintheabdominal-walldefect.Thenormallayersoftheventralabdominalwallarepresent,butthereisalackofventralmigrationofthemyotomes.Thesepatientshavestructurallynormalrectusabdominusmusclesthatcorrectlyattachtothepubicsymphysis,butdeviatelaterallyastheyruncephaladtoinsertintothecostalmarginsatthemidclavicularline.Thislackofmigrationisthoughttobeduetoadefectivedevelopmentoftheparamedianmesoderm.
TheheartinpentalogyofCantrellisnormallypositionedwithinthechest.Incontrast,ectopiacordisischaracterizedbyabnormalpositionoftheheartoutsideofthechest（seeChapter61）.Thisbecomesconfusing,asclassificationsystemsforectopiacordislistthreetypes:cervical,thoracic,andthoracoabdominal,whichisthesameaspentalogyofCantrell.Ectopiacordismayencompasspartialorcompletesternaldefects,andinvariablyincludesintracardiacanomalies,butdoesnotincludethepericardial,diaphragmatic,andabdominal-walldefectsseeninthepentalogyofCantrell.KanagusuntheramandVerzin（1962）suggestedthatectopiacordisoccursasaresultofexcessivepericardialcoelomformationandsubsequentdestructionofthetransverseseptumwithruptureoftheanteriorbodywallat6weeksofgestation（KanagusuntheramandVerzin1962）.Ravitch（1986）hassuggestedthatthehighfrequencyofmajorintrinsiccardiacdefectswithtrueectopiacordisindicatesthatthereisaprimarydefectinthesplanchnicmesodermresponsibleforcardiacdevelopment.
Theprimitivethoracicwallconsistsofsomatopleuracoveringtheventralwallofthepericardialcavity.Theectodermallayerofthesomatopleuraformstheskin,buttheremainderofthecomponentsofthebodywallderivefrominvadingdorsalmesodermduringthesixthweekofgestation.Thesternumappearsastwoparallelcondensationsofmesenchyme,thelateralsternalbands.Amediancranialcondensation,thepresternum,appearsindependently.Thelateralsternalbandsfusewiththepresternumcraniallyandwiththetipsoftheribslaterally.Duringtheseventhweek,thesternalbandsbeginfusingattheircephalicendandproceedcaudallyandceasebytheninthortenthweek.
Fetology_-_Diagnosis_and_Management_of_the_Fetal_Patient_1st

上述内容来源
我曾经听过一个胃壁肌层缺损的孩子（当时不在班）,有什么好的产前诊断方法吗?
先试着翻译一小段，非本专业的好难啊，请版主多多修改。
CHAPTER58BladderExstrophy
CONDITION
Exstrophyofthebladderhasbeenrecognizedforcenturies,butitwasnotuntilthe19thcenturythatsurgicalcorrectionwasfirstattempted（Halletal.1953）.Thefirstattemptsatdiversionofurineintothecolonweremadein1850,andthefirstsuccessfulclosureofbladderexstrophywasperformedin1862（Canningetal.1996）.Incontrasttopatientswithcloacalexstrophythathaveotherunrelatedabnormalities,infantswithbladderexstrophyhavedefectsconfinedtothebladder,abdominalwall,perineum,genitalia,andbonypelvis.
Atbirththediagnosisofbladderexstrophyiseasilymadebythepresenceofcharacteristicfindings.Thebladderplateprotrudesimmediatelybeneaththeumbilicalcord（Fig.58-1）.Therectusmusclesaredivergentduetoseparatedpubicbones.Thereisanoutwardrotationoftheinnominatebonesandeversionofthepubicrami（Sponselloretal.1991）.Thephallusisshort,withadorsalurethralplate,splayedglans,anddorsalchordee.Infemales,themonspubis,clitoris,andlabiaareseparatedandthevaginalorificemaybedisplacedanteriorly.Bilateralinguinalherniasarecommonlyseenatbirthbecauseofthelargeinternalandexternalinguinalringcausedbythesplayingoftherectusmusculatureandlackofobliquityoftheinguinalcanal.Hussmanetal.（1990）reportedthat56%ofmalesand15%offemaleshaveinguinalhernias.InareportbyPeppasetal.（1995）inpatientspresentingwithherniawithin1yearofprimaryclosure,10to53%oftheherniaswereincarcerated.

Figure58-1.Newbornmaleinfantwithbladderexstrophy,demonstratingthepresenceofalowumbilicalcordwithaprotrudingbladderplateandashortpeniswithasplayedglans.

Inbladderexstrophytheumbilicalcordinsertslowontheabdomenandtheanusandscrotumtendtobemoreanteriorlyplacedthannormal（seeFig.58-1）.Althoughtherectusabdominusmusclesinsertnormallyatthepubictubercles,thediastasisofthepubicsymphysisandlateraldisplacementoftheiliacbonescausessplayingoftherectusmuscles.Thislateraldisplacementoftherectusmuscleswidenstheinguinalcanal,predisposingtoindirectinguinalherniasinthesepatients（Connoretal.1989;Hussmanetal.1990;Stringeretal.1994）.Becausethebladderisexternal,theperitonealreflectionisdeeperinthepelvisthannormalandtheureterscoursedeeplythroughthepelvisandenterthebladderwithalmostnosubmucosaltunnel,whichpredisposesthemtovesicoureteralreflux（NisonsonandLattimer1968）.
Thepenisinmaleswithbladderexstrophyisshortandbroadbecauseofpubicboneseparation,whichpreventsthemidlinejoiningofthecorporacavernosa（seeFig.58-1）.Theoveralllengthofthecorporacavernosaisshortenedbutreasonablelengthmaybeobtainedwithepispadiasrepairfromthedeepcorporalbodies（Woodhouseetal.1984）.Thereisusuallyamarkeddorsalchordeeandthepenilecurvatureiscompoundedbyshorterdorsaltunicaalbuginea.Femaleswithbladderexstrophyhaveahemiclitorisoneachsideofthebladderandthevaginalorificemaybeduplicatedanddisplacedanteriorly（Damarioetal.1994）.Theuterusmaybeduplicated,butthefallopiantubesandovariesareusuallynormal.
Allpatientswithbladderexstrophyhavesomedegreeofpubicdiastasis,withthehipsrotatedoutward.Manypatientshaveawaddlinggaitinearlychildhood,butlong-termhiporgaitproblemsarerare.
Innormaldevelopmentthecloacalmembraneoccupiestheinfraumbilicalpositionoftheabdominalwall,andthisbilaminarmembraneisinfiltratedbymesenchymetoformthelowerabdominalmusculature.Thegenitalfoldsfusesuperiorlytoformthegenitaltubercle.ThemostwidelyacceptedtheoryforthecauseofexstrophyisbasedontheworkofMuecke（1964）,inchickembryos.Inthismodel,overgrowthorpersistenceofathickenedcloacalmembraneresultsintruncatedmesenchymalmigration.Laterruptureofthemembranewithoutthemesenchymalreinforcementresultsinexstrophy.Bladderexstrophyresultsiftheruptureoccursafterthedescentofurorectalseptum.Ifruptureoccursintheabsenceoftheurorectalseptum,thencloacalexstrophyoccurs.TheprenatalsonographicobservationbyLangeretal.ofanintactcloacalmembranethatsubsequentlyrupturedduringthesecondtrimestersuggeststhatthepresenceorabsenceoftheurorectalseptumandnottimingofmembranerupturedistinguishesbladderexstrophyfromcloacalexstrophy（Langeretal.1992）.

膀胱外翻
几个世纪前人们就对膀胱外翻有所认识，但直到19世纪外科矫形手术才最初应用于此。1850年人们实施了第一例尿流改道结肠手术，并且在1862年首例膀胱外翻修复术得以成功实施。生殖道外翻患者常合并其他与之无关的畸形，与其不同的是，患有膀胱外翻的患儿病变则主要表现在膀胱，腹壁，会阴，外生殖器和骨盆的缺陷。
通过一些特征性体征可以很容易的对新生儿做出膀胱外翻的诊断。膀胱外翻患儿可见在脐带下有膀胱的凸出。（图58-1）耻骨的分离常导致耻骨直肠肌的分岔，膀胱外翻还常合并耻骨支的外旋和外翻。阴茎短小常伴随尿道板背曲，尿道龟头型下裂，以及痛性阴茎勃起，女性患者常发生阴阜，阴唇，阴蒂分裂，以及阴道口前移。患儿在出生时常可被发现患有双侧腹股沟斜疝，因为直肠肌的分岔和腹股沟管倾斜度的缺乏常导致腹股沟内外环的增大。HUSSMAN等报导了56%男性患者和15%女性患者发生腹股沟斜疝。在PEPPAS等的一项报导中，1岁内进行初次修复手术的膀胱外翻合并疝的患者中，有10-53%的患者疝自愈了。
图58-1男性新生儿合并膀胱外翻，显示脐下凸出的膀胱以及短小的阴茎和尿道下裂。
膀胱外翻患者脐部位于腹部部位下移，会阴和阴囊位置较正常上移。虽然腹直肌正常附着在耻骨结节上，但耻骨联合分离和髂骨侧移使腹直肌分散。侧移分散的腹直肌增宽了腹股沟管使患者更易罹患间接腹股沟疝。由于膀胱外翻使腹膜反折较深而将尿道推向盆底深处穿行几乎进入膀胱时没有粘膜下开口，这使其更易罹患膀胱输尿管反流。
膀胱外翻男性患者由于耻骨分离导致阴茎短小而粗，因为其阻碍了海绵体在中线的融合（见图58-1）。行尿道上裂修复术后海绵体总体长度有所缩短但仍能保持合理的长度。患者阴茎背侧白膜缩短常常导致严重的阴茎弯曲和痛性阴茎勃起。女性膀胱外翻患者阴蒂分裂在膀胱两侧并且可能合并双阴道及阴道口前移。子宫也可能为双子宫，但输卵管及卵巢常常是正常的。
所有膀胱外翻患者都有不同程度的耻骨分离以及髋骨外翻。许多患者在幼年早期时行走可出现鸭步，但这些问题很少有长期存在的。在正常生长发育时泄殖腔膜长入脐下腹壁，并且这种双层膜与间质一起行成了腹壁浅肌层，生殖皱襞很好得融合行成生殖结节。对外翻的成因，目前行成的共识是基于MUECKE一项对鸡胚的研究。在这一模型中，厚厚的泄殖腔膜因为过度和持久的生长，导致了缩短的间质的移位。接下来由于缺乏强有力的间质得支持，膜状组织的断裂，最终导致了外翻的行成。如果泄殖腔膜断裂发生在尿直肠膈下降后，则形成了膀胱外翻。如果断裂发生在尿直肠膈下降之前，则行成了泄殖腔外翻。LANGER等学者通过B超对产前早期完整的泄殖腔膜到孕中期地断裂这个过程得观察，提示了尿直肠膈的存在或者缺失以及泄殖腔膜的破裂发生的不同时间可以用以区别膀胱外翻以及泄殖腔外翻
学习了...........学习了...........
胎儿前腹壁畸形是指前腹壁皮肤肌层的异常发育所导致的各种畸形。前腹壁畸形的发生率不到1／3000，脐膨出和内脏外翻是最常见的前腹壁畸形，其他前腹壁畸形，如Beckwith―Wiedemam综合征、泄殖腔外翻、羊膜带综合、肢体体壁综合征、Cantrell五联症则相对少见。Prune一belly综合征也是一种较半见的下腹壁畸形。
胚胎发育
腹壁在胚胎早期由四个中胚层皱襞形成，即头襞、尾襞及两侧襞。四个皱襞同时发展，最后在中央汇合形成脐环。胚胎早期原始消化道（原肠）由卵黄囊发育而成，原肠中段与卵黄囊之间有卵黄管相连，卵黄管对中肠起牵拉作用，逐渐变细、毕塞呈条索状或消失（图13―1―1）。胚胎第6~10周时，消化道生长速度超过腹腔及腹壁的生长速度，此时中肠被挤到脐带底部，形成生理性中肠疝。

胚胎10周以后，腹腔生长速度增快，腹腔容积扩大，腹前壁的头襞、尾襞及侧襞皮肤及肌肉迅速从背侧向中线靠拢、接近、折叠，原突出体腔外的中肠此时逐渐向腹腔内回复，并开始中肠的旋转，在胚胎12周时，完成正常肠管的旋转，同时腹壁在少央汇合形成脐环（图ll一1―2）。

如果在上述发育过程中、胚胎受到某些因素影响，将发生各种腹壁畸形。有许多理论用来推断这些畸形缺陷的原因，其中有两个基本的机制：血管闭塞病变和胚胎折叠异常，两者可单独或共同引起前腹壁畸形。在腹裂和羊膜带综合征，可能是由血管闭塞退变单个因素引起，其他大多数腹壁缺陷是由两个因素共同引起。头襞发育缺陷，可产生Centrell联征，Centrell五联征包括脐以上腹中线缺陷引起的脐膨出、异位心、胸骨缺陷、心包和前隔缺陷，其合并的常见先心病有心内膜垫缺损、法洛四联征。侧襞发育缺陷，可发生脐膨出、腹裂。尾襞发育缺陷，可发生脐膨出、膀胱外翻、小肠膀胱裂、肛门直肠闭锁。如果头、尾襞同时发育缺陷，特产生广泛的胸、腹联合裂畸形。如果腹壁肌肉发育缺陷则发生Prune-belly综合征，Prune-belly综合征主要表现为膀胱过度扩张、输尿管扩大、下腹壁肌层缺乏导致腹部异常膨隆。
头、尾襞的缺陷较其他类型的缺陷预后更差，在中期妊娠，有30％内脏外翻属于此两种类型缺陷，仅15％继续妊娠于晚期妊娠，该种类型的缺陷病死率较高。
脐膨出是先天性前腹部发育不全，在正中线出脐带周围肌肉、皮肤缺损，致使腹膜及腹腔内器官一起膨出体外，疝出内容物的表面覆盖一层很薄的膜，为部分羊膜和腹膜，在两层膜之间有华腾胶。

脐膨出的发生率为1/4000~1/5000。男性较女性略多，约为3:2.

畸形特征
如果外胚层和中胚层褶在胚胎第4周时沿中线融合失败，即可能产生脐膨，可能伴有膀胱外翻。

也有研究认为含有肝脏的脐膨出的病理机制不同于含有肠管的脐膨出，后者是指继发于孕12周以后的初始体蒂的持续存在，由于中肠疝回纳腹腔失败所致。相反，含有肝脏的脐膨出系由于在胚胎形成期一侧体褶的发育受阻而引起。大的脐膨出很可能由于胚胎形成时的较早期缺陷，小的脐膨出可能发生在稍晚期。

病理上根据脐膨出及腹壁缺损的大小，将脐膨出分为巨型和小型两种。
1.巨型脐膨出此种脐膨出是腹侧中胚层四个襞在胚胎10周前出现体层发育停顿所致。本型腹壁缺损宽，直经多大于5cm，腹腔容积极小，中肠全部膨出，肝脏、脾脏、胰腺、小肠、胃均可膨出。

2.小型脐膨出本型脐膨出是腹壁体层在孕10周后发育停顿，故腹壁缺损小，直经小于5cm，体腔发育已有一定容积，部分中肠已回纳入腹腔，并开始肠管的旋转，仅有肠管等内容物膨出。
脐膨出合并其他畸形很常见，高达50%的病例可能存在心脏、肾脏、胃肠道、面部、神经管、

肢体缺陷。
另外疝出物的内容物与染色体的异常有关，含有肝脏的脐膨出较仅有肠管的脐膨出染色体异常的发生率低，然而在两种情况下，遗传危险性均较正常妊娠大。小型脐膨出主要与18-三体、13-三体、三倍体、Rlineey综合征有。脐膨出是预测非整倍体和其他结构缺陷的一个可靠的指标之一。

脐膨出的预后很大程度上取决于合并畸形及其严重程度。如果存在较严重的合并畸形或者染色体的异常，或者二者均存在，则围生儿的病死率高达80%~100%。
腹裂
腹裂（gastroschisis）也称内脏外翻，是与腹腔脏器（如肠管）外翻有关的一侧前腹壁全层缺陷的先天畸形。发生率为1/3000。
腹裂是腹壁全层完全性缺陷，在晚期妊娠缺陷直经常为2~2.5cm。大多数情况下，缺陷位于脐带的右侧（在远离胎儿胃的脐带的一侧）。少数可位于左侧。腹裂的脏器外翻主要是肠外翻，其他可能外翻的器官包括膀胱、子宫、卵巢、胃、胆囊等，肠动脉闭锁或狭窄约占25%，肠缺血可能导致肠穿孔引起胎粪性腹膜炎。

1.通常显示脐带入口右侧的腹壁皮肤强回声线连续性中断，并可测量回声中断的直经大小，一般为2~3cm，少数腹壁缺损位于脐旁左侧腹壁。
2.胃、肠等腹腔内脏器外翻至胎儿腹腔外，其表面无腹膜覆盖，在羊水内自由漂浮。
3.由于胃肠等腹腔内容物外翻至腹腔外羊水内，故腹腔内容物少，腹腔空虚，腹围小于相应孕周大小。
4.脐带腹壁入口位置正常，通常位于突出内容物的左侧前腹壁。
5.外翻的肠管有时可见局部阶段性扩张，管壁增厚，蠕动差，肠内容物多含致密低回声光点，这与继发的肠畸形有关，如肠闭锁、肠扭转。肠梗阻。
6.羊水过多、羊水内有较多低回声光点翻动。
7.用彩色多普勒超声可鉴别突出的肠管和脐带。
8.当外翻的内容物仅为少量肠管、且胎儿为正枕前位时，有时易误将肠管误认为胎儿男性外生殖器，应注意鉴别。
9.相对于脐膨出而言，腹裂合并其他先天性畸形不常见，其他畸形如房间隔缺损、室间隔缺损。肾发育不全等可偶然与腹裂合并存在。

预后
有85%~95%的新生儿生存，且新生儿结局与进入羊膜腔内的小肠数量无关。据文献报道腹裂胎儿宫内病死率为10.6%
体蒂异常（Bodystalkanomaly）为致死性畸形，也称为肢体－体壁综合征，其确切病因不明，有学者认为是由于早期偶发羊膜破裂形成的系列征，在妊娠5周左右胚胎包卷异常，胚外体腔不能消失，羊膜腔形成异常而导致体蒂形成失败，造成无脐部，无脐带，严重腹壁缺损畸形，胎儿的腹内脏器均在腹腔之外，严重者胸腔脏器也可裸露在外，表面覆盖片状羊膜。胎儿内脏直接与胎盘相连，无脐带，其间的脐血管往往很短且只有一根脐动脉，胎儿腹侧与胎盘相贴，胎体强直，易继发骨骼畸形如脊柱前或后凸、侧凸、下肢畸形等。母血及羊水中AFP极度升高。超声检查可发现胎儿的多发畸形，常见的异常声像图为：①孕14周前可见胎儿上半身在羊膜腔内，下半身在胚外体腔内；②胎儿巨大腹壁缺损，肝脏和小肠等腹内脏器疝出；③肢体变形；④脊柱严重的前后侧凸；⑤脐带非常短，常为单脐动脉。此外由于胎体固定在胎盘上，胎动极少，胎儿体位基本不变。诊断中要与羊膜束带综合征、巨大腹裂、脐膨出，泄殖腔外翻等鉴别（老杏战友已作详细说明），后几者虽也有腹腔脏器外露，但脐带往往正常，且部分合并染色体异常，综合分析不难鉴别。

肢体－体壁综合症，也称体蒂异常（bodystalkanomaly）

畸形特征为：
广泛前侧腹壁裂、明显的脊柱侧突、肢体畸形、颜面畸形、脐带极短，上述畸形可单独存在或合并存在，其特征性表现为羊膜绒毛膜不融合。

预后较差，常为致死性。无复发风险。

肢体－体壁综合征，其确切病因不明，有学者认为是由于早期偶发羊膜破裂形成的系列征，在妊娠5周左右胚胎包卷异常，胚外体腔不能消失，羊膜腔形成异常而导致体蒂形成失败，造成无脐部，无脐带，严重腹壁缺损畸形，胎儿的腹内脏器均在腹腔之外，严重者胸腔脏器也可裸露在外，表面覆盖片状羊膜。胎儿内脏直接与胎盘相连，无脐带，其间的脐血管往往很短且只有一根脐动脉，胎儿腹侧与胎盘相贴，胎体强直，易继发骨骼畸形如脊柱前或后凸、侧凸、下肢畸形等。母血及羊水中AFP极度升高。超声检查可发现胎儿的多发畸形，常见的异常声像图为：①孕14周前可见胎儿上半身在羊膜腔内，下半身在胚外体腔内；②胎儿巨大腹壁缺损，肝脏和小肠等腹内脏器疝出；③肢体变形；④脊柱严重的前后侧凸；⑤脐带非常短，常为单脐动脉。此外由于胎体固定在胎盘上，胎动极少，胎儿体位基本不变。诊断中要与羊膜束带综合征、巨大腹裂、脐膨出，泄殖腔外翻等鉴别（老杏战友已作详细说明），后几者虽也有腹腔脏器外露，但脐带往往正常，且部分合并染色体异常，综合分析不难鉴别。

部分内容取自超声版。
无脐带是很罕见的一种情况.。这种发育导致胎盘与胎儿腹壁直接相连，合并内脏外翻，是一种致死性畸形。其发病原因和病理性变应该像“学生1”的描述：体蒂形成失败，特点是无脐部，无脐带。主要是胚胎早期（2--3周）体蒂未能正常发育或发育异常所致。

体蒂形成失败，特点是无剂部，无剂带。病理上，体蒂异常的胎儿内脏均在腹腔之外，严重者胸腔脏器也可裸露在外，胎儿内脏直接与胎盘相连，其间有脐血管，往往很短且只有一条脐动脉。由于无脐带使胎儿腹侧与胎盘相贴，胎体强直易继发骨骼畸形如脊柱前凸、侧凸、下肢畸形等。一般情况下体蒂异常不伴有染色体畸形。
腹壁缺损的几个概念：
脐膨出：为腹壁中线包括肌肉、筋膜和皮肤的缺损，腹腔内容物突入脐带内，表面覆盖以腹膜和羊膜。发病率1：4000--1：5800活产。

脐疝与脐膨出鉴别要点为：脐疝表面有皮肤及皮下脂肪覆盖，脐带连接部正常，绝大部分婴儿无需手术自然关闭。（指婴儿脐疝）

腹裂：是指脐旁腹壁全层缺损，伴腹腔内脏突出，表面无腹膜与羊膜覆盖，直接裸漏在羊水中。发病率1：10000--1：15000活产。

生理性中肠疝：妊娠7-8周，体蒂与卵黄蒂形成脐带，迅速延长的中肠形成了中肠袢突入脐带根部，宽度7mm以内。
讨论一下几种腹壁缺损的区别（根据搜集资料整理）：
1.脐膨出：为腹壁中线包括肌肉、筋膜和皮肤缺损，腹腔内容物突入脐带内，表面覆盖以腹膜和羊膜。

脐膨出的原因是胚胎时期外胚层皮肤向中线包卷失败，腹壁中线缺损，腹腔脏器通过脐根部突入脐带内。肠管、胃泡、肝脏是最常见的脐膨出内容物。膨出物表面覆盖有两层膜：内层为腹膜，外层为羊膜。脐带连接于膨出物。

大多数脐膨出合并其他先天畸形。据文献报告，30%-50%伴有胃肠道畸形，50%合并心血管畸形，40%-60%脐彭出可检出染色体畸变，常见为13-三体、18-三体、21-三体，Turner综合征（先天性卵巢发育不全）、Klinefelter综合征（先天性睾丸发育不全）、三倍染色体。

超声表现为腹前壁脐部外突性包块，表面覆以包膜，内为腹腔或胸腔结构，脐带进入包块内，常伴有羊水过多和其它胎儿畸形。

2.腹裂：是指脐旁腹壁全层缺损，伴腹腔内脏突出；腹裂大部分为散发性，也有家族史报道，但少有染色体异常。目前，一般认为腹裂与脐静脉或脐肠系膜动脉受损有关。
腹裂的特点为脐旁腹壁的全层缺损，而脐带与腹壁相连处为正常。通常，病损主要见于脐右侧，缺损往往较大，大都在2-4cm之间。突出的腹腔内脏主要是肠管，极少有肝脏或泌尿道脏器的外突。
声像图表现：腹壁缺损常常位于脐根部的右侧。缺口一般较小，而脐根部结构显示正常。突出的内脏表面无膜覆盖。突出的脏器多为肠管，可多可少。突出的肠管漂浮在羊水中，肠管壁水肿增厚，管腔有轻度扩张改变。CDFI:脐血流示入脐部位基本正常。若大量肠管外突，胎儿腹围、胸围变小。当并发肠梗阻时，声像图显示腹腔内外的肠管均明显扩张。有时胃泡也显示有明显的扩张，羊水出现增多改变。肠穿孔时，声像图表现为羊水混浊，有大量漂浮物，与胎粪性腹膜炎相似。

3.脐疝：表现为圆形或卵圆形的脐部局限性肿块，有皮肤覆盖。脐疝病变范围小，膨出物为肠管，脐疝表面有皮肤及皮下脂肪覆盖。有学者把它与脐膨出看作是同一种病。

4.脐膨出-巨舌-巨大躯体综合征（Exomphalosmacro-Glossia-GigantismSyndrome）：为先天性遗传性疾病。除脐膨出还表现躯体巨大尤其是腹部膨大。出生后亦称新生儿低血糖-巨舌-内脏肥大-脐膨出综合征、新生儿低血糖伴内脏肥大-巨舌-小脑综合征。

脐彭出与腹裂的鉴别：

1.缺损部位：腹裂多位于中线旁，右侧多见；脐膨出位于中线处。

2.肿块表面是否有包膜覆盖：腹裂无覆盖物；脐彭出有完整包膜覆盖。

3.脐带与肿块的位置：腹裂时脐带从脐空处入肝脐静脉；脐膨出时脐带首先入肿块。

4.疝出的脏器：腹裂主要是小肠，肝一般不疝出；脐膨出常有肝脏膨出。

5.大多数脐膨出合并其他先天畸形；腹裂除合并肠旋转不良和空回肠闭锁外，合并其他畸形者较脐彭出少。

6.脐膨出表面覆盖的膜，在一定程度上限制了AFP的漏出，AFP正常或轻度增高；腹裂因腹壁缺损使胎儿甲胎蛋白（AFP）大量漏出，因此，77%母血AFP明显升高。

整理过程中，可能因了解不深入形成观点的偏差或失误，敬请斧正。（老杏同志的）

这里的许多内容，源自超声版。各位可以自己搜一下。

我把有关腹壁缺损的东西在这里总结了一下。
膀胱外翻和泄殖腔外翻
　　膀胱外翻是指膀胱前壁缺如，膀胱后壁暴露在外。泄殖腔外翻则更为复杂，由于尿直肠隔发育障碍，泄殖腔未能分隔成肛直肠管和尿生殖窦，累及泌尿道和肠道两个系统的异常。
　　膀胱外翻除了膀胱后壁翻出外，还有耻骨联合分离、脐孔低、男性睾丸不完全下降、阴茎短小及尿道上裂。女性胎儿则有阴蒂裂。泄殖腔外翻时，外翻的组织中间为肠内壁而双侧为膀胱内壁，并各有一输尿管开口。
　　膀胱外翻的声像图主要表现是下腹壁显示软组织包块，无正常膀胱显示。由于腹壁缺损不会很大，故易漏诊，或误认为翻出的膀胱是生殖器。
　　泄殖腔外翻的特征性表现为下腹壁缺损和下腹壁软组织包块、回肠脱垂、无膀胱、耻骨分离和生殖器畸形。
greenfeildwrote:
Abdominal-WallDefects腹壁缺损

Chapter58BladderExstrophy膀胱外翻
Chapter59Body-StalkAnomaly体蒂异常
Chapter60CloacalExstrophy泄殖腔外翻
Chapter61EctopiaCordis异位心
Chapter62Gastroschisis腹裂
Chapter63Omphalocele脐膨出
Chapter64PentalogyofCantrellCantrell五联症

膀胱外翻、体蒂异常、腹裂、脐膨出的内容不少。

泄殖腔外翻、异位心、Cantrell五联症没有找到密切相关的东西。
试着翻译了体蒂异常这一节，请版主修改
CHAPTER59Body-StalkAnomaly
CONDITION
Body-stalkanomalyisasevereabdominal-walldefectthatresultsfromabnormalitiesinthedevelopmentofthecephalic,caudal,andlateralembryonicbodyfolds.Thismaldevelopmentresultsintheabsenceorshorteningoftheumbilicalcordwiththeabdominalorganslyingoutsidetheabdominalcavityanddirectlyattachedtotheplacenta（Shalevetal.1995）.Body-stalkanomalywasfirstdescribedbyKermaunerin1906inanewbornwithanabdominal-walldefectconsistingofanamnioticsacthatcontainedviscera;theanteriorwallofthesacwasdirectlyattachedtotheplacentaandtherewasnoumbilicalcord.Otherthanthereferencesgivenintextbooksofpathology,body-stalkanomalywasnotappreciatedinthegeneralobstetricliteratureuntilthereportofLockwoodandcolleaguesin1986.
Aftergastrulation,theembryoconsistsofathree-layered,flat,ovalgerminaldisk.Therapidgrowthoftheembryo,especiallyalongthesagittalaxiscausesthegerminaldisktocurve.Throughcircumferentialfolding,theembryobecomescylindrical.Asaresultofthisprocess,thebodyoftheembryocloses,thebodystalkforms,andanintraembryoniccoelom（peritonealcavity）separatesfromanextraembryoniccoelom（chorioniccavity）（Giacoia1992）.Theamnioticcavity,whichisinitiallylocateddorsaltothegerminaldisk,growsrapidlyandeventuallyencirclesthefetus,obliteratesthechorioniccavity,andenvelopstheumbilicalcord.Theabnormalityinthefoldingprocesspreventsthisobliterationofthechorioniccavityandformationoftheumbilicalcord.Withoutanumbilicalcord,thefetusbecomesdirectlyattachedtotheplacentalchorionicplate.Thisbody-stalkanomalyconsistsofasacofamnionCmesodermthatcontainsthedisplacedabdominalorgans（Giacoia1992）.
Causesproposedforbody-stalkdefectincludeearlyamnionrupturewithdirectmechanicalpressureandamnioticbands（seeChapter101）,vasculardisruptionoftheearlyembryo,oranabnormalityinthegerminaldiskthatleadstotheformationofananomalousamnioticcavity.Intheearly-amnion-rupturetheory,theabdominal-wallandspinaldefectscouldbesecondarytothepassageofthelowerhalfofthefetalbodyintothecoelomiccavitythroughthedefectintheamnioticsac.Thefetushasnoroomtomoveandremainspracticallyattachedtotheplacenta.Limbamputationsandencephalocelecouldbesecondarytotheentrapmentofthefetalskulland/orlimbsinthecoelomiccavity（Daskalakisetal.1997）.Alternatively,earlygeneralizedcompromiseofembryonicbloodflowcouldleadtoafailureofclosureoftheventralbodywallandpersistenceofthecoelomiccavity（VanAllenetal.1987）.Thiscouldalsoleadtoaruptureofanunsupportedamnionandformationofamnioticbands.
体蒂异常是一种严重的腹壁缺陷，是由于胚胎头襞、尾襞及两侧襞的发育异常引起的。这种发育异常导致脐带过短或缺失，以致于内脏器官膨出于腹腔，甚至直接与胎盘相连。体蒂异常由Kermauner1906年首次报道，他描述一个的新生儿腹壁缺损，代之以包裹内脏器官的羊膜囊，腹前壁直接与胎盘相连，没有脐带。体蒂异常仅在病理学教科书上提及，在普通产科学中一直未被重视，直到1986年Lockwood及其同事提出这一问题。
原胚肠形成后，胚胎由一个三层的扁椭圆形胚盘形成。胚胎的迅速发育，尤其是延失状轴，使胚盘卷曲。通过圆周形折叠，胚胎变成圆柱形。这一过程，使胚体关闭，体蒂形成。内胚腔（腹膜腔）与外胚腔（绒膜腔）分离。最开始位于胚盘背侧的羊膜腔迅速生长，最终包绕胎儿，使绒毛膜封闭并包裹脐带。如果这一包卷过程发生异常，就会阻碍绒膜腔封闭及脐带形成。没有脐带，胎儿就直接与胎盘绒毛膜板相连。这种异常的体蒂由羊膜―－中胚层腔组成，其中包含了移位的腹部器官。
体蒂缺陷的原因包括机械压力致早期的羊膜破裂、羊膜蒂（见图101）、早期胚胎血管破裂及胚盘异常引起的羊膜腔形成异常。在早期羊膜破裂理论中，腹壁和脊柱缺失可能继发于胚体下半部分通过羊膜缺陷进入体腔。胎儿没有活动空间，因而事实上直接附着于胎盘。截肢和脑膨出可能继发于胎儿头骨和（或）肢体在体腔中卡压。无论何者，早期胚胎广泛血流损害，导致了腹壁关闭不全，体腔存留。这也会导致无支架的羊膜破裂并形成羊膜带。
PentalogyofCantrellisanunusualformofabdominal-walldefectthatconsistsoffiveassociatedanomalies,including:（1）midlineepigastricabdominalwalldefect,（2）defectofthelowersternum,（3）deficiencyoftheanteriordiaphragm,（4）defectinthediaphragmaticpericardium,and（5）intracardiacdefects.ThisconstellationofanomalieswasfirstdescribedbyCantrelletal.（1958）,hence,thetermpentalogyofCantrell,althoughithasalsobeenreferredtoastheCantrell-Haller-Ravitchsyndromeandperitonealpericardialdiaphragmatichernia.AlthoughpentralogyofCantrellhasbeenusedinterchangeablywithectopiacordis,intheiroriginaldescriptionCantrelletal.（1958）werecarefultodistinguishbetweenthesetwoanomalies.
Cantrell五联症是罕见的腹壁缺损形式，由5个异常构成，包括：（1）腹壁中线缺损，（2）胸骨下段缺损，（3）前膈肌缺损，（4）膈肌心包缺损，及（5）心内缺损。Cantrell等1958年首次描述这个异常组合。因此，Cantrell五联症，也被称为Cantrell-Haller-Ravitch综合征和腹膜心包膈疝。虽然Cantrell五联症曾经与异位心互换使用，在1958年Cantrell等原始的叙述中仍被细分为两种畸形。


简单谈谈对腹裂的治疗

腹裂的发生率大约为存活新生儿的1/30000。大多表现为脐右侧的前腹壁缺损,肠管疝出腹腔。随着产前超声检查的普及和技术的提高,通常能在产前获得诊断,超声显示邻近脐部的扩张肠管游离于羊水中。尽管选择性提前分娩理论上可以减少羊水对肠道的刺激,但并没有证据显示提早剖腹产会改善预后。自然阴道分娩对大多数腹裂患儿是合理的选择,除非脱出肠管异常膨大。

由于腹外、腹内组织间液的丢失,腹裂新生儿第一个24小时的液体需要量是普通新生儿的2～3倍,平均液体需要量大约为175ml/（kg•d）,一般来说,暴露的肠管表面越粗糙,炎症越严重,复苏所需要的液体量就越大。约50%的腹裂患儿不可能行一期肠管回纳、腹壁修复,勉强关闭腹壁可引起横膈抬高、通气受限而影响心肺功能,也会引起腔静脉受压导致回心血量减少,过高腹压可导致腹腔内脏器缺血性损伤及呼吸衰竭。1967年Schuster首先应用人工材料作为储袋临时关闭腹腔,使这类患儿获得了更多的生存机会。在各种合成材料和生物材料中,应用最广并被广泛接受的仍是医用硅胶制成的储袋。硅胶材料柔软、透明、刺激小,肠管在袋内易于被观察,并可通过袋内液体色泽判断有无继发感染和穿孔,用手可直接按压袋壁判断袋内压力,临床较为安全、实用。1995年Fischer等报道了应用改良Silo袋――在硅胶袋袋口放置弹簧圈,使储袋放置更为方便,无需缝合,使并发症更少、生存率更高。以后陆续有多篇相关类似的报道,并有提出无需进手术室,于ICU床边直接放置Silo袋的报告。传统的Silo技术,由于储袋基底需与腹壁缺损缝合、牵拉,可导致缝合处组织炎性水肿,甚至撕裂,为二期关闭腹壁、脐部整形带来不便。吴晔明等于2004年首先将免缝Silo技术在国内作了报道,并于2005年报道了在非麻