Andersons pediatric cardiology 989
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pattern(Fig.37.20)wasalmosttwicethatseeninpatientswiththeusualpattern.
Inthisreview,asingleoriginofthecoronaryarteriesandintramuralpatterns
wereassociatedwithdeath.Anotherrecentstudyalsoreportedhigherriskfor
adversepostoperativeoutcomesinpatientswithabnormalcoronaryarterial
anatomy.84Becauseechocardiographyisnotabletodelineatetheircoursewith
absolutecertainty,itisincumbentuponthesurgeontoconsiderthepossibilityof
atypicalcoronaryarterybranchingpatternsinanypatientandtobepreparedto
managethemastheyarise(Video37.6).
FIG.37.20 Intraoperativeimagedemonstratingananomalyofthe
coronaryarteries.Therightcoronaryartery(RCA)andleftanterior
interventricularartery(LAI)canbeseentoshareacommonorigin.The
rightcoronaryarterysweepsanteriortothearterialpedicle.
SurgeryforComplexTransposition
TranspositionWithaVentricularSeptalDefect
Thepresenceofaventricularseptaldefectwaspreviouslyanimportantrisk
factorforincreasedsurgicalmortality,althoughthisislesssointhecurrentera.
InareviewofEuropeancenters,themortalityforthearterialswitchinthe
presenceofaventricularseptaldefectwasfoundtobe13%,comparedwith3%
whentheventricularseptumwasintact.Thepresenceofadefectwasfoundto
besignificantonunivariatebutnotonmultivariateanalysis.66Inareviewofthe
experienceinMichigan,65itwasobservedthatthepresenceofaventricular
septaldefectdidnotaffecttheoutcomeforthearterialswitchoperation,whereas
themostrecentdatafromthedatabaseofTheSocietyofThoracicSurgeons
CongenitalHeartSurgeryreporta2.7%mortalityforarterialswitchalone
comparedwith5.3%whenthereisconcomitantrepairofaventricularseptal
defect.63
SurgeryinInfantsWithSignificantPulmonary
Hypertension
Persistentpulmonaryhypertensionresultsfromafailureofthenormalpostnatal
reductioninpulmonaryvascularresistance.Intransposition,thiswillresultin
ongoinghypoxemiainthepresenceofseeminglyadequatecommunicationsat
theatrialandductallevelsandnoanatomicobstructiontoQP.20Inhalednitric
oxidemaybebeneficial,althoughithasbeendemonstratedthatperioperative
mortalitymaybeincreased.85Pulmonaryvasculardiseasecanalsodevelop
rapidlyinthepresenceofaventricularseptaldefect,orwhenanarterialductis
sufficientlylargetocausepulmonaryhypertension.Whenpulmonaryvascular
diseaseisestablished,patientsmaynolongerbecandidatesforcorrective
surgery.Asaguide,apulmonaryvascularresistanceofgreaterthan8Wood
unitsisconsideredtoindicateunsuitability.Medicalmanagementwithinhaled
nitricoxide,prostaglandin,pulmonaryvasodilators,orevenextracorporeal
membraneoxygenationcanbeusedinanattempttoimprovesurgicalcandidacy.
Anatrialredirectionprocedure,leavingtheinterventricularcommunication
open,theso-calledpalliativeatrialredirection,willimprovestreamingand
improvesystemicoxygenationinpatientswhocannotundergoanarterialswitch.
Thereasonforleavingtheinterventricularcommunicationopenisbasedonthe
premisethatitwillactasaroutefordecompressionoftheleftventricleifthe
pulmonaryvascularresistancesuddenlyrises.Applyingthesameprinciples,a
palliativearterialswitchhasbeenused.86Giventheprogressivenatureofthe
pulmonaryvasculardisease,morbidityandmortalityremainhigh.
TranspositionWithCoarctationorInterruptionof
theAorta
Obstructionoftheaorticarchisrarewhentheventricularseptumisintact.Itis
morecommoninthosewithaventricularseptaldefect,particularlywhenitis
associatedwithanteriordeviationoftheoutletseptum.Thusthedetectionof
hypoplasia,interruption,orcoarctationoftheaortashouldalertthecardiologist
toexamineevenmorecarefullytherightventricularoutflowtract,thesizeofthe
rightventricle,andthetricuspidvalve.Iftherightventricleortricuspidvalveis
small,aconventionalrepairmaynotbeappropriate.Itisgenerallyacceptedthat
asingle-stageoperationshouldbeperformedforrepairoftransposition
associatedwithobstructionoftheaorticarch.Althoughnotthefirsttodescribe
thisasasingleoperation,Planchéandcoworkerswerethefirsttodemonstrate
thesuperiorityofthisoverastagedapproach.87,88Thesurgicaltechniqueforthe
aorticanastomosisdoesnotrequiresignificantmodificationbecausethe
LeComptemaneuvergenerallyallowsadirectrepairofthecoarctationwith
minimaltensionontheanastomosis,althoughaugmentationwithapatchmay
occasionallyberequired.89Ananalysisofthearterialswitchprocedurein
Europeancentersdidnotdemonstrateincreasedmortalityratesforpatientswith
anabnormalityoftheaorticarch,66althoughmanypatientsmayneed
reintervention(catheter-basedorsurgical)forrecurrentobstruction.90
SurgicalOptionsinthePresenceofObstruction
totheLeftVentricularOutflowTract
Obstructiontoleftventricularoutflow,orpulmonaryobstruction,ismost
commonlyassociatedwithaventricularseptaldefect.Theneedforminor
outflowtractresectionatthetimeofthearterialswitchdoesnotnecessarily
contraindicatethisoperation.Wheretheobstructionissevereorcomplex,itmay
beappropriatetoconsideranalternativeprocedure.AEuropeanmulticenter
reviewfoundthattheRastelliprocedure(discussedlater)wasthemost
commonlyusedtechniqueinthesecircumstances.91Asagroup,mortalitywas
higherinpatientswhohadtheirsurgeryearlierinthetimeframeofthestudy,
thoserequiringalongerdurationofcardiopulmonarybypasstime,andthose
whoseseptaldefectswerenotcommittedtoeithertheaortaorpulmonaryartery.
At1,10,and20yearsaftersurgery,survivalrateswere88%,88%,and58%,
respectively.
RastelliProcedure.
