Andersons pediatric cardiology 987
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transposition,aspartofthe“doubleswitch”procedure(seeChapter38).
MustardandSenningProcedures
Theseproceduresinvolveremovaloftheatrialseptumandredirectionofthe
systemicvenouspathwaystothesubpulmonaryleftventricleandofthe
pulmonaryvenousbloodtothesystemicrightventricle.IntheSenning
operation,thisredirectionofsystemicvenousbloodisachievedbymeansofan
infoldingoftheatrialwalls,whereasintheMustardoperationthisisachieved
usingsyntheticorpericardialtissue.Oneofthemostpopularmodificationsof
theMustardoperationinvolvedcreationofatrouser-shapedbaffle,withthelegs
anastomosedtothesuperiorandinferiorcavalvenousinflows.57Bythe1980s,
suchatrialredirectionprocedureswereassociatedwithearlypostoperativerates
ofsurvivalexceeding95%.58
ArterialSwitchOperation
Animportantimpedimenttotheearlysuccessofanatomiccorrectionwasthe
requirementtorelocatethecoronaryarteries.Theadventofcoronaryarterial
bypasssurgeryinadultsinthelate1960sandthedevelopmentofmicrovascular
techniquessetthestageforcoronaryarterialtranslocationand,inturn,anatomic
correctionfortheinfantwithtransposition.Thefirstsuccessfularterialswitch
operationwasreportedbyJateneandcolleaguesin1975,52inanolderinfant
withanassociatedventricularseptaldefect.Despiteinitialincreasesinmortality
relatedtothisprocedurecomparedwithatrialredirection,59othersaroundthe
worldquicklyfollowedsuit,suchthatbytheearly1990sthearterialswitch
supplantedtheatrialswitchasthefavoredprocedureinmostinstitutions.During
thefirstdecadeofanatomiccorrection,thepioneersofthearterialswitch
undertooktheoperationininfantswithassociatedventricularseptaldefects,
whichweregenerallybeyondtheearlyneonatalperiod.Thefirstreportof
successfulcorrectionofaneonatewithanintactventricularseptumappearedin
1984.60
Itrapidlybecameclearthatanimportantdeterminantofearlyoutcomewas
theconditionoftheleftventriclepriortosurgery,whichdetermineditsabilityto
supportthesystemiccirculationafterwards.Hencetheintroductionoftwo-stage
repairforpatientswitha“deconditioned”leftventricle,withbandingofthe
pulmonarytrunkand,ifrequired,placementofasystemic-to-pulmonaryarterial
shunt.Thesefirst-stageprocedures“trained”theleftventricle,inpreparationfor
asubsequentarterialswitchoperation.61Thisapproachisstillusedinthe
treatmentofthepatientwhopresentslate(discussedlater).
Anotherimportantmodificationtothearterialswitchwasintroducedin1981.
NowwidelyreferredtoastheLeComptemaneuver,thisinvolvestheforward
loopingofthebifurcationofthepulmonaryarteriesoverthedividedaorta,
leavingtheneoaortalyingposteriorly(Fig.37.17,Video37.4).Followingthis
maneuver,thepulmonarytrunkitselfispositionedanteriorly,allowingits
anastomosiswiththeoriginalaorticrootwithoutcreatinganatomicdistortion.62
Thisprocedureisstillincorporatedbymostsurgeonsperformingthearterial
switchoperation.
FIG.37.17 AnteriorviewofthecompletedLeComptemaneuverusing
computedtomographyscanwithvolumerenderingtechnique.The
pulmonaryarteriesarebroughtanteriortotheaortatominimizedistortion.
LPA,Leftpulmonaryartery;RPA,rightpulmonaryartery.
Theprocedureascurrentlyperformedinvolvesthetransectionoftheaortaand
thepulmonarytrunk.Thecoronaryarteriesarethendetachedfromtheaorta,
alongwitha1-to2-mmcuffor“button”ofaortictissueandtransferredtothe
proximalendofthedividedpulmonarytrunk,thusformingthenewaorticroot,
ortheneoaorta.Extremecareshouldbetakentoavoidtension,torsion,or
angulationoftherelocatedcoronaryarteriesbecausepropertranslocationis
knowntobethemostcrucialfactorforasuccessfuloutcome.Thedefectsinthe
originalaorticrootleftsubsequenttodetachmentofthecoronaryarteriesare
repairedwithpericardium.TheLeComptemaneuverisperformed.Thedistal
endofthedividedaortaisthenanastomosedtotheneoaorta,therebyconnecting
themorphologicallyleftventricletothesystemiccirculation.Theanastomosisof
thepulmonaryarterytotheneopulmonaryvalvecompletestheprocedure(Fig.
37.18;Video37.5).
FIG.37.18 Typicalpostoperativeappearanceasseenbythesurgeon
aftercompletionofthearterialswitchoperation.
Thearterialswitchiscurrentlytheprocedureofchoiceforalmostall
neonates.Inthecurrentera,theoverallmortalityisverylow,withanoperative
mortalityrateof2.7%inpatientswithanintactinterventricularseptumand5.3%
