Andersons pediatric cardiology 991
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bedetachedandreimplantedtominimizerotationalorlongitudinaltension
duringtranslocation.ThemostintuitiveadvantageoftheNikaidohoverthe
REV,andparticularlytheRastellioperations,isthatsystemicoutflowisnot
directedthroughanintraventricularbaffle,andthereforetheprocedurecarriesa
lowerriskofobstructiondevelopinglaterwithintheleftventricularoutflow
tract.Resultsfromthisprocedurehavebeenpromising,91,96althoughmore
extendedfollow-upisneededtoassessitspotentialadvantagesoverother
procedures.
FIG.37.24 Nikaidohprocedure.Thisoperationisalsousedforcorrection
inpatientswithaventricularseptaldefectandobstructiontooutflowfrom
theleftventricle(LV)intothepulmonarytrunk.Theupperleftpanelshows
theoriginalsituation,withthedottedlinesshowingtheincisionsfordivision
ofthetransposedarterialtrunksandtheopeningtothesubaortic
infundibulum.Themiddlepaneloftheupperrowshowshowtheaorticroot
isliberatedfromtherightventricle,takingwithitthecoronaryarteries,and
anincisionmadethroughtheoutletseptumintothepulmonaryroot.The
rightpaneloftheupperrowthenshowshowtheanterioraspectofthe
pulmonaryrootisexcisedtowidentheoutflowfromtheleftventricle.The
leftpanelofthelowerrowshowshowtheaorticrootistranslocated
posteriorlyandsuturedintotheoutflowtractfromtheleftventricle,
attachingtheroottotheventricularseptumwithapatchsothattheleft
ventricleejectsintotheaorta.Theaortaitselfisthendivided.Themiddle
panelofthelowerrowshowshowtheseparatedpulmonaryarteriesare
translocatedbetweenthecomponentsofthedividedaorta,andthe
posterioraspectofthepulmonarytrunkisattachedtothesuperioraspect
ofthepatchusedtoclosetheventricularseptaldefect,theaortahaving
beenreanastomosedbehindthepulmonarytrunk.Therightpanelofthe
lowerrowshowshowtheprocedureisthencompletedbyuseofapatchto
reconstructtheoutflowtractfromtherightventricletothepulmonary
arteries.
Long-TermSurgicalOutcomes
AtrialRedirectionProcedures
Thelateoutcomesofatrialredirectionarewelldescribedbecausetheoperation
hasbeenperformedformorethanahalfcentury.Theyhavegenerallybeenvery
good,withsurvivalratesafter27yearsofgreaterthan90%,with90%of
survivorsnotrequiringreoperation.97Whenneeded,themainindicationsforlate
surgerywereobstructionofthevenousbaffles,failureofthesystemicright
ventricle,regurgitationofthetricuspidvalve,andacquiredobstructiontotheleft
ventricularoutflowtract(Fig.37.25).Inarecentstudyofmorethan400patients
whounderwentatrialswitch,therewasnosurvivalbenefitwhencomparing
MustardandSenningtechniques.98Theauthorssuggestthatsurvivalisprimarily
affectedbyabilityoftherightventricletofunctioninitsroleofsupportingthe
systemiccirculationandthatcliniciansshouldfocusonrightventricularand
tricuspidvalvefunctionasmarkersofwell-being.Obstructiontosystemic
venousreturncanusuallybemanagedwithtranscatheterangioplastyand/or
stenting,althoughsurgicalinterventionmayberequired.Analternativeoptionis
conversiontoanarterialswitch;however,carefulpatientselectionisadvised
becausethisstrategycarriessignificantrisk.99Bandingthepulmonaryartery,to
traintheleftventriclepriortoconversion,canitselfimproverightventricular
functionanddecreasetheseverityoftricuspidregurgitation.100Pacemakersare
sometimesusedforcardiacresynchronization.Althoughthecriteriafor
pacemakerinsertionareequivocal,mostwouldagreethatifapatientis
symptomatic,orifmonitoringrevealslongpauses,severebradycardia,or
tachyarrhythmiainthepresenceofbradycardia,thenapacemakerisjustified;
however,implantationmaybedifficultbecauseofthecomplexanatomy.Finally,
somepatientswillrequiretransplantation.
