Andersons pediatric cardiology 1763
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implantationinanapex-formingleftventricle.Patientswithsystemic
morphologicrightventriclespresentchallengesintheimplantationofthe
ventricularcannula,owingtothedifferentanatomyoftherightcomparedwith
theleftventricle(e.g.,musclebundles)andthefactthattherightventricledoes
notformanapex.Adjustmentsalsoneedtobemadetotheorientationofthe
pumpbecausethesystemicventriclemaybeanterior(D-transpositionofthe
greatarteries)ormoreposteriorandwithdextrorotation(L-transpositionofthe
greatarteries),andthegreatvesselssituateddifferentlythaninnormalanatomy.
Bothpulsatile85–89andCFpumpshavebeenusedforthisapplication.90,91Many
oftheseauthorsoffernuanceddescriptionsoftheimplantationtechniqueintheir
reports.
Untilrecently,mostpublicationsonMCSinACHDwereintheformofcase
reports,92–95singlecenterreviews,96,97andafewdatabaseanalyses,83,98allwith
averylimitednumberofpatients.Then,in2017,areviewofINTERMACSdata
identified126of16,182patientsreceivingMCSashavingACHD.99Thestudy
foundthatACHDpatientswithLVADshavesurvivalsimilartonon-ACHD
patients.Ofthosepatients,63hadsystemicmorphologicleftventricleand17
wereSVH.Overall,theACHDpatientswereyoungerandsignificantlymore
likelytoundergoimplantationasabridgetotransplant.BiVADandTAHwere
morecommoninACHDpatients(21%vs.7%),whichmayhavebeena
reflectionofthemmorecommonlybeingINTERMACSprofile1comparedwith
theirLVADcounterparts.Onceagain,BiVAD/TAHsupportwastheonly
variableindependentlyassociatedwithmortality(earlyphasehazardratioof
4.4).Surprisingly,singleventriclewasnotseentobeariskfactor,butasthe
authorsnoted,thismayhavebeenatypeIIerrorsecondarytosmallnumbers.In
linewithadultpractices,82%oftheACHDpatientsunderwentCFdevice
implantation.Notably,ventricularmorphologywasnotassociatedwithmortality.
ThisstudydemonstratedapromisingroleforVADsupportinACHD
populationswithgoodbridgetotransplantoutcomesandencouragedmore
timelyandfrequentVADsupportofACHDpatientsinsevereheartfailure.
PerioperativeManagement
TheperioperativemanagementofVADpatientscanbechallenging,andthere
areanumberofimportantconsiderations.PatientconditionatthetimeofVAD
implantiscriticallyimportant,andasmuchaspossiblethepatientcondition
shouldbeoptimized.However,asnotedpreviously,manychildrenarein
cardiogenicshockatthetimeofplacementofadurableVAD.Whetheraperiod
ofMCSwithECMOoratemporaryVADpriortoplacementofadurableVAD
improveslong-termoutcomesremainsanimportantoutstandingquestion.100–102
Intheimmediatepostoperativeperiod,controlofbleedingandtimingof
anticoagulationareimportantconsiderations.IntheBerlinHeartEXCORtrial,
majorbleedingwasreportedin40%to50%ofpatients.103Thisisimportant
becauseanticoagulationisneededtopreventembolicdiseaseincludingstroke,
whichisalsocommonintheearlypostoperativeperiod.Thestrokeratewas
nearly30%intheBerlinHeartEXCORtrial,withmosteventshappeninginthe
earlypostoperativeperiod.103,104Thishighlightstheneedforearlycontrolof
bleedingtoallowforsafeearlyinitiationofanticoagulationtherapy.Major
bleedingisalsocommonamongchildrensupportedwithCFVADs,althoughthe
incidenceofstrokeappearstobeless.105ItisnotclearthecontributionofVADspecificversuspatient-specificfactorsinthedevelopmentofneurologicand
otherpost-VADadverseevents.Thetypeofanticoagulationused,timingof
anticoagulationinitiation,andongoingsurveillanceandadjustmentof
anticoagulationvarygreatlyamongdifferentdevicesanddifferentcenters.106,107
Muchoftheearlymedicaltherapyisaimedatsupportingtherightventricle.
MostpatientsaresupportedwithaLVADalone,andintheabsenceofSVH
disease,areatriskforrightventricularfailureintheimmediatepostoperative
period.Althoughmostchildren,especiallythosewithDCM,canbesuccessfully
managedwithoutmechanicalrightventricularsupport,BiVADsupportis
occasionallyneeded.Unfortunately,therearenoclearcriteriathatidentify
patientsthatwouldbenefitfromaBiVADorTAH.108–110Inareviewofpatients
supportedwiththeBerlinHeartEXCORVAD,nofactorwasidentifiedthat
predictedaclinicalbenefitfromBiVADsupport,includingsmallpatientsize,
ECMO,andhighbilirubinlevels.110Thisisnottosuggestthatrightventricular
failuredoesnothappenintheimmediatepostoperativeperiodorthatitisnot
associatedwithmajormorbidity.However,itcanbesuccessfullymanaged
medicallywiththeearlyuseofpulmonaryvasodilatorssuchasinhalednitric
oxideforafterloadreduction,inotropicsupport(e.g.,milrinone,dopamine,
epinephrine),andoptimizingpulmonarymechanicswithastrategyofearly
extubation.Overall,biventricularsupportwiththeuseofaBiVADorTAH
occursinlessthan20%ofpatients.4
TherearemanyotherpotentialcomplicationsofVADsinchildren,andmajor
adverseeventsarerelativelycommoninchildrenasinadults.16,111Overall,the
freedomfromanymajoradverseeventsofdevicemalfunction,infection,major
bleeding,orneurologicdysfunctionislessthan25%by6monthsafterVAD
placement.105Someoftheseadverseeventsarehigherinparacorporealpulsatile
flowdevicesascomparedwithintracorporealCFdevices,althoughthe
contributionofdeviceversuspatientsfactorstotheseadverseeventsneeds
furtherstudy.16,105Mostofthecomplicationscanbemanagedanddonotleadto
permanentdisabilityordeath,andmanyofthesepatientsaresuccessfully
supportedontheirVADtotransplant.16,104,112
Aftertheimmediaterecoveryperiod,muchattentionispaidtoongoing
rehabilitation,maximizingnutrition,andreducingmorbiditiesassociatedwith
prolongedintensivecareunitandhospitalcare,includinghospital-acquired
infections.Asnotedpreviously,manypatientsgototheoperatingroomforVAD
placementwithmultiorgansystemdysfunction,andimprovingthisstateis
crucialforasuccessfulVADoutcome,whichformostchildrenisheart
transplantation.PatientsonVADsupportwhogointohearttransplantationwith
severemultiorgansystemdysfunctionhaveahospitalmortalityofnearly20%
comparedwithonly2%amongVAD-supportedpatientswhohavenoorgan
dysfunctionatthetimeoftransplant.13Thishasledtopracticeofmanycenters
todelayactivelistingforhearttransplantationuntilthepatienthasrecovered
wellandisfreefromorgandysfunctionafterVADplacement.11,113
OutpatientManagement
IncreaseduseofintracorporealVADsinpediatricheartfailurepatientshas
allowedfordischargetohome.Successfultransitiontotheoutpatientsetting
requiresasignificantamountofeffortandmobilizationofresourcesfroma
rangeofprovidersinvolvedinthepatient'sday-to-daycare.ApediatricVAD
programincludesprovidersacrossmultipledisciplineswithadditionaltraining
indevicemanagement.Ateamisgenerallyamultidisciplinaryteamof
specialistswhoinmostinstanceshaveundergoneadditionaldevicetraining,
