Andersons pediatric cardiology 1929

high.Improvementsintransplantstrategyandearlierreferralhaveimproved
results.Usingthedonorbranchpulmonaryarteriesgreatlyfacilitatesthe
transplantation.Becauseinfectioncausesthemajorityofearlydeathsinthese
patients,lower-intensityimmunosuppressioniswarranted.AttheLurie
Children'sHospital,transplantationwassuccessfulintreatingPLEinall
survivors.The5-yearsurvivalintheearlyportionofthatseries(1990to2011,n
=18)was60%.394Since2012(n=20)the5-yearsurvivalhasbeen95%.Avery
smallnumberoffailingFontanpatientsmaybenefitfromaventricularassist
device,andmostrecentlytherehasbeensuccessreportedwiththeSynCardia
device(SynCardiacSystems),animplantedtotalartificialheart.Thiscontinues
tobeanareaofinvestigationinselectedcenters.

FIG.73.29 Kaplan-Meiersurvivalcurveoffreedomofdeathand
transplantationintheearlyconversioncenterversustheothercenters.
(FromPohCL,CochraneA,GalatiJC,etal.Ten-yearoutcomesofFontan
conversioninAustraliaandNewZealanddemonstratethesuperiorityofa
strategyofearlyconversion.EurJCardiothoracSurg.2016;49[2]:530–
535.)

Managementofthepatientwitha“failingFontan”requiresamultidisciplinary
evaluationbypediatriccardiologists,pediatriccardiovascularsurgeons,
electrophysiologists,interventionalcardiologists,andtransplantsurgeons.
Optimizingoutcomesisdependentonearlyreferralforappropriatetherapyat
centerswiththerequireddepthofinstitutionalexperiencetomanagethese
complexpatients.

TimingofHeartTransplantation


Ingeneralterms,referralforhearttransplantationshouldoccuratatimewhen
expectedsurvivalwithtransplantexceedsthatwithoutatransplant.SomeFontan

failurepatientscanremainstablewithmedicaltherapyforyearswithout
transplantation,whereassomeexperienceaprecipitousdeclinethatisoften
difficulttopredict.Thusthereisafinelinebetweenbeing“toowell”and“too
sick”fortransplantationthatcanbeelusiveintheFontanpatient.Risk
assessmentfortransplantationismuchbetterunderstoodinpatientswithnormal
cardiacanatomyandtwoventriclescomparedwiththosewithafunctionally
univentricularheartalongtheFontanpathway.Itfollowsthatthecriteriafor
listingforhearttransplantationareprimarilybasedontheriskprofilesthatare
moretypicalforpatientswithtwoventricleswithdiminishedventricular
function.Listingcriteriavaryfromcountrytocountryandaretypicallymore
stringentinadultpatientswithvariableprovisionsforexceptionallistingstatus.
Thesecriteriatypicallyinvolveobjectivemeasuresofcardiacfunction,exercise
capacity,hemodynamicinstability,needforinotropicsupport,orneedfor
mechanicalsupport,withsickerpatientsreceivingpriorityfororganallocation.
TheselistingcriteriaareparticularlyillsuitedforadultFontanpatients,
particularlyasevidencedbysignificantlylongerwait-listtimesandhigher
perioperativemortality.394,399,400Survivalaftertheperioperativeperiodandafter
thefirstyearfollowingtransplantisbetterinpatientswithCHD,butthereareno
specificlong-termdataforthosewithapreviousFontancirculation.400
GiventhehighprevalenceofcirrhosisandotherformsofFontan-associated
liverdiseaseinthesepatients(seeearlier),itisimportanttodeterminewhether
thereisaneedforcombinedheart-livertransplantation,whichhasahigher
perioperativeriskandisperformedfarlessfrequentlythanhearttransplant.Most
patientswhorequirecombinedheartandlivertransplantationhavesystemic
diseasesuchasamyloidosis,familialhypercholesterolemia,orironoverload
syndromes(hemochromatosisandthalassemia),andthereisfarlessexperience
inthepatientwithafailingFontan.401,402
Practicesvary,andthereisnoagreeduponwayofdeterminingtheneedfor
livertransplantationinconjunctionwithhearttransplantationinpatientswitha
failingFontan.Althoughliverbiopsyisthegoldstandard,itssensitivityis

variable,anditmaybeoflimitedutilitybecauseofthepatchyand
heterogeneousnatureoffibrosis—withdenserfibrosisinthehepatic
periphery.403,404Thismayexplainlackofcorrelationwithclinicaloutcomesin
theFontanpopulation.
Innon-Fontanpatients,theMELDscoreisavalidatedandwidelyusedrisk


calculatorthatisusedforassessingprognosisandlistingpriorityforcirrhotic
patientslistedforlivertransplantation.MELDscorecalculationusesserum
creatinine,bilirubin,INR,andserumsodium,thelatterbeingaddedin2016.The
PediatricEnd-stageLiverDisease(PELD)scoreisasimilartoMELDandis
usedforpediatricpatientsyoungerthan12yearsofage.ThePELDscoreuses
albumin,bilirubin,INR,age,gender,height,andweight.PLEisassociatedwith
lowerbilirubinduetogastrointestinallossofproteinsthatincludealbuminboundbilirubin,sothesepatientswillhavelowerMELDandPELDscores.In
addition,theuseofvitaminKantagonistscanelevatetheINRandincrease
MELDandPELDscores.LiverimagingwithMRI,CT,ultrasoundand,more
recently,transientelastographycanhelptoquantifyfibrosis.This,inconjunction
withclinicalfeaturesofdecreasedrenalperfusionandportalhypertension,such
asproteinuria,varices,ascites,splenomegaly,andthrombocytopenia,canbeof
prognosticvalueandcanhelptodeterminewhetherlivertransplantationis
warrantedinconjunctionwithhearttransplantation.
ImprovingtheassessmentofprognosisinthefailingFontanisofcritical
importancewhenconsideringwhetherornottoreferfortransplantation.The
MELD-XIscoreisamodificationoftheMELDscorethatexcludesINRand
sodiuminthecalculation.154HigherMELD-XIscorespredictdeathor
transplantation,butthisscoretendstobeasurrogatemarkerfordecreasedrenal
functionbecauseitismostlydrivenbyelevatedcreatinine.
Renalresistiveindexisamarkerofrenalperfusionandisincreasedwith
elevatedCVP,widepulsepressure,hypoxia,heartfailure,liverdysfunction,and
diureticuse.AreportdemonstratedincreasedmortalityintheFontanpatient

withrenalresistiveindexof0.81orgreater.405
OthershavereportedahighVASscore(onepointeachforvarices,ascites,
andsplenomegalybyimaging)inadditiontocyanosisortheneedforpacemaker
tobeassociatedwithahigherincidenceofdeathorneedfortransplant.406An
importantobservationwasthataVASscoreof0wasassociatedwithaverylow
10-yeareventrate,whichcouldhelpidentifyagroupofpatientswhowouldnot
benefitfromtransplantation.
Althoughtheserisksscoresordiagnosticmethodsmaybeusefultoolsfor
serialmonitoringofthefailingFontanpatient,nonehasbeenvalidated
prospectivelyasameansofdeterminingprognosisortimingoftransplantation
referral.Furtherstudyisneededtohelpidentifypatientswithafunctionally
univentricularheartFontanwhoareathighestriskof12-to24-monthmortality.
Identifyingthesepatientsmayhelptorefinespecificandappropriatetransplant