Andersons pediatric cardiology 251

univentricularpalliationafterbirth.(C–D)Thispatienthadatechnically
successfulprocedureandabiventricularoutcome.LV,Leftventricle.
(ModifiedfromFreudLR,McElhinneyDB,MarshallAC,etal.Fetalaortic
valvuloplastyforevolvinghypoplasticleftheartsyndrome:postnatal
outcomesofthefirst100patients.Circulation.2014;130[8]:641.)

ComparedwithpatientsmanagedasHLHS,freedomfromcardiacdeathwas
betteramongpatientswithabiventricularcirculationatmidtermfollow-up(Fig.
10.7).However,biventricularpatientshadsubstantialcardiacmorbidity,often
owingtoresidualASorborderlineleftheartstructures.Nearlyallpatients
requiredpostnatalcardiaccatheterizationand/orsurgery.Valvereplacements
wereamongthemostcommonproceduresperformed,and18%ofpatients
requiredbothaorticandmitralvalvereplacementsatmidtermfollow-up.
Resectionofendocardialfibroelastosiswasalsoperformedatthetimeofcardiac
surgeryforotherindicationsin86%ofpatients.34Notsurprisingly,inadditionto
theborderlinesizeoftheleftheartstructures,diastolicdysfunctionand
pathologicLVremodelingmaycomplicatepostnatalmanagement.35,36The
borderlineleftheartstructuresanddiastolicdysfunctionresultedin
approximatelyone-thirdofthispopulationdemonstratingpulmonary
hypertension,typicallyinthemildrange,atlatestfollow-up.29

FIG.10.7 Kaplan-Meiercurvedepictingcardiacmortalitybetween
hypoplasticleftheartsyndrome(HLHS)andbiventricular(BV)outcome
groupsbasedontheinitialpostnatalmanagementstrategy.(Modifiedfrom


FreudLR,McElhinneyDB,MarshallAC,etal.Fetalaorticvalvuloplastyfor
evolvinghypoplasticleftheartsyndrome:postnataloutcomesofthefirst
100patients.Circulation.2014;130[8]:641.)

Aswithotherpatientswithborderlineleftventricles,thereisnoprecise

formulathatwilldictatemanagementintheneonatalperiod.However,because
theetiologiclesioninthissubgroupofpatientsappearstobetheaorticvalve,an
attemptatpostnatalaorticvalvuloplastyisreasonabletoconsiderifthereis
residualobstruction.Ifthereisconcernregardingthedevelopmentofsevere
aorticregurgitationthenasurgicalvalvotomymaybepreferred,dependingon
institutionalpreference.Subsequenthemodynamicswillprovidecriticaldataas
towhethertheLVmaysupportthesystemiccirculation.Iftheleftheartremains
inadequate,EmaniandcolleagueshavedemonstratedthatstagedLV
recruitment,involvingaorticandmitralvalvuloplasties,resectionofendocardial
fibroelastosis,andrestrictionoftheatrialseptum,maypreserveabiventricular
outcome.37,38Forpatientswhoproceeddownthesingleventriclepathwayearly
inlife,conversiontoabiventricularcirculationispossiblewithreasonable
outcomeiftheLVend-diastolicpressureisrelativelylow(<13mmHg).39,40
Postnatalmanagementofpatientsfollowingsuccessfulfetalaortic
valvuloplastyiscomplexandheterogeneous,whichisoftenduetodifferencesin
myocardialresponse.Althoughsomepatientsmayrequireonlyapostnatalaortic
valvuloplastytoachieveabiventricularcirculation,othersmayrequireinitial
stagedsingleventriclepalliationwithongoingLVrehabilitation.Long-term
follow-upofthispopulationandofpatientsmanagedasHLHSiscriticalto
assesswhichsuperiormanagementstrategyisbetterovertime.Whetheritis
preferabletohaveabiventricularcirculationwitharehabilitatedLVorto
proceedwithstagedreconstructionwithasystemicrightventricleremainstobe
seen.


PulmonaryAtresiaWithIntactVentricular
SeptumandEvolvingHypoplasticRight
HeartSyndrome(SeeAlsoChapter43)
Similartofetalaorticvalvuloplasty,therationaletoperformfetalpulmonary
valvuloplastyforPA/IVSandevolvingHRHSistoalterthenaturalhistoryand

permitabiventricularoutcomeafterbirth.Fetalpulmonaryvalvuloplasty
involvesperforatinganddilatingtheatreticpulmonaryvalvetofacilitateright
heartgrowththroughouttheremainderofgestation.However,PA/IVSisamore
heterogeneousdiseasethansevereASwithevolvingHLHS,andthewide
spectrumofmanagementandoutcomesisoftenbasedonthedegreeofright
ventricularandtricuspidvalvehypoplasia.41,42Forexample,fetuseswith
PA/IVSandseverelyhypoplasticrightventricles,whichmaybeassociatedwith
fibromuscularatresiaoftherightventricularoutflowand/orarightventricular–
dependentcoronarycirculation,arenotcandidatesforfetalcardiacintervention.
Asneonates,suchpatientstypicallyundergostagedreconstructionasinother
formsofafunctionallyuniventricularheart.Ontheotherendofthespectrumare
fetuseswithonlymildlyhypoplasticrightventriclesinwhompostnatal
pulmonaryvalvuloplastyaloneisoftensufficienttoachieveabiventricular
circulation.
Candidatesforfetalpulmonaryvalvuloplastyfallinthemiddleofthe
spectrumandwouldbeexpectedtobemanagedwithatleastonepalliative
procedureintheneonatalperiod.Suchpatientsareconsideredtohavean
intermediatecirculation,andwhetherabiventricularcirculationisultimately
achievedisdependentonpostnatalmanagementstrategy.43–45Ideally,fetal
cardiacinterventionwouldenablesuchpatientstoachieveabiventricular
circulationintheneonatalperiod.

PatientSelection
PA/IVSisdiagnosedinuterobythepresenceofpulmonaryatresiawithleft-torightflowthroughtheductusarteriosusandrightventricularhypertrophywith
elevatedrightventricularpressure,whichoftencanbeassessedquantitativelyby
thepresenceoftricuspidregurgitation.Thedegreeofrightventricular