Andersons pediatric cardiology 875

FIG.33.12 Echocardiographicimagesshowingtomogramstakeninan
apicalfour-chamberplaneofanormalheart(left)andaheartwithEbstein
malformation(right).Thehingepointofthenormalseptaltricuspidleafletis
positionedslightlytowardthecardiacapexrelativetotheseptalhingepoint
oftheanteriormitralleaflet(outlinedbythearrowsatleft).This
displacementisexaggeratedinheartswithEbsteinmalformation,asshown
atright.Thiscanbequantitatedbythedisplacementindex,dividingthe
distancebetweentheseptalvalvarinsertionsbythebodysurfacearea.A
valueofgreaterthan8mm/m2isdiagnosticofEbsteinmalformation.It
shouldbenotedthatthevalvarleafletsarealsoabnormalinEbstein
malformation.Inthecaseillustrated,theleafletsarethickenedand
moderatelydysplastic.LA,Leftatrium;LV,leftventricle;RA,rightatrium;
RV,rightventricle.

Otherechocardiographicfeaturescanaidinmakingthediagnosis,including
elongationoftheanterosuperiorleaflet,tetheringofleafletstotheunderlying
myocardium,shortenedchordalsupport,attachmentoftheleadingedgeofthe
anterosuperiorleaflettotherightventricularmyocardium,displacementofthe
annularattachmentoftheinferior(andlessoftentheanterosuperior)leaflet,
absenceoftheseptalorinferiorleaflets,congenitalfenestrationoftheleaflets,
andenlargementofthevalvarannulus.
Completeechocardiographicassessmentshouldincludeacompletesegmental
examination,withspecialattentiontodefinitionofthetricuspidvalveapparatus,
anddescriptionofthefunctionalstatus/sizeoftherightventricle,thepulmonary
valve/arteries,andtheatrialseptum.Valvarassessmentsfocusonthesizeand
mobilityofeachleaflet,thedegreeofleafletadherencetotheRVmyocardium,
andthefunctionalimpact(regurgitationorobstruction)resultingfromthese
anatomicdeformities.Thisinformationiscriticaltothedecision-makingprocess
andthetimingofsurgicalinterventions.
Overthepastdecade,the“cone”repairhasbeenfoundtobeaveryeffective
approachtotricuspidvalvereconstructioninpatientswithEbsteinmalformation

andinsomeserieshasbeensuccessfullyappliedtomorethan90%ofpatients.
Previous“monoleaflet”repairsweresuccessfulinmuchasmallerpercentageof
patientsandreliedprimarilyonanteriorleafletmobilityto“coapt”withthe
ventricularseptum.Incontrast,theconereconstructionusesallavailableleaflet
tissue,includingtissuesurgicallydelaminatedatthetimeoftherepair.This
allowscreationofacircumferentialconeofleaflettissuesurroundingthe
effectivevalveorifice.Thistechniquealsorelocatestheannularhingepointto
theleveloftheatrioventriculargrooveandreliesonchordalsupportfromthe
rightventricularapex.Asaresult,thepresence/sizeofamobileseptalleaflet,
whichprovidesananchortothecylindricalvalvereconstruction,hastakenon
greaterimportanceintheprerepairassessment.
Traditionally,themostimportantdeterminantofadurablemonoleafletrepair
wasafreelymobileanterosuperiorleaflet,especiallyitsleadingedge.The
presenceofsuchamobileleafletremainsafavorablefinding,simplifyingthe
conereconstructionbecauseless“surgicaldelamination”willberequiredin
thesecases(Fig.33.13).Extensiveadherenceoftheanterosuperiorleaflettothe
ventricularmyocardium(Fig.33.14)madeamonleafletrepairimpossible.
However,aconereconstructionmaystillbepossible,albeitmorechallenging,in
thesepatients(Fig.33.15,Videos33.1to33.4).Asinglecentraljetof
regurgitationismoreeasilyeliminatedthanaremultipleregurgitantorifices
usinganytechnique(seeFig.33.11).Evenwhenthereisasignificantamountof
leaflettissuepresent,directmuscularinsertionsfromtheventricularfreewall
intothebodyoftheanterosuperiorleafletcanmakeanyrepairmoredifficult
(Fig.33.16).Otherimportantfeaturesrequiringpreoperativedefinitioninclude
thedegreeofdysfunctionanddilationoftheanatomicrightventricle,the
presenceandsizeofanyatrialseptaldefect,andtheperformanceofthe
functionaltricuspidvalveleaflets(degreeofregurgitation/stenosis).29,48,49

FIG.33.13 Apicalfour-chamberinflowimagesofapatientwithEbstein
malformation.Theleftframeisfrommid-diastole.Themiddleandright
framesarefrommid-andend-systole,respectively.Featuresthatsuggest
favorableanatomyformonoleafletrepairarethattheanteriorleafletinthis
patientisfreelymobile,includingitsleadingedge(arrows).Thereareno
muscularinsertionsthatlimitordistortthemotionofthevalve.The
regurgitantjetoriginatedonlyfromthegapincoaptationseenbetweenthe
anteriorleafletandtheremnantoftheseptalleaflet.Theleadingedgeof
thevalvereachesapointnearenoughtotheseptumthat,giventhedegree
ofannulardilation,anannuloplastycanadvanceittoapointwhereitwill
coaptwiththeseptumandthevestigesoftheseptalleaflet.LA,Leftatrium;
LV,leftventricle;RA,rightatrium;RV,rightventricle.(ModifiedfromCetta
F,EdwardsWD,SewardJB,etal,Congenitalheartdisease.In:Vannan
MA,LangRM,RakowskiH,TajikAJ,eds.AtlasofEchocardiography.
Philadelphia:CurrentMedicineLLC;2005.)

FIG.33.14 Anatomicspecimen(left)andechocardiographicfour-chamber
image(right)demonstratingextremelysevereexamplesofEbstein
malformation.Noremnantsoftheseptalleafletarepresentwithintheinlet.
Eventheanteriorleafletshavefailedtofullydelaminateinthesehearts,