Andersons pediatric cardiology 1186
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1.69%/patient-yearinamixedpediatricpopulation.134,143Freedomfrom
pulmonaryhomograftreplacementsaftertheRossprocedureis90%at12-year
follow-up,142witharightventricularoutflowtractdeteriorationrateof
1.66%/patient-year.134Overall,theriskofreoperationisapproximately10%at
10years,eitherontheautograftortherightventricularconduit.142Inyoung
adultpatients,theoverallsurvivalandfreedomfromreinterventionwerenot
significantlydifferentfollowingtheRossprocedurecomparedwithmechanical
valvereplacementatmeanfollow-upof14years.144
Aortic–LeftVentricularTunnel
IntroductionandAnatomy
Thisveryrarecongenitalheartdiseaserepresentsanabnormalconnection
betweentheascendingaortaandtheleftventricle.Thetunneloriginatesinthe
aorta,inmostcasesjustabovetherightcoronaryarteryintherightcoronary
sinusofValsalva.Thetunnelcoursesdownalongthebaseoftheaorticvalve
towardtheleftventricleandenterstheleftventricleimmediatelybelowtheright
coronaryleafletoftheaorticvalve.Rarelythetunnelmayarisefromtheleft
coronarysinusorendintherightventricleorleftatrium.Atunnelbypassingthe
valvecancompromisethestructuralsupportoftherightcoronarysinusand
resultinaorticregurgitation.Aneurysmaldilatationoftheintracardiactunnelcan
causesubpulmonaryobstructionbydisplacingtheinfundibularseptum
anteriorly.Rarelythecoronaryarterycanarisefromwithinthetunnel.
Externally,abulgeintheareaofaorticrootandtherightventricular
infundibulumcanbeseen.Twoanatomictypeshavebeendescribed:eithera
slitlikeopeningwithnoaorticdistortionorlargeovalopeningattheaorticend
withorwithoutaorticvalvedistortionpredisposingtodevelopmentof
intracardiacand/orextracardiacaneurysm.145
Pathophysiology,ClinicalFeatures,and
Investigations
Halfofthepatientspresentinearlyinfancywithcongestiveheartfailurecaused
byseverevolumeloadtotheleftventricle.Associatedlesionssuchasaortic
stenosis,aorticatresia,rightventricularoutflowtractobstruction,andventricular
septaldefectarerarebutcanmodifytheclinicalpresentation.146
Theelectrocardiogramdemonstratesleftventricularhypertrophy,withor
withoutrepolarizationabnormalitiesduetoleftventricularstrainorischemia.
EchocardiogramandDopplerflowstudiesarehighlyreliableinestimating
morphology,flowinthetunnel,andfunctionalandmorphometricparametersof
theleftventricle(Fig.44.22).Thepresenceofparavalvarregurgitationrendersit
difficulttoevaluatethestatusofnativeaorticvalvebyechocardiogram.
Additionalanatomicimagingwithmagneticresonanceimaging,computed
tomography,orcatheterizationcanbeuseful,inparticularwithidentifyingthe
coronaryostiainrelationshiptothetunnel.
FIG.44.22 Transthoracicechocardiographicimagesfromaparasternal
longandshortaxisshowanaortic–leftventriculartunnel(arrow).Notethe
aorticregurgitationarisingabovethevalvarleaflets.AO,Aorta;LV,left
ventricle;T,tunnel.
Management
Aortic–leftventriculartunnelsareprimarilyaddressedsurgically.Symptomatic
neonatesandinfantsundergosurgicalrepaironanurgentorsemiurgentbasis
