主动脉瓣移植的临床展望课件

3/981ValveProsthesisMechanicaltypes:caged-ball,tilting-disk,bi-leafletadvantage:durabilitylimitation:thrombogenicityBioprosthetictypes:heterografts,homograftsadvantage:shorttermanticoagulationlimitation:structuralfailure3/982MechanicalValveProsthesisTypescaged-ball(Starr-Edwards)tilting-disk(Medtronic-Hall)bileaflet(StJude)Advantage:durability(1)Limitation:thrombogenicity1.NEnglJMed1996;335:407-4163/983BioprostheticHeterograftsadvantagelongtermanticoagulationunnecessary(1)limitation:structuralfailureleafletcalcification&tissuedegenerationleadingtovalvularregurgitationstenosisisuncommonrateofporcinevalvedegeneration

26%(aortic),39%(mitral)in10yrs(2)1.NEnglJMed1993;329:524-5292.AnnThoracSurg1990;49:370-3833/984BioprostheticHomografts1956-firstaorticvalvehomograftwasusedinthedescendingthoracicaortaforaorticregurgitation1962-firstsub-coronaryusehighincidenceofpost-opfailure*

(years) 5 10 15 20survivalrate(%) 85 66 53 38re-operation(%) 22 62 85 95*Circulation1991;84(suppl3):III81-III883/985BioprostheticHomograftsearlypreservationtechniquesformaldehyde,chlorhexidine,propiolactone,ethyleneoxide,

-irridiation,freezingat-70oCgraftsarenonviablehighincidenceofcusprupture3/986BioprostheticHomografts

advancesImprovingvalvedurabilitynewerpreservationtechniques:cryopreservationbyliquidnitrogenwithlow-doseantibioticshomovitalgrafts(freshunpreserved)reducedtimeforgraftprocurementdonorratherthanautopsyspecimens3/987BioprostheticHomografts

UniversityofAlabama1981-1991cryopreservedaorticgraftsin178ptssurvivalrate91%at1year85%at8yearsfreedomfromre-operation95%at8yearsJThoracCardiovascSurg1993;106:154-1653/988BioprostheticHomografts

PrinceCharlesHsopital1975-1994cryopreservedaorticgraftsin680ptshospitalmortality2.8%survivalrate77%at10year;45%at20yearsfreedomfromre-operation69%at15yearsO’Brian.AnnThoracSurg1996;60:S65-S703/989Homovitalhomografts

Londongraftsareharvested,storedintissueculturemedium,andusedin3days275graftsimplantedover13years:147subcoronary,128aorticrootnotransmissionofdiseasereportedcumulativesurvival85%at10yrs(94%intheaorticrootgp)freedomfromre-op:91%in10yrsJThoracCardiovascSurg1995;110:186-1933/9810BioprostheticHomografts

implantationtechniquesFreehandscallopedtechniqueretentionofminimaldonortissuetechnicallychallenging,requireexactsizingtopreventregurgitationCylindertechniqueretentionofnativeaorticsinusesandsinotubularjunctionrequirescoronaryreimplantationAnnThoracSurg1996;62:1069-10753/9811BioprostheticHomografts

implantationtechniquesMayoClinicseries1985-1994

implantation scalloped cylindernumbers 59 78latemod-sevAR 26% 12%7yrre-oprate 24.2% 11.5%AnnThoracSurg1996;62:1069-10753/9812BioprostheticHomografts

cylindertechniquesimprovedoutcomemaintainingthenaturalvalvegeometryandstructureensuresbetteraorticcuspcoaptationreducestheriskofaorticregurgitationAnnThoracSurg1996;62:1069-10753/9813The“Rossprocedure”Adoublevalveproceduretransferthepatient’snativepulmonaryvalveintotheaorticpositioninsertahomograftintotheresectedpulmonarypositionlongtermfollow-upof131pts47%survivalat20yrs(age11-52)35%re-op(15%aortic,10%pulmonary)Circulation1997;96:2206-22143/9814AorticValveHomograftcomplicationsaorticregurgitationisthemajormodeofgraftfailureearlyaorticregurgitation

technicalfactors(sizing,distortion)lateaorticregurgitation

commissuralmalalignment,cuspaldistortion,cuspalprolapsefromrootenlargementcuspaldeteriorationislesscommon3/9815AorticValveHomograftendocarditisLowincidenceofendocarditisaffectinghomografts:6%at15yrs(1)Treatmentofchoiceforprostheticvalveendocarditis(PVE)mortalityforPVEhasbeen20-50%hospitalmortalityreducedto8.3%withhomograftsinthetreatmentofPVE(2)1.AnnThoracSurg1995;60:S65-S702.SeminThoracCardiovascSurg1997;11:53-613/9816AorticValveHomograftanticoagulationMechanicalvalvesriskofthromboembolism,majorbleeding,strokeisapprox3%(1)withINRof2.5-4.9Aortichomograftsanticoagulationisunnecessary1.NEnglJMed1995;333:11-173/9817AorticValveHomograft

ConclusionAdvantageofnotneedinganticoagulationNotyetaperfectvalveAorticregurgitaitonstilloccurswithmodernpreservationtechniquesstructualfailurealsoalimitation,particularlyintheyoungpatient3/9818AorticValveHomograft

ConclusionInolderpatients(age>60),heterograftshavearelativelylowrateofstructuralfailure,theadvantageofhomograftsisminimalSurgicalexpertiserequired;maynotbeavailableatallinstitutions3/9819AorticValveHomograft

indicationsacti