Andersons pediatric cardiology 1468

FIG.55.11 DifferentinflationstagesoftheInoueballooninpercutaneous
mitralballoonvalvuloplasty.(CourtesyMagdiYacoubFoundation,Aswan
HeartCenter.)

Thedouble-balloontechniquewasintroducedafewyearsaftertheInoue
techniqueandinvolvescrossingthevalvewithtwowiresoverwhichtworegular
balloonsareadvancedacrossthevalve.68Thistechniquehastheadvantageof
beingcheaper—animportantfactortoconsiderinresource-poorsettings—and
enablestheuseofasmallervascularaccess,whichmightbeadvantageousin
smallpatientsandcanresultinslightlylargervalvearea.However,this
techniqueismoretime-consuming,moretechnicallychallenging,andcarriesan
increasedriskofLVperforationcomparedwiththeInouetechnique.The
multitracksystemutilizesthesameconceptasthatofthedouble-balloon
techniquebutwithacombinationofover-the-wireandrapidexchangeof
balloons,enablingtheuseofasingleguidewireandhencesimplifyingthe
procedure.69
Themetallicvalvutome,inspiredbythesurgicalTubbsdilator,wasintroduced
in1995.70Itconsistsofametallicdilatormadeofstainlesssteelscrewedonto
thedistalendofacatheter.Thedistalhalfofthedilatorconsistsoftwo
hemicylindricbarsthatcanbeopenedoutinparallelbyalever-armsystem.The
openingofthesetwobarsleadstoseparationofthecommissures.This
innovationmightbeveryappealingfromacostperspective,astheentiresystem


issterilizable;however,limitedoutcomedataandcomplexityhavelimitedits
widespreadadoption.Table55.3summarizesthekeyfeaturesofthesevarious
techniques.
Table55.3
ComparisonofDifferentPercutaneousMitralValvuloplasty
Techniques

DoubleBalloon

MultitrackSystem

1985

2004

Non–
BalloonBased
Metallic
Valvutome
1995

++

+

+

+++
(+)perforation

++
(+)perforation

+++
(+)
perforation

Technicallyeasierthandouble
balloon(onlyonewireneeded)

Resterilizable

$$$

$

Balloon-Based
InoueBalloon
Year
1982
introduced
Use
+++
(penetrance)
Complexity
++
Complications
Mortality:
0%–3%
Tamponade:
0%–4%
Embolism:
0%–3%
SevereMR:
1%–4.6%
Failure:1%–
15%

Advantages
Lowerriskof
LV
perforation
Relatively
easy
Cost
$$$$

Slightlylargervalve
areacomparedto
Inoue
Smallersheath
required
$$

MR,Mitralregurgitation.

ComplicationsandOutcomes
Themaincomplicationsofthepercutaneousapproacharecardiactamponade,
severeMR,systemicembolism,andfailuretoachieveanacceptableMVarea
(definedas>1cm2/m2bodysurfacearea)(seeTable55.3).Themid-andlongtermoutcomesofPMBVhavebeenevaluatedinanumberofstudiesshowing
favorableresultscomparedwithclosedandopencommissurotomy.Event-free
survival(aliveandwithoutMVreplacement,repair,orredoPMBV)ratesat10


yearsvaryfrom56%to90%indifferentseries,withpatientswithWilkins
scoresatorbelow8havingsignificantlybetteroutcomes.Olderage,previous
surgicalcommissurotomy,severityofMRbeforeandaftertheprocedure,and
highpulmonaryarterypressureareadditionalindependentpredictorsofadverse

outcomes.71

PercutaneousManagementofAorticStenosis
Significantrheumaticaorticstenosisisrareinyoungpatients.Thereare
thereforeverylimiteddataonpercutaneousaorticballoonvalvuloplastyin
youngpatientswithrheumaticaorticstenosis.Althoughaorticballoon
valvuloplastymayhaveanimportantroleintreatinginfantsandchildrenwith
severecongenitalaorticstenosis,thisisprobablylimitedtocriticallyillpatients,
orasabridgetoopenheartsurgeryinthosewithrheumaticaorticstenosis.