Andersons pediatric cardiology 1845

patency,theductisligated.Themainpulmonaryarterycanbebandedwitha
varietyofmaterialincludingePTFE,polyestertape,orsilk.Theaortais
separatedfromthepulmonaryarteryandthetapepassedaroundthemain
pulmonaryartery.ThelengthofbandcanbeestimatedaccordingtotheTrusler
rule.Thelengthofthebandshouldbe20mmplusthenumberofmillimeters
correspondingtothechild'sweightinkilograms.77Neonateswithtransposition
physiologywillbemorecyanoticduetounfavorablestreaming.Inthiscasethe
lengthshouldbe24mmplusthechild'sweighttopreventexcessive
hypoxemia.77Arterialsaturationandpressureinthedistalpulmonaryartery
shouldbemonitoredduringbanding.ThepatientshouldbeplacedonanFiO2of
50%todecreasetheamountofdissolvedoxygen.Thebandshouldbeadjusted
toachieveadistalpulmonaryarterypressureof15to20mmHgorone-fourthof
thesystolicbloodpressure.Thesaturationshouldbe80%to85%.Acommon
techniqueistousehemoclipstomakethefinaladjustments.Thisallowsthe
bandtobetightenedandloosenedin1-mmincrements.Thefinaladjustmentis
commonlyacompromisebetweenachievingasatisfactorypressureandavoiding
excessivehypoxemia.Oncethepropertightnessisachieved,thebandissecured
withmultiplesuturesbetweenthebandandthepulmonaryartery.Ideallythe
bandshouldbeabovethesinotubularjunctionofthepulmonaryvalveandnot
impingingontheoriginofeitherpulmonaryartery.Ifitisnotproperlysecured,
thebandcanslipandcompromisetheoriginofapulmonaryartery,typicallythe
rightpulmonaryartery,andresultinexcessivehypoxemia.Ifthebandis
positionedtoofarproximally,itcanencroachonthepulmonaryvalveandresult
inleafletdamage,whichcancauseregurgitation.

RestrictedorDuct-DependentSystemicBlood
Flow
Obstructiontosystemicflowcanoccurduetoarchhypoplasiawithcoarctation,
aorticvalvestenosis,subaorticstenosis,oracombinationoftheselesions.These
newbornswillbemaintainedonprostaglandintomaintainsystemicoutput.
Creationofunobstructedsystemicoutflowisimportanttomaintaincardiac

outputandpreventhypertrophyoftheventricle,whichwouldcompromisefuture
palliation.PatientswithfUVHandobstructedsystemicbloodflowwillalsohave
unobstructedpulmonarybloodflow,andreliefofsystemicoutflowobstruction
mustbecombinedwithrestrictionofpulmonarybloodflow.


DecisionMaking.
Forisolatedcoarctationwithorwithoutarchhypoplasiaandwithoutadditional
leftventricularoutflowtractobstruction(aorticvalvarorsubaorticstenosis),
standardcoarctationrepaircanbeperformed(seealsoChapter45).Ifthearch
hypoplasiaisdistaltotheoriginoftheleftcarotidartery,thearchcanbe
approachedviaaleftthoracotomy.Ifthereisproximalarchhypoplasia,an
approachviaamediansternotomyusingcardiopulmonarybypasswillbe
necessary.78Theprocedurecanbecombinedwithpulmonaryarterybanding.
IncertaingroupsoffUVHswithadominantleftventricleanddiscordant
ventriculoarterialconnections,theaortacanarisefromarudimentaryoutflow
chamberorrightventricleandconnecttotheleftventricleviaaninterventricular
communication.Arestrictiveinterventricularcommunicationwillresultin
systemicoutflowtractobstruction.Whentheinterventricularcommunicationis
smallatbirth,aortichypoplasia—frequentlywithcoarctationandoccasionally
withaninterruptedaorticarch—maybepresent.Evenwhentheinterventricular
communicationisnonrestrictiveatbirth,itcanbecomenarrowovertime,
resultinginobstruction,andthetendencyforsystemicoutflowobstructionto
progressafterpulmonaryarterybandinghasbeenwellrecognized.79,80
Strategiestopreventdevelopmentofoutflowtractobstructionormanageits
presenceincludeananastomosisbetweenthepulmonaryrootandtheascending
aorta—theDamus-Kaye-Stansel(DKS)proceduresimultaneouslydescribedby
PaulDamus,MichaelKaye,andHoraceStanselinthe1970s(Fig.71.4).81–85
Theanastomosisofthepulmonaryrootandaortabypassestherestrictive
interventricularcommunication.Adirectapproachatenlargementofthe

interventricularcommunicationischallengingintheneonateandrisksinjuryto
theconductionsystemwithresultantcompleteheartblock.86


FIG.71.4 ExamplesoftheDamus-Kaye-Stansel(DKS)procedureforthe
reliefofsystemicoutflowobstructioninthesettingofadominantleft
ventriclewithtransposedgreatvesselsandtheaorta(Ao)arisingfromthe
rudimentaryrightventricle(rv,RV).(A)DiagramshowingaDKSfor
tricuspidatresiawithtransposition.(B)DKSinapatientwithdouble-inlet
leftventriclewithL-loopedventricles.LV,Leftventricle;PA,pulmonary
artery;PT,Pulmonarytrunk.(A,FromYooSJ,CaldaroneCA.Glossaryof
paediatriccardiovascularsurgicalprocedures.In:YooSJ,BabynP,
MacDonaldC,eds.ChestRadiographicInterpretationinPediatricCardiac
Patients.NewYork:Thieme;2010:41–54.B,FromGatesRN,LaksH,
ElamiA,etal.Damus-Stansel-Kayeprocedure:currentindicationsand
results.AnnThoracSurg.1993;56:111–119.)

ADKSprocedurerequirescardiopulmonarybypass;thereforecoarctation
repairwithpulmonaryarterybandingoffersthenewbornalessmorbid
procedure.Inthecurrentera,whereabidirectionalsuperiorcavopulmonary
anastomosisisgenerallyperformedduringinfancy,aninterventricular
communicationareagreaterthan1to2cm2/m2(correspondingtoa
interventricularcommunicationdiameterof7mmorgreater)isareasonable
cutoffidentifyingthosepatientswhoareunlikelytodevelopobstructionduring
infancypriortoasuperiorcavopulmonaryanastomosis.Inthesepatients,arch
repairandpulmonaryarterybandingcanbeconsideredforneonatalpalliation
andamoredefinitiveproceduretopreventsystemicventricularoutflow
obstructioncanbepartofthesecond-stagepalliation.87,88
Moresevereformsofsystemicventricularoutflowtractobstructionare
frequentlyassociatedwithcoarctationandarchhypoplasia.Thisincludesmore

severeformsoffUVHwithadominantleftventricleanddiscordant
ventriculoarterialconnection(tricuspidatresiawithtransposedgreatvessels),
andthosewithdominantrightventricleandconcordantventriculoarterial