Andersons pediatric cardiology 1847

requiresplacementofanadditionalarterialcannulatosupplyflowtothe
descendingthoracicandabdominalaortaduringarchreconstruction.Thesiteof
distalcannulationcanincludecannulationofthearterialduct,descending
thoracicaortaatthelevelofthediaphragm,orfemoralartery.
Duringaperiodofaorticcross-clampingandalteredperfusion,arch
reconstructionincludingamalgamationoftheaorticandpulmonaryrootsis
accomplished(Fig.71.7).99Anonrestrictiveatrialseptaldefectiscreated.The
crossclampisreleasedandrewarmingcompleted.Finallyasourceofpulmonary
bloodflowisestablished—eitherasystemic-to-pulmonaryarteryshuntoraright
ventricle-to-pulmonaryarteryconduit.Oncerewarminghasbeencompletedand
cardiacfunctionhasreturned,vasoactivesupportisinitiated.Commonly
milrinoneandcatecholaminesareused.Priortoweaningfrombypass,the
patientshouldbeinanAVsequentialrhythm,hematocritshouldbeatleast35%,
ionizedcalciumshouldbewithinthenormalrange,andthesystemicvascular
resistanceshouldbeabout12Woodsunits.TheSVRcanbeestimatedby
dividingthemeanarterialpressurebythecardiacindex.Furtheradjustmentsof
vasoactiveagentsaremadetoachievethetargetSVR.Forthepatientwitha
systemic-to-pulmonaryarteryshunt,theshuntisopenedasthecardiopulmonary
bypassflowisreduced.Aftersuccessfulweaningfrombypass,modified
ultrafiltrationcanbeperformed.Evaluationoftheprocedureisthenundertaken.
Thiscanincludeechocardiography,eitherepicardialortransesophageal,to
evaluatefunction,theadequacyoftheatrialseptaldefect,andthedegreeof
tricuspidvalveregurgitation.RegionalperfusionasassessedbyNIRSshouldbe
usedtoassessDO2.100Residualsystemicoutflowobstructioncanberuledout
bycomparingthesystemicventricularsystolicpressurewithapressure
measuredfromthefemoralorumbilicalarterycatheter.Oncetheclinicianis
satisfiedwiththerepair,thevenouscannulaisremovedandprotamineis
administeredtoreverseanticoagulation.Thearterialcannulacanbeleftinplace
untilafterprotaminehasbeenadministered.Itisessentialtoachievecomplete
hemostasis.Transfusionofplateletsandfibrinogen—eitherfreshfrozenplasma
orcryoprecipitate—iscommon.Carefulinspectionofthesurgicalsitesshouldbe

undertakenandadditionalsuturesplacedasnecessary.Forcontinuedbleeding
thatdoesnotseemtobesurgicalandhasnotrespondedtocomponent
transfusion,additionalagentssuchrecombinantfactorVIIaorprothrombin
complexconcentratescanbeconsidered.


FIG.71.7 TechniqueofNorwoodarchreconstruction.(A)Aftercoolingon
cardiopulmonarybypassto18°C,cardioplegicarrestisachievedand
antegradecerebralperfusionestablished.Theaorticisthmusisdivided,
andalltheductaltissueisresected(inset).Theextentofresectionof
ductaltissueisdeterminedbyidentifyingthechangeinthicknessofthe
vessel,astheductusisslightlythicker-walledthantheaorta.Inaddition,
theintercostalvesselsarisefromtheaortaandtheductaltissueendsafew
millimetersawayfromthefirstsetofintercostalvessels.(B)After
mobilizingthedescendingthoracicaorta,whichrequiresdivisionofthefirst
twoorthreesetsofintercostalvessels,anincisionismadeintheaorta
fromtheopenendoftheaorticisthmustothelevelofthepulmonaryroot.A
cutbackismadeintheposterioraspectofthedescendingthoracicaorta.
Thecutbackincisionisdirectedtowardtheoriginoftheintercostalvessels.
(C)Aninterdigitatingarchreconstructioniscreated.Thedescending
thoracicaortaisadvancedasfarasthedistalascendingaorta.Alarge
suturelinefromnativetissuetonativetissueiscreated.Apatchofporcine
smallintestinalsubmucosaisfashionedasaquartercirclewitharadiusof
3.5cm(inset).Thepatchisusedtoaugmentthearchandascendingaorta
andcompletetheconnectionoftheaortaandpulmonaryroot.Thepatchis
alignedbeginningatthewhitearrow.Thestraightedge,indicatedbythe
blackarrow,issuturedtotheinnercurvature,andthecurvededge,
indicatedbythegrayarrow,issuturedtotheoutercurvature.Theaortic
rootisjoinedtothepulmonaryrootinanincisioninthepulmonaryrootjust
leftwardofthecommissureadjacenttotheascendingaorta.(D)Thepatch

isbeingsewnintoplace.(E)Excesspatchistrimmed(notshown)andthe
proximalsuturelinecompleted.(FromJacobsenRM,MitchellME,Woods
RK,etal.Porcinesmallintestinalsubmucosamaybeasuitablematerial


forNorwoodArchreconstruction.AnnThoracSurg.2018;106[6]:1847–
1852.)

Oncehemostasishasbeenachieved,thedecisiontocloseversusleavingthe
sternumopenismade.Forthosepatientswhohavehadalongbypassrunand
areonmorethantheusualinotropicsupport,delayedsternalclosuremaybe
necessary.Althoughsomeprogramsroutinelyleavethesternumopen,thereis
littlequestionthatthisprolongsthelengthoftimetoextubationand,asa
consequence,alsoCICUlengthofstayandhospitalization.Thereforeitseems
reasonabletodeterminewhetherthesternumcanbeclosedprimarily.Sternal
closuresuturesareplacedandthesternumreapproximated.Thehemodynamics
areevaluatedandifthereisnoperturbation,sternalclosurecanbecompleted
andtheremainderoftheincisionclosedintheusualmanner.Ifsternal
approximationresultsinimportanthypotensionand/ordesaturationorifthereis
evidenceofdecreasedsystemicDO2asassessedbyNIRSorvenoussaturation,
thesternumshouldbeleftopen.Oncethepatientbeginstodiureseand
vasoactivesupportcanbeweaned,chestclosurecanbeperformed.Ifthepatient
failstoprogress,residuallesionsshouldberuledout.
Thehybridapproachisdefinedbyplacementofindividualbranchpulmonary
arterybands.45Ductalpatencyismaintainedwitheitherastentorprostaglandin.
Inaddition,catheter-basedcreationofanonrestrictiveatrialseptaldefectis
necessaryifthisisnotalreadypresent.Typicallytheprocedureisperformedina
hybridcatheterizationlaboratory.Amediansternotomyisperformed.Branch
pulmonaryarterybandingisperformedfirst.Rings2to3mmindiameterarecut
fromanePTFEtubegraftthatis3.0or3.5mmindiameter.Withthetypical

hypoplasticleftheartsyndromeanatomy,theleftpulmonaryarteryisbanded
first,asitisthemostdifficulttoaccess.45,101Therightpulmonaryarteryis
bandednext.Theadequacyofthebandingcanbedirectlymeasuredbycatheter
andadditionalfineadjustmentscanbemade.Ifastentistobeplacedto
maintainductpatency,thisisperformedlast.Theatrialseptaldefectcanthenbe
enlargedusingcatheter-basedtechniques.

NeonateWithUnobstructedSystemicBlood
FlowandPulmonaryStenosis:Balanced
Circulation
Finally,someneonateswithafUVHarebornwithwithouttheneedforneonatal