Andersons pediatric cardiology 1861

thethoracicductandcarrylymphtowardthecentralvenoussysteminthe
thorax.Lymphaticfluidcontains,fats,lymphocytes,immunoglobin,and
coagulationfactors.Anyelevationofcentralvenouspressure,asoccursasa
predictableconsequenceoffUVHpalliation,canproducerelativeobstructionto
thenormaldrainageoflymphaticfluidintothecentralvenoussystemandresult
inachylothorax.Althoughelevationofcentralvenouspressureisananticipated
consequenceofsurgicalpalliationandearlychylousdrainageiscommon,this
generallyresolvesafteradayortwofollowingSCPCpalliation.
Thetermschylothoraxandchylouseffusiongenerallyrefertoeffusionsor
highoutputfromachesttubethatpersistsformorethanaweek.Thefirststepin
managementistoruleoutanyanatomicabnormalitiesthatcanraisecentral
venouspressure,suchasobstructionofthesuperiorcavopulmonarypathway,
thrombusinthesuperiorvenacava,oradditionalsourcesofpulmonaryblood
flow.Directinjurytothethoracicductcanalsoresultinchylothorax,whichcan
resultinchylothoraxinthesettingofanoptimalanatomicresultandfavorable
hemodynamics.Iftherearenoanatomicissues,astepwisetreatmentplanis
begunthatstartswithalow-fatdiettolimitlymphproduction.Thiscanbe
escalatedtoNPOandTPN.Additionalmedicaltherapiescanbeadded,
includingoctreotide,steroids,andaldactone.237Forrecalcitranteffusions,
thoracicductligationandpleurodesiscanbeconsidered.
Inadditiontotakingstepstolimitthedrainage,treatmentmustalsobe
directedatthepathophysiologyofongoinglossofchylousfluid.Ongoingchest
tubedrainagecanresultinmalnutritionduetolossofproteinsandfat,
developmentofhypercoagulabilityduetolossofcoagulationfactors,and
immunocompromiseduetolossoflymphocytesandimmunoglobin.Patients
withprolongedeffusionsareatriskforthesecomplications.Thesecomplications
candevelopinsidiouslyandexacerbatetheclinicalcourse.Forexample,lossof
coagulationfactorscanresultinline-relatedthrombosisofacentralline,which
canfurtherelevatecentralvenouspressureandleadtoevengreaterhydraulic
stimulustotheformationofachylouseffusion.Ongoingoralintakewillresult
inincreasedchylousoutputandparadoxicallyworsenproteinloss.Makingthe

patientNPOandbeginningTPNwilllimitongoingproteinlosswhilesupporting
nutrition.Replacementofchesttubeoutputwithfreshfrozenplasmawilllimit
thedevelopmentofcoagulopathy.Anticoagulationwithunfractionatedheparin
orlow-molecular-weightheparinmaylimitthromboticcomplications.


FamilySupportandInterstageIISurveillance
andMonitoringAftertheSuperior
CavopulmonaryConnection
Twoofthemostcommonstressorstofamiliesduringthesecondinterstage
period(interstageII)is(1)thelossofthecontinuityandavailabilityofthe
interstagemonitoringteam(seeChapter72)and(2)thevariabilityinpractice
regardingtypeandfrequencyofdiagnosticstudiesandtimingoftheFontan
procedure.3,238TheSCPCphysiologyissignificantlymorestablethanthe
multidistributioncirculation,andtheemphasisofcareshiftsfromphysiologic
stabilitytoafocusongrowthanddevelopment.Thisisalsothetimewhenany
additionalsurgicalprocedures—eithercardiac(e.g.,valvuloplasty)ornoncardiac
(e.g.,gastrointestinal,orthopedic,urologic)—aretypicallyperformed.
Familysupportfrequentlyshiftsfromthededicatedinterstageteamtolocal
andInternet-basedsupportgroups.239–241Increasingnumbersofcentershave
startedlifelongprogramsspecificallyforpatientswithfUVHandtheir
families.242Additionally,familiesareincreasinglyparticipatinginresearchand
developingbest-practicemodelsalongwithclinicians.243–245


Third-StageReconstruction:The
ModifiedFontanProcedure
ThethirdstageofreconstructionandtheultimategoalforthepatientwithfUVH
isthemodifiedFontanprocedure.Patientswithtricuspidatresiaandnormally
relatedgreatvesselsweretheimpetusfordevelopingtheFontan

procedure.246,247Experimentalproceduresandearlyreconstructiveeffortswere
directedatbypassingtheobstructedrightside.248–254Successinpatientswith
tricuspidatresiawasfollowedbyapplicationofFontanpalliationtoawide
varietyoffUVHanatomies.HydrodynamicstudiesdeterminedthatasmoothcaliberunobstructedFontanpathway(ratherthanattemptingtoincorporatethe
pulsatilerightatriumasapumpingchamber)minimizedenergylossand
improvedoutput.255TheextracardiacFontansimplifiedtheprocedureeven
furtherandpermittedapplicationtoevenbroaderanatomicvariants.256The
modifiedFontanprocedurewillrelievecyanosisbyseparatingpulmonaryand
systemicvenousreturnandwillrestore,ascloselyaspossible,anormalin-series
bloodflowpattern(Box71.7).Allofthepreviousproceduresareaimedat
creatingthebestpossibleFontancandidate—onewithpreservedsystolicand
diastolicsingle-ventriclefunctionandwell-developedpulmonaryvasculature
withlowpulmonaryarteriolarresistance(seeChapter70).


Box71.7

GoalsoftheFontanProcedure
■Surgicalbafflingfromtheinferiorvenacavatothepulmonaryartery
■Minimization/eliminationofhypoxemia
■Performanceofadditionalprocedures(e.g.,pulmonaryarteryplasty,
septectomy,valvuloplasty)

PreoperativeEvaluation
Toassessriskandguidesurgicalplanning,thefactorsoutlinedinTable71.9