Andersons pediatric cardiology 1265
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ClinicalFindings
Patientswithavascularringmaydevelopsymptomsandsignsofairway
obstructionand/oresophagealcompression.3–10Clinicalmanifestationsvary
withtheseverityofencroachmentonthetrachea,bronchus,oresophagusbythe
abnormalarteryorarteries.Theseverityofcompressionofthetracheaand
esophagusnotonlydependsonthetypeofanomalybutisalsoaffectedbythe
sizeandshapeofthethoraciccageenclosingthevascularstructuresandairway.
Forinstance,achestcagewithdiminishedanteroposteriordiameter,asinstove
chestorstraight-backsyndrome,isassociatedwithmoreseverecompression
thananormallyshapedchestcage.Inaddition,dilationofavascularcomponent
oftheanomalousaortaoritsneighboringvesselandhyperinflationofthelungs
mayfurthercompromisethepatencyoftheairwayandesophagus.
Tightervascularringsusuallypresentearlyinlifewithrespiratorysymptoms,
whereaspartialringsmaypresentlaterwithsymptomsofesophageal
compression.Patientswithadoubleaorticarchtendtohavetheearliestonsetof
symptoms.Commonpresentingsymptomsarerespiratory,includingstridor,
wheezing,andcough.Astudyofalargecohortshowedthatsymptomatic
patientshavesignificantlyalteredtrachealgeometry,withsmallerdiametersand
cross-sectionalareascomparedwithasymptomaticpatients.59Thecharacteristic
stridorisinspiratory,butitmaybebothinspiratoryandexpiratory.Stridormay
notbeobviousduringsleeporquietplayandisexacerbatedbyexertionor
crying.Theseverityandpatternofstridorornoisybreathingcanchangewith
position.Theremaybeahistoryofrecurrentrespiratoryinfectionsrequiring
medicalattention,andsomepatientshavebeenreferredforanevaluationof
suspectedasthmaorbronchiolitis.Infantswithatightvascularringmayshow
life-threateningreflexapneawithfeeding.Someinfantsshowopisthotonic
posture,withhyperextensionofthenecktorelievetrachealcompression.6
Respiratorysymptomsseenininfancyorearlychildhoodmaydisappearwith
conservativemedicaltreatmentasthethoraciccagebecomesmorespaciousas
thepatientgrows.60
Symptomsofesophagealcompression,includingdysphagiaorchoking,
usuallydeveloplaterwhenthepatientcommencestotakesolidfoods.
Dysphagiaisoftenthefirstsymptominolderpatients.16,23Thislateonsetof
dysphagiamayberelatedtotheelongationoftheaortaorbesecondaryto
aneurysmalchangesofanexistingdiverticulumofKommerellortheadjacent
descendingaorta.16,24,28Dysphagiamaybeassociatedwithfrequentaspiration.
Avascularringisoccasionallydiagnosedatthetimeofremovalofforeign
bodies,suchaschickenbonesandcoins.WhenadiverticulumofKommerell
developsaneurysmalchange,itmaybecomplicatedbydissectionandfrank
rupture.16,21,24,28
Themajorityofpatientswithisolatedabnormalitiesgrowadequately.
Uncommonly,theremaybefailuretothriveandpoorphysicaldevelopmentdue
tofrequentpulmonaryinfectionsand/ordifficultieswithfeeding.Rarely,the
patientmaypresentwiththesymptomsofcompressionofanerveplexusbyan
abnormallypositionedaortaoritsbranch.32Incidentaldiscoveryofananomaly
isnotuncommonfollowingimagingforothermedicalproblems.
DiagnosticInvestigations
Thechestradiographisasimpleandlogicalstartingpointfortheimaging
algorithm(Fig.47.15).Itprovidesinformationregardingnotonlythepositionof
theaorticarchbutalsothepulmonarycomplicationsoftheanomaly,ifpresent.
Thelateralityoftheaorticarchrelativetothetracheaisusuallyreadilyapparent.
Thetracheaisbenttotheothersideoftheaorticarch.Thetrachealaircolumn
usuallyshowsasubtleindentationcausedbytheaorticarch.Inmostcasesthe
positionofthearchcanbetracedbackfromthedescendingaorta,whichcanbe
identifiedasaverticallinearstripealongthebonyspinalcolumn.Whenthe
aorticarchandtheverticallinearstripeoftheproximaldescendingaortaare
seenontheoppositesides,adoubleaorticarch,oracircumflexretroesophageal
aorticarchwiththedescendingaortaontheotherside,shouldbesuspected.A
doubleaorticarchmaycauseaconcentricnarrowing,withbilateralindentation
inthelowertrachea,butmorefrequently,thenarrowingisasymmetricandthe
indentationisunilateral.Bilateralindentationbyothertypesofvascularringis
rare.Thelateralviewmayshowanteriorbowingofthedistaltracheawhenthere
isalargeretroesophagealcomponent(Fig.47.16).Adilatedproximalesophagus
containingairmaysuggestthepresenceofaretroesophagealcomponent.The
superiormediastinumiswidewhenthereisacervicalaorticarch,anda
mediastinalmasscanbemistakenlysuspected.However,thesuperior
mediastinuminyoungchildrenisnormallywidebecauseofalargethymus.
Atelectasisorpneumonicconsolidationinvolvingvariouslungregionsmaybe
presentandmasktheunderlyingmalformation.Insomecases,hyperinflationof
thelungsorpartsofthelungsmaybethepredominantradiographicfeature.
FIG.47.15 Frontalchestradiographsshowinganormalleftaorticarch
