Bonegroup2012.6.7HistoryMale,62yearsoldAtransientsyncopeSphygmus:72times/min,left--weakBloodpressure:rightarm—110/70mmHgleftarm—70/50mmHgPossiblediagnosis?Why?FinaldiagnosisImageimpression:Subclavianarterywallcalcification,stenosis;thrombosiscannotbeexcludedClinicaldiagnosis:SubclavianStealSyndrome(SSS)SubclavianStealSyndromeDefinition:Subclavianstealsyndromeistheproximalsubclavianarteryorinnominatearteryobstruction(causedbyavarietyofreasons),Subclavianarterydistalintraluminalpressuredecreased,ipsilateralbloodpressurebelowthevertebral–basilararterialpressure---syphonage,soresultinSSSClinicalmanifestationsupperlimbsymptom:Somepatientscomplainedofweakness,numbnessandpainwhentheupperlimbsexerciseVertebrobasilarinsuficiencysymptom:Syncope,dizziness,vertigo,standinginstabilityandoccipitalpainisthemostcommoncomplaintcarotidarteryinsufficiencysymptom:rarely,butcanoccurinthepatientofinnominatearteryobstructionPhysicalfindingsIpsilateralradialarterypulseweakenedordisappeared,bilateralpulsenonsynchronization(delay0.03~0.06s)Pressuredifferential(PD)>20mmHg(contralateral>Ipsilateral)(Only16%ofthepatientswithaPD20mmHgdidnothaveSSS.ThisresultsuggeststhatarmBPdifferential20mmHgishighlycorrelatedwiththepresenceofSSS)PhysicalfindingsTheipsilateralsupraclavicularfossavascularbruit(systolic)Javidtest:positive(aftertheoppressionofthecommoncarotidartery,radialarterypulseweakened)PathogenyArteriosclerosis(mostcommon)Congenitalmalformations(aorticstenosis,subclavianarterydistalatresia)Takayasuarteritis(tuberculosis,syphiliticaortitis)TumorcompressionRadiotherapySSSbloodpathway(一)VA-VAcontralateralvertebralartery↓vertebrobasilararteryconfluence↓ipsilateralvertebralartery↓ipsilateralsubclavianarterydistalSSSbloodpathway(二)BA-VAbasilarartery↓ipsilateralvertebralartery↓ipsilateralsubclavianarterydistalSSSbloodpathway(三)PCA-BA-VAposteriorcerebralartery↓basilarartery↓ipsilateralvertebralartery↓ipsilateralsubclavianarterydistalSSSbloodpathway(四)OA-VAexternalcarotidarterybranchoccipitalartery↓occipitalarteryandvertebralarteryanastomoticbranch↓vertebralartery↓subclavianarterydistalDiagnosticmethods(一)Dopplerultrasoundexamination※Observethebloodflow※VertebralarteryappearingreversespectrumisthetypicalperformanceofSSSA,Normalflowinapatientwithoutsubclavianstealsyndrome(SSS).Ithasalowwavepatternresistancewithcephaladflowthroughoutthecardiaccycle.B,FlowvelocitywaveformintheleftvertebralarteryindicatingapartialSSS.Theflowduringsystoleandthebeginningofdiastoleisreversed.Therewasa25mmHgPD.C,CompletestealinapatientwitharmbloodPDof60mmHg.Theflowinthevertebralarteryisreversedthroughoutthecardiaccycle.TheseveritycanbegradedbasedonthevertebralDopplerspectralpatterns:I:antegradeflowwithdiminishedpeaksystolicvelocityII:alternatingflow—antegradeflowinthediastolicphaseandretrogradeflowinthesystolicphaseIII:completelyretrogradeflowDiagnosticmethods(二)DigitalSubtractionAngiography—DSA※DSA---thegoldstandardstodiagnoseSSSthedegreeofSubclavianarterystenosisthelocationofsubclavinaarterytheprogressoftherefluxbloodflow(thecontralateralvertebralartery→theipsilateralvertebralartery→theipsilateralsubclavianarterydistal)※limitionexpensive,invasive,difficulttorepeatsensitivetocompletedstenosis,bu...