Frequency and predictors for angiographically improved inflow of contrast medium after carotid angioplasty and stenting

Percutaneous transluminal carotid angioplasty and stenting (PTAS) can result in immediate improvement in cerebral blood flow (CBF) evident through faster transit of contrast medium on angiography. To evaluate frequency and predictors of changes in inflow of contrast medium before and after PTAS, we reviewed 86 patients (mean age 68.6 ± 9.1 years) treated for symptomatic or asymptomatic carotid stenosis. Clinical data and lesion characteristics were extracted from charts and digital angiograms, respectively. Perfusion change was assessed qualitatively by comparing pre- and poststenting images matched for projection and time from injection. Improved inflow was defined on the basis of spatial or temporal distribution of contrast medium: grade -1: fewer vessels visible after stenting; 0: no change; 1: more distal small arteries visible; 2: time-matched poststenting image showing a capillary blush; 3: time-matched poststenting image showing small veins, 4 time-matched poststenting image showing large veins and sinuses. Faster inflow of contrast medium was observed in 74% of patients (grades 1: 34%,and 4: 4.7%). In linear regression analysis, higher degrees of ipsilateral stenosis were associated with greater changes in inflow of contrast medium (P < 0.05). Right internal carotid lesions were associated with greater change in inflow than left-sided lesions (P < 0.01). In 31 patients (36%) we initially showed contralateral anterior cerebral artery (ACA) filling, and in 39% of these, normal filling was restored after stenting. Lesser contralateral carotid stenosis was associated with crossed ACA filling and with restoration of normal filling pattern after stenting. Faster appearance of a contrast-medium blush is seen in most cases of carotid angioplasty and stenting and depends on the degree of hemodynamic inflow obstruction relieved by stenting.