Subclavian artery stenosis combined with vertebral artery stenosis may lead to compensatory blood flow changes in the contralateral vertebral artery

Abstract

To investigate the severity of blood steal and the hemodynamic profiles in patients with subclavian artery stenosis combined with vertebral artery stenosis. A retrospective analysis was performed of transcranial Doppler (TCD) data from patients with subclavian artery stenosis (SAS) and concomitant unilateral/bilateral vertebral artery stenosis (VAS, >50%) or occlusion in our institution between February, 2014 and July, 2018.Thirty-seven patients with SAS combined with VAS (SAS+VAS) were reviewed for types of blood steal, peak systolic velocities of blood flow in affected subclavian artery and the contralateral vertebral artery, and the findings of hyperemia testing.These data were also reviewed for 39 SAS patients without VAS (control group) for comparison of blood steal and hemodynamic profiles. In SAS+VAS group, 5 patients showed no blood steal; blood steal in stage Ⅰ was found in 22 patients, stage Ⅱ in 7, and stage Ⅲ in 3, as compared to the numbers of 17, 12 and 10 in the control group, respectively (H=9.431, P=0.002).The peak systolic velocity of the contralateral vertebral artery was 43.91±17.43 cm/s in SAS+VAS group, significantly lower than that in the control group (53.56±17.45 cm/s; t= 629.5, P=0.006).Hyperemia testing showed a significant difference in the negative rate between SAS+VAS group and the control group[35.1%(13/37) vs 7.7%(3/39);χ2=8.603, P=0.003). SAS combined with VAS may lead to reduced compensatory blood flow in the contralateral vertebral artery to lessen the severity of subclavian steal syndrome.