A Novel Staged Revascularization Strategy for Bilateral Severe Internal Carotid Artery Stenosis at High Risk for Hyperperfusion Syndrome.

Abstract

Since bilateral severe internal carotid artery stenosis often is associated with severely decreased cerebrovascular reactivity (CVR) due to poor collateral blood flow, revascularization carries a high risk for development of hyperperfusion syndrome. In this study, we report a new staged strategy to prevent postoperative hyperperfusion syndrome in such patients. Bilateral severe cervical internal carotid artery stenosis patients with decreased CVR to 10% or less on one side were prospectively enrolled in this study. We first performed carotid artery stenting on the side with the milder CVR decrease (lower-risk side), aiming to improve hemodynamics associated with the severe CVR decrease on the greater-risk side. Then, carotid endarterectomy or carotid artery stenting was performed on the contralateral side after an interval of 4-8 weeks. In all 3 cases enrolled in this study, CVR on the greater-risk side improved to 10% or more 1 month after the first treatment. The ratio of regional cerebral blood flow on the contralateral greater-risk side was 114% 1 day after the second treatment, and HPS did not develop in any of the cases. Our treatment strategy, in which revascularization on the lower-risk side precedes that on the greater-risk side, is effective for the prevention of HPS in bilateral ICA stenosis patients.