Abstract 83: Encephaloduroarteriosynangiosis Surgery Averts Stroke in Atherosclerotic Patients With Border-Zone Stroke

Abstract

Introduction: Intracranial atherosclerotic disease (ICAD) is one of the most common causes of stroke around the world. Among patients with ICAD being treated with Intensive Medical Management (IMM), those who initially present with ischemia in border-zone areas have the highest recurrence rates (37% at one year) due to association with poor collaterals. Methods: We recently concluded a phase II clinical trial of EDAS revascularization for patients with symptomatic ICAD failing medical management (ERSIAS). EDAS creates new collaterals from the donor branches of the external carotid artery. We performed an analysis of ERSIAS patients who had stroke as qualifying event and ischemia of a border-zone area on their initial MRI. We compared their outcomes to the subgroup of patients with border-zone ischemia from SAMMPRIS. Results: Of 52 patients included in the ERSIAS trial, 35 patients presented with strokes at baseline and 28 had border-zone pattern, including 15 (54%) with exclusive border-zone ischemia and 13 (46%) with mixed patterns including the border-zone. Of these 28 patients with border zone strokes as qualifying event, three (11%) presented recurrent strokes up to one year after EDAS surgery. When compared with the matched population from the medical arm of SAMMPRIS, EDAS patients had significantly lower than expected rate of recurrence (11% vs. 37% p=0.02, OR:0.21, 95%CI= 0.05-0.84), representing an absolute risk reduction of 26%. Conclusion: When compared with matched controls on IMM, EDAS reduced the expected rate of recurrent stroke in patients at the highest risk of recurrence. This supports the concept that EDAS might avert strokes due to hypoperfusion by generating new collaterals to ischemic cerebral territories and could supplement IMM in patients with border-zone infarctions due to ICAD.