International Cooperative Study of Extracranial/Intracranial Arterial Anastomosis "EC/IC Bypass Study"


Phase 3 Results

Trial Description

To determine whether anastomosis of the superficial temporal artery to the middle cerebral artery decreases the rate of stroke and stroke-related death among patients with symptomatic disease of the internal carotid and middle cerebral arteries.


  • STA-MCA bypass Procedure/Surgery
    Intervention Desc: Surgical anastamosis between superficial temporal artery and middle cerebral artery.

Trial Design

International, multicenter, randomized trial of 1377 patients.

Patient Involvement

714 patients were randomly assigned to the best medical care and 663 to the same regimen with the addition of bypass surgery joining the superficial temporal artery and the middle cerebral artery.


Type Measure Time Frame Safety Issue
Primary Fatal or nonfatal stroke during mean follow-up period of 55.8 months.


National Institutes of Health