Carotid Occlusion Surgery Study "COSS"


Phase 3 Results

Summary of Purpose

The purpose of this study is to determine if extracranial-intracranial bypass surgery when added to best medical therapy can reduce the subsequent risk of ipsilateral stroke in high-risk patients with recently symptomatic carotid occlusion and increased cerebral oxygen extraction fraction measured by positron emission... Trial Stopped: Pre-specified futility boundary was reached.

Read More →

Trial Milestones

The following dates are available for this trial. Trial information last updated on 24 March 2012.

1 Jul 2002 8 Jan 2002 1 Jun 2010 1 Jun 2010 1 Mar 2012 17 Jan 2012
Start Date First Received 1st Completion Completion Verification Results

Trial Design

  • Allocation: Randomized
  • Masking: Single Blind (Outcomes Assessor)
  • Purpose: Treatment
  • Endpoint: Efficacy Study
  • Intervention: Parallel Assignment


  • Carol (Hess) Papps R.N. Carotid Occlusion Surgery Study Project Manager 314-362-4299 Washington University School of Medicine 660 South Euclid Campus Box 8111 St. Louis, MO 63110