Carotid Occlusion Surgery Study
Overview
- Phase
- Phase 3
- Intervention
- extracranial-intracranial bypass surgery
- Conditions
- Stroke
- Sponsor
- University of North Carolina, Chapel Hill
- Enrollment
- 700
- Locations
- 1
- Primary Endpoint
- Surgical Group:Ipsilateral Ischemic Stroke in 2 Yrs From Randomization and All Stroke & Death Through 30d Post-surgery; Non-surgical Group:Ipsilateral Ischemic Stroke in 2 Yrs From Randomization and All Stroke & Death Through 30d Post-randomization
- Status
- Terminated
- Last Updated
- 14 years ago
Overview
Brief Summary
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 tomography (PET).
Detailed Description
The overall purpose of this research is to determine if a surgical operation called "Extracranial-Intracranial Bypass" can reduce the chance of a subsequent stroke in someone who has complete blockage in one main artery in the neck (the carotid artery) that supplies blood to the brain and has already suffered a small stroke. This surgery involves taking an artery from the scalp outside the skull, making a small hole in the skull and then connecting the scalp artery to a brain artery inside the skull. In this way the blockage of the carotid artery in the neck is bypassed and more blood can flow to the brain. In some people natural bypass arteries develop and the brain is already getting plenty of blood. These people have a low risk of stroke if they take medicine. In other people, no natural bypass arteries develop so less blood flows to their brains. This second group has a much higher risk of stroke while taking medicine, as high as 25-50% within the next two years. It is this second group of people who may benefit from having the bypass operation and who are the candidates for this study. This bypass surgery is considered experimental because it is not generally performed for this condition and it is unknown whether it leads to a decrease, an increase or no change in the risk of stroke. In order to determine if people fit into this second group of people who may benefit from the bypass operation they need to have a test called a PET scan. The PET scan measures the amount of blood that is getting to the brain and the amount of oxygen that the brain is using. The PET scan uses radioactive oxygen and water and is experimental (not approved by the United States Food and Drug Administration). If the PET scan shows that less blood is getting to the brain, there will be a 50-50 chance (like a coin toss) of receiving the bypass surgery or not. There will then be follow-up visits to the clinic one month later and then every three months for two years to check on the appropriate medical treatment that everyone will receive and to determine who has had a stroke. The study hypothesis is that extracranial-intracranial bypass surgery when added to best medical therapy can reduce by 40 percent subsequent stroke within two years in participants with recent TIA ('ministroke") or stroke (\</= 120 days) due to blockage of the carotid artery and reduced blood flow to the brain measured by PET.
Investigators
William Powers
Professor of Neurology
University of North Carolina, Chapel Hill
Eligibility Criteria
Inclusion Criteria
- •Vascular imaging demonstrating occlusion of one or both internal carotid arteries.
- •Transient ischemic attack (TIA) or ischemic stroke in the hemispheric carotid territory of one occluded carotid artery.
- •Most recent qualifying TIA or stroke occurring within 120 days prior to projected performance date of PET.
- •Modified Barthel Index \> 12/20 (60/100).
- •Language comprehension intact, motor aphasia mild or absent.
- •Age 18-85 inclusive.
- •Competent to give informed consent.
- •Legally an adult.
- •Geographically accessible and reliable for follow-up.
Exclusion Criteria
- •Non-atherosclerotic carotid vascular disease. Blood dyscrasias: Polycythemia vera ,essential thrombocytosis, sickle cell disease (SS or SC).
- •Known heart disease likely to cause cerebral ischemia (echocardiography not required). This includes the following conditions ONLY: Prosthetic valve, Infective endocarditis, Left atrial or ventricular thrombus, Sick sinus syndrome, Myxoma, Cardiomyopathy with ejection fraction \<25%. This is an all-inclusive list. The following conditions are NOT EXCLUSIONS: Atrial fibrillation, patent foramen ovale, atrial septal aneurysm.
- •Other non-atherosclerotic condition likely to cause focal cerebral ischemia.
- •Any condition likely to lead to death within 2 years.
- •Other neurological disease that would confound follow-up assessment.
- •Pregnancy.
- •Subsequent cerebrovascular surgery planned which might alter cerebral hemodynamics.
- •Any condition which in the participating surgeon's judgment makes the subject an unsuitable surgical candidate.
- •Participation in any other experimental treatment trial.
- •Participation within the previous 12 months in any experimental study that included exposure to ionizing radiation.
Arms & Interventions
Surgical group
Assigned to undergo extracranial-intracranial arterial bypass in addition to best current practice medical therapy
Intervention: extracranial-intracranial bypass surgery
Non-surgical group
Receives best current practice medical therapy
Intervention: best medical therapy
Outcomes
Primary Outcomes
Surgical Group:Ipsilateral Ischemic Stroke in 2 Yrs From Randomization and All Stroke & Death Through 30d Post-surgery; Non-surgical Group:Ipsilateral Ischemic Stroke in 2 Yrs From Randomization and All Stroke & Death Through 30d Post-randomization
Time Frame: within 2 yrs of randomization
2 yr Kaplan-Meier estimates of the proportions.Proportions expressed as percentages for reporting purposes. Ipsilateral ischemic stroke is defined as the clinical diagnosis of a focal neurological deficit due to cerebral ischemia clinically localizable within the internal carotid artery territory distally to the symptomatic occluded internal carotid artery that lasts for more than 24 hours. All stroke is defined as the clinical diagnosis of a focal deficit due to ischemia or hemorrhage clinically localizable to the brain that lasts for more than 24 hours. Death is of any cause.
Secondary Outcomes
- All Stroke(within 2 yrs of randomization)
- Disabling Stroke(within two years after randomization)
- Fatal Stroke(within 2 years after randomization)
- Death(within 2 years after randomization)
- Modified Rankin 0-1(at 2 years after randomization or end of trial. Worst case imputed for death and missing values)
- Modified Rankin 0-2(at 2 years after randomization or end of trial. Worst case imputed for death and missing values)
- Modified Barthel Index 19-20(at 2 years after randomization or end of trial. Worst case imputed for death and missing values)
- Summary SS-QOL Score(at 2 years after randomization or end of trial. Worst case imputed for death and missing values)
- Ipsilateral Ischemic Stroke in 2 Yrs From Randomization and All Stroke & Death Through 30d Post-surgery; Non-surgical Group:Ipsilateral Ischemic Stroke in 2 Yrs From Randomization and All Stroke & Death Through 30d Post-randomization(within 2 years of randomization)