ViVEXX Carotid Revascularization Trial (VIVA)

Inclusion Criteria: * The patient has a symptomatic or asymptomatic carotid artery stenosis that meets one of the following criteria: * Symptomatic: \> than or = to 50% carotid stenosis by angiography and a history of non-disabling stroke, transient ischemic attack (TIA) in the hemisphere supplied by the target vessel within 180 days of the procedure. * Asymptomatic: \> than or = to 80% carotid stenosis by angiography without neurological symptoms. * High risk for carotid endarterectomy: anatomical and co-morbid. Exclusion Criteria: * History of symptoms of stroke or TIA within 24 hours of the procedure * Extensive or diffuse atherosclerotic disease * Severe vascular tortuosity or anatomy that would preclude the safe introduction of the device