Carotid Artery Stenting With Protection Registry

Inclusion Criteria: * Age greater than 18 and less than 90 * Symptomatic as evidenced by transient ischemic attack or non-disabling stroke in the hemisphere supplied by the target vessel within 180 days of procedure. Must have anatomic stenosis greater than 70% by ultrasound or angiography performed in previous 30 days * Asymptomatic patients with a stenosis greater than 80% by ultrasound or angiography performed in previous 30 days * Patient has no childbearing potential or has negative pregnancy tests within one week prior to procedure. * Patient and patient's physician agree to have the patient return for all the required clinical contacts following study enrollment * Patient signs informed consent * Patient has been excluded from other multi-institutional trials Exclusion Criteria: * Patient has evolving stroke or intracranial hemorrhage * Allergy to trial required medications * Active bleeding diathesis or coagulopathy, or will refuse blood transfusions * History of major ipsilateral stroke with sufficient atrophy to increase risk of procedure associated bleed * Severe dementia * Previous intracranial hemorrhage or brain surgery within the past twelve months * Patient has any condition that precludes angiography or would make a percutaneous procedure unsafe * Patient or family inability to understand or cooperate with study procedures * Recent GI or remote bleed that would interfere with anti-plate therapy * Severe vessel tortuosity or calcification that would preclude introduction of guiding catheter, guiding sheath, or stent placement * Extensive diffuse atherosclerotic disease involving the arch or common carotid that would preclude safe introduction of catheters and sheaths for endovascular therapy * Intraluminal filling defect * Intracranial aneurysm greater than 6 mm, AVM, or other intracranial vascular abnormality that would preclude safe intravascular intervention