Sponsor elected to not pursue this indication for the study device.

The purpose of this study is to evaluate the safety and efficacy of the TriActiv® ProGuard™ System when used during a stent placement in a blockage within the carotid artery in patients considered to be at high risk for complications from surgical endarterectomy.

Patients with certain anatomic or medical conditions have a greater risk of serious complications following carotid endarterectomy (a surgical procedure that removes blockages in the carotid artery). Recently, these patients have been treated effectively with the implantation of a carotid stent (a metallic mesh tube). When implanting the carotid stent, physicians use devices called embolic protection devices to prevent particles from the blockage from flowing up to the brain. The TriActiv® ProGuard™ System is an embolic protection device that uses a small balloon to temporarily stop blood flow within the diseased carotid artery while the stent is implanted. Then, the TriActiv® ProGuard™ System removes any particles that may have been released from the blockage during stent implantation before blood flow is restored. This study will evaluate the safety and efficacy of the TriActiv® ProGuard™ System during carotid stent placement in patients who are considered to be at a high risk for complications from surgical endarterectomy.

Inclusion Criteria:

• Greater than 18 year of age
• Patient gives informed consent
• Less than 30mm stenosis in the common and/or internal carotid artery: at least a 50% stenosis if symptomatic or at least an 80% stenosis if asymptomatic
• At least one medical or anatomic condition which makes the patient a high surgical risk.

Exclusion Criteria:

• Stroke within 14 days
• Major stroke with significant residual effects
• Myocardial infarction within 72 hours
• Extensive atherosclerotic disease in the aortic arch or proximal common carotid artery
• Severe carotid artery tortuosity
• Total occlusion
• Presence of thrombus or heavy calcification in the carotid artery
• Pre-existing carotid artery dissection
• Any planned interventional or surgical procedures within 30 days
• Atrial fibrillation
• Creatinine > 2 mg/dL
• Current participation in another investigational drug or device study