Safety and Performance Evaluation of WIRION™ EPD in Patients Undergoing Carotid Artery Stenting

Inclusion Criteria: * 18 years of age * Anticipated patient life expectancy of at least 1 year * Patient or authorized representative, signed a written Informed Consent form * Patient is willing to comply with the protocol requirements * Candidate for catheter-based therapy of a single stenosis located in the internal carotid artery (ICA) or the carotid bifurcation, suitable for treatment with a single FDA-approved stent with a carotid use indication * Reference vessel diameter for intended filter location between 3.5mm and 6.0mm * An adequate "landing zone" of at least 30mm * Patients with severe symptomatic or asymptomatic carotid artery stenosis, to be ≥ 50% for symptomatic patients OR ≥ 80% for asymptomatic patients * At least one high surgical risk criteria, either anatomical or co-morbid risk factors, as listed below: Category I - Anatomical high risk factors * Recurrent stenosis after endarterectomy * Previous radical neck surgery or radiation therapy to the neck * High cervical ICA lesions or CCA lesions at or above C2 or below the clavicle * Spinal immobility of the neck * Tracheostomy or tracheal stoma * Any laryngeal nerve palsy and bilateral carotid artery stenosis Category II - Co-morbid risk factors * Contralateral carotid occlusion * Unstable angina (Canadian Cardiovascular Society class III/IV) * Congestive Heart Failure (New York Heart Association functional class III/IV) and/or known severe left ventricular dysfunction LVEF\<30% * Requires coronary artery bypass surgery, cardiac valve surgery, major vascular surgery, or abdominal aortic aneurysm repair 31-60 days post carotid stent procedure * Recent MI (\>72 hr and \<4 weeks) * Severe pulmonary disease with FEV1 of \<30% * CAD in ≥2 unrevascularized vessels with stenosis ≥70% * Age ≥75 years * Uncontrolled diabetes - Female patient with no child bearing potential or has negative pregnancy test within the previous 7 days and agrees to remain on birth control throughout the study Exclusion Criteria: * Total occlusion or near-occlusion of the target vessel * Severe lesion calcification * Presence of an alternate source of emboli * Presence of a filling defect, or angiographically visible thrombus, at target site * A greater than 50% CCA lesion proximal to the target or a distal (intracranial) lesion more severe than the target lesion * Evolving, acute or recent stroke within the last 30 days * Major stroke with a residual neurological deficit that would confound neurologic assessment * Vertebrobasilar insufficiency symptoms only * Major operation 30 days before or after the index procedure * Ipsilateral intracranial stenosis that requires treatment * Any pre-existing stent in ipsilateral carotid artery, or placement of a stent in contralateral carotid within 30 days of the index procedure * History of intracranial hemorrhage within 12 months * Any condition that precludes proper angiographic assessment or prevents femoral arterial access * Uncontrolled hypertension * Contraindication to heparin and bivalirudin, aspirin, thienopyridines * Known sensitivity to radiographic contrast media which cannot be controlled with pre-medication * History or current indication of bleeding diathesis or coagulopathy * Chronic renal insufficiency * Carotid artery dissection or aortic arch anatomical anomalies * Dementia or a neurological illness * Patient is enrolled in another drug or device study protocol that has not reached its primary endpoint * Severe pulmonary hypertension * Intra-cranial pathology (e.g., tumor, AVM. aneurysm, etc) that would make study participation inappropriate or confound neurologic assessment