The Gore SCAFFOLD Clinical Study

Inclusion Criteria: * Patient is at least 18 years old at informed consent * Patient is willing and capable of complying with all study protocol requirements, including specified follow-up period and can be contacted by telephone. * Patient is willing to provide written informed consent prior to enrollment in study. * Patient is either: * Symptomatic with carotid stenosis ≥50% as determined by angiography using NASCET methodology. Symptomatic is defined as amaurosis fugax ipsilateral to the carotid lesion; Transient Ischemic Attack (TIA) or non-disabling stroke within 180 days of the procedure within the hemisphere supplied by the target vessel; OR * Asymptomatic with carotid stenosis ≥80% as determined by angiography using NASCET methodology * Patient must be considered high risk for adverse events during carotid endarterectomy Note: Additional inclusion criteria may apply Exclusion Criteria: * Patient has life expectancy of less than one year. * Patient is experiencing (or has experienced) an evolving, acute, or recent disabling stroke. * Patient has anticipated or potential sources of emboli (e.g. atrial fibrillation, known previously symptomatic patent foramen ovale (PFO), mechanical heart valve, or Deep Vein Thrombosis (DVT) treated within 6 months). * Patient has had an acute myocardial infarction within 72 hours prior to the index procedure. * Patient has a history of major, disabling ipsilateral stroke with residual deficit that may confound the neurological subject assessments. * Patient has known severe carotid stenosis contralateral to the target lesion requiring treatment within 30 days following the index procedure. Note: Additional exclusion criteria may apply