When extracranial Carotid artery stenosis produces a transient ischemic attack or stroke, artery-to-artery embolism is the predominant mechanism. Asymptomatic significant (>50%) Carotid artery stenosis poses special clinical questions in patients scheduled to undergo general surgical or major cardiovascular operations.

Extracranial atherosclerotic disease accounts for up to 15–20% of all ischemic strokes