Risks of stroke and current indications for cerebral revascularization in patients with carotid occlusion.

Preventing further stroke in patients with complete carotid artery occlusion remains a difficult challenge because there is no therapy proven effective for this prevention. These patients comprise approximately 15% of patients with carotid artery territory transient ischemic attacks or infarction. Patients with symptomatic carotid artery occlusion have an overall risk of subsequent stroke of 7% per year and a risk of stroke ipsilateral to the occluded carotid artery of 5.9% per year. The presence of severe hemodynamic failure demonstrated by increased oxygen extraction fraction (OEF) of the brain, in a cerebral hemisphere distal to a symptomatic occluded carotid artery, is an independent predictor of subsequent ischemic stroke with a risk comparable to that seen in medically treated patients with symptomatic severe carotid artery stenosis.