Extracranial-intracranial arterial bypass for treatment of occlusion of the internal carotid artery.

Extracranial-intracranial arterial bypass was frequently utilized in the 1970s and early 1980s to treat patients with atherosclerotic occlusive carotid arterial lesions not amenable to extracranial arterial revascularization procedures. After a large randomized trial reported in 1985 that there was no benefit of surgery in these patients, the procedure was generally abandoned as a treatment for symptomatic atherosclerotic cerebrovascular disease. In the past two decades, multiple studies have shown that patients with impaired cerebral hemodynamics distal to an occlusive cerebrovascular lesion have a significantly increased risk of subsequent stroke. Two new randomized, controlled clinical trials of extracranial-intracranial arterial bypass in patients with symptomatic atherosclerotic occlusive cerebrovascular disease that are using cerebral hemodynamic criteria for patient selection are currently in progress. At the present time, extracranial-intracranial arterial bypass should not be performed on these patients outside of a clinical trial.