The treatment of cerebral ischemia by external carotid artery revascularization.

Thirteen patients with internal carotid artery occlusion and symptomatic external carotid artery stenosis underwent external carotid artery revascularization by means of endarterectomy (n = 10) or subclavian artery--external carotid artery bypass (n = 3). All patients but one were followed up, for five to 46 months (mean, 20 months). There were no operative deaths or complications and no late strokes. One patient (7.7%) required early extracranial-intracranial (EC-IC) bypass for failure of the external carotid artery endarterectomy to relieve the initial symptoms. All remaining patients were completely (n = 9) or partially (n = 2) relieved of symptoms, and EC-IC bypass was not required. There were no criteria identified by either oculopneumoplethysmography or angiography that could reliably predict the need for subsequent EC-IC bypass. Ninety-two percent of the patients were adequately treated with external carotid artery revascularization alone, suggesting that subsequent EC-IC bypass is seldom required in patients with ipsilateral internal carotid artery occlusion and external carotid artery stenosis.