The innominate steal syndrome.

Two patients with isolated innominate artery occlusion presented with symptoms of significant right-sided cerebrovascular insufficiency. One of these also noted progressive pain and weakness of the right upper extremity. Both were treated with dacron bypass grafts from the ascending aorta to the innominate bifurcation with complete relief of all symptoms. Unlike the subclavian steal, innominate artery occlusion induces distinct and much more significant hemodynamic alterations in extracranial arterial flow and is rarely asymptomatic. Three distinct patterns of blood flow have been described secondary to this lesion. Correction is best achieved by either innominate artery endarterectomy or dacron bypass grafting which the authors favor. Extra-anatomic bypasses represent a less satisfactory solution except in the poor risk patients. Long term relief of symptoms and patency of the reconstruction have been generally achieved by either of the recommended techniques.