Right aortic arch with isolation of the left subclavian artery: case report and review of the literature.

Of the right aortic arch anomalies, a right arch with isolation of the left subclavian artery is the least common. Herein we describe a 52-year-old woman in whom this anomaly was discovered during cerebral angiography for evaluation of a giant symptomatic intracavernous carotid aneurysm. Isolation of the left subclavian artery may be suggested in a patient with a right arch in whom the blood pressure or pulse in the left upper extremity is diminished. Although the isolated left subclavian artery produces the hemodynamic alterations of a subclavian steal, review of the 39 cases reported in the literature revealed only 5 patients with symptoms suggestive of vertebrobasilar insufficiency and 5 patients with weakness of the left upper extremity. Although the patient we describe had no known heart disease, congenital heart disease was present in 23 of the 39 reported cases (59%), tetralogy of Fallot occurring most frequently.