Congenital isolation of the subclavian artery in adults.

The congenital anomaly of isolation of the subclavian artery, on the left side, is associated with a right aortic arch. The subclavian artery loses its connection with the aorta and is connected to the left pulmonary artery via the ligamentum arteriosum. Subclavian steal syndrome accompanies this anomaly in a minority of patients. We report 2 cases of adults with subclavian artery isolation, one of whom was symptomatic, and we discuss the importance of recognizing its presence.