Isolated Left Brachiocephalic Artery in Transposition of the Great Arteries.

Isolation of an artery is a rare congenital defect in which a vessel arises anomalously from the pulmonary arteries rather than the aorta. Isolated left subclavian artery and (less commonly) isolated left brachiocephalic artery have been described in association with various complex congenital heart defects. We present a very unusual case of isolated left brachiocephalic artery associated with transposition of the great arteries. The case suggests that this defect arises from pathological involution of embryologic aortic arches rather than from malseptation.