Asymptomatic isolated left subclavian artery with right aortic arch. A case report.

An isolated left subclavian artery with a right-sided aorta was discovered during autopsy of a 34-year-old Black woman who had died of pulmonary tuberculosis. The left subclavian artery arose from the end of a 5 cm long, fibrous cord attached to the pulmonary trunk, and received blood by retrograde flow in the left vertebral and supreme intercostal arteries. Isolated subclavian artery with right-sided aorta may be accounted for by abnormal development and degeneration of the embryonic aortic arches.