Subclavian Steal Phenomenon Associated With Vascular Ring in an Infant Who Had a Prenatally Diagnosed Right Aortic Arch With an Atretic Aberrant Left Subclavian Artery.

Vascular ring is a rare congenital anomaly in which the abnormal origin of the aorta or its branches and pulmonary arteries leads to encircling and compression of the trachea and esophagus. A right aortic arch (RAA) with an aberrant left subclavian artery is one of the most common forms of vascular ring. Here, we report a case of a prenatally diagnosed vascular ring resulting from an RAA with an aberrant left subclavian artery. When the infant was 7 months of age, the development of noisy breathing prompted further evaluation with cardiac magnetic resonance imaging that showed an atretic left subclavian artery associated with collateral retrograde flow from the left vertebral artery to the distal portion of the subclavian artery. Our findings indicate that an untreated RAA with an aberrant left subclavian artery may be associated with an increased risk of developing subclavian artery steal syndrome.