Persistent left fifth aortic arch with pentalogy of Fallot.

Congenital double-lumen aortic arch resulting from persistence of the fifth aortic arterial arch (PFAA) is a rare congenital anomaly. It appears as a vascular structure running inferior and parallel to the "real" aortic arch from the innominate artery to the left subclavian artery. We report a case of persistent fifth aortic arch (systemic-to-systemic arterial connection) with pentalogy of Fallot in a patient who underwent successful intracardiac repair with a transannular patch with very proximal aortic cannulation for cardiopulmonary bypass (CPB).