A rare, congenital anomaly of the great arteries characterized by an extrapericardial vessel arising from the ascending aorta proximal to the brachiocephalic artery and terminating either in the dorsal aorta or in pulmonary arteries via a persistently patent arterial duct. The resulting connection is a systemic-to-systemic or systemic-to-pulmonary. Clinical manifestation include exercise intolerance, reduced femoral pulses, cyanosis with or without pulmonary hypertension and heart failure. Other congenital cardiovascular anomalies are often present and influence the clinical presentation.