Origin of pulmonary artery branch from ascending aorta. Primary surgical repair in infancy.

1. Surgical repair of origin of a pulmonary artery branch from the ascending aorta should be performed as early as possible in order to prevent death from congestive heart failure or the development of irreversible pulmonary vascular obstructive disease. 2. Deep hypothermic circulatory arrest greatly facilitates surgical repair of this lesion in infancy, as is illustrated by the three cases reported herein. 3. Direct anastomosis of the ectopic pulmonary artery branch to the main pulmonary artery is the surgical technique of choice. 4. Origin of the RPA or the LPA from the ascending aorta results from origin of the RPA or LPA from the aortic sac, instead of from the confluent sixth arches. Typically, the RPA has failed to migrate leftward because of abnormal development of the wall of the aortic sac, abnormal development of the sixth arches, or both. 5. Origin of the RPA or the LPA from the ascending aorta should be distinguished from origin of the "RPA" or of the "LPA" from the innominate artery or from the aortic arch via a PDA or a collateral artery.