Origin of the left pulmonary artery from the aorta: embryologic considerations.

We observed a case of anomalous origin of the left pulmonary artery from the aorta in which the media of the abnormal vessel and the main pulmonary artery were fused, but without communication. This is the fifth isolated case of repair without the use of cardiopulmonary bypass reported in the literature. This pathology should be included in the aortic arch anomalies as a partial or complete failure of development of the left sixth arch.