We observed a case of anomalous origin of the left pulmonary artery from th
e aorta in which the media of the abnormal vessel and the main pulmonary ar
tery were fused, but without communication. This is the fifth isolated case
of repair without the use of cardiopulmonary bypass reported in the litera
ture. This pathology should be included in the aortic arch anomalies as a p
artial or complete failure of development of the left sixth arch. (C) 2001
by The Society of Thoracic Surgeons.