Aberrant left pulmonary artery. Clinical and embryologic factors.

The case of an infant with a pulmonary arterial sling (or aberrant left pulmonary artery) is presented. Associated congenital anomalies found in the original patient and in each of four other patients with this lesion, identified from postmortem files, are noted. The importance of associated anomalies of the respiratory tract is emphasized, since if present, they may affect the outcome after sucessful surgical correction of the vascular lesion. Previous theories of the embryologic origin of the anomalous artery are discussed, and a new theory is presented.