Aberrant left pulmonary artery.

IN ANOMALOUS or aberrant left pulmonary artery, the main pulmonary trunk arises in a normal manner from the right ventricle and passes upwards and to the right as the main pulmonary artery. It then lies anterior and to the right of the trachea in the vicinity of the carina. At this point the aberrant left pulmonary artery arises and passes over the right main bronchus and behind the trachea, anterior to the esophagus, compressing these structures and sometimes the left main bronchus to a variable degree as it courses to enter the hilus of the left lung (Fig 1). The earliest reports of this malformation are of necropsy specimens.1-3The anomaly was first recognized during life in 1953 by Welsh and Munro4and by Potts and his associates.5The latter group demonstrated that this condition was amenable to surgical correction and emphasized the importance of this cause