Partial anomalous origin of the left pulmonary artery

The pulmonary sling or aberrant left pulmonary artery has an incidence of 3 % to 6% of all anomalies of the aortic arch system. We report a boy with co existence of a normal and an anomalous left pulmonary artery. Associated co ngenital anomalies were coarctation, mitral stenosis, and imperforate anus. Cardiac catheterization and angiocardiography at the age of 5 months demon strated an inconspicuous pulmonary trunk dividing into left and right branc hes. There was a normal right pulmonary artery, and a main left pulmonary a rtery supplying the left upper lobe, lingula, and anterior segments of the left lower lobe. In addition, an anomalous left lower lobe artery originate d from the proximal right pulmonary artery, passed inferior to the tracheal bifurcation to the left supplying posterior segments of the left lower lob e. Chest X-rays and bronchoscopy could not detect any malformation of the t rachea and pulmonary lobulation. There are only three reports of partial an omalous origin of the left pulmonary artery, and only one had a similar cou rse of the accessory artery. This report is the first to present selective angiography and echocardiographic findings of the partial anomalous left pu lmonary artery. The development of the partial anomalous pulmonary artery c an be explained by the plexiform nature of the primary pulmonary vascular b ed and can help to understand the embryology of the pulmonary arteries.