Aortic Origin of the Right Pulmonary Artery

Abstract

The clinical course and pathologic findings in three cases of anomalous origin of the right pulmonary artery from the ascending aorta are described. The malformation is characterized by (1) absent right branch of the pulmonary artery, (2) a single large vessel arising from the ascending aorta, entering the hilus of the lung and constituting its sole arterial blood supply, and (3) normal size and structure of the right lung. A review of the literature indicates the rarity of this lesion as an isolated anomaly; patent ductus arteriosus is the most frequently described additional defect. Histologic examination of the right and left lungs reveals bilateral and symmetrical pulmonary vascular changes, despite the difference in their arterial supply. Some pathophysiologic observations based on the necropsy findings in these cases are discussed. Early diagnosis and surgical correction are imperative, since this malformation may lead to irreversible congestive heart failure and death in infancy. Surgical repair may be accomplished by transplanting the anomalous right pulmonary artery from the aorta to the main pulmonary trunk.