Pulmonary blood supply in patients with pulmonary atresia and ventricular septal defect.

The heart and lung specimens in 31 cases of pulmonary value atresia and ventricular septal defect were studied at autopsy. Three types of natural arterial blood supply to the lungs were identified: 1) ductus arteriosus (patient or ligamentous) (12 cases); 2) major collateral arteries (20 cases); and 3) diffuse small pleural arterial plexus coexisting with either ductus arteriosus or major collateral arteries (17 cases). The ductus arteriosus and major collateral arteries did not coexist in the same lung in these cases. Confluent central pulmonary arteries were present in 22 (71%) of the 31 cases, involving 7 (58%) of the 12 cases of ductus arteriosus, 14 (70%) of the 20 cases with major collateral arteries and 1 case with an aorticopulmonary window. The pulmonary trunk (atretic or patent) was identifiable in 24 (77%) of the 31 cases. A lung or lungs that connected to a ductus (or ligamentum) had a complete and unifocal intrapulmonary arterial distribution (without arborization abnormalities). Major collateral blood supply was frequently multifocal and associated with arborization abnormalities. The size of the central pulmonary arteries was not related to the type of arterial blood source but seemed to be related to the amount of blood flow actually reaching the vessels, This study demonstrated a complex systemic arterial system supplying the lungs in these cases. The size, sources and relation among the ductus, the pulmonary artery confluence, the large and small collateral vessels and the intrapulmonary system are far more varied than has ever been reported previously. Careful and thorough premortem studies are crucial if surgical intervention is contemplated.