Special problems in pulmonary atresia with ventricular septal defect: extreme hypoplasia of intrapericardial pulmonary arteries and autofocal collateral vessels.

4 patients with pulmonary atresia and ventricular septal defect are presented, who were selected from a group of 50 patients in whom intrapericardial pulmonary arteries were present. In 2 patients the pulmonary arteries were not only extremely hypoplastic but also displayed only minimal anastomoses with the arterial hilar vessels. They were considered not to be accessible for corrective surgery. In another patient about 50% of the pulmonary perfusion were supplied by collateral vessels not connected to the intrapericardial pulmonary arteries. The question is discussed, to what extent the systemic vessels are necessary for pulmonary perfusion and whether they may be all ligated at the time of corrective surgery. In the last patient anastomoses between 2 systemic vessels and the pulmonary arteries could be demonstrated, the right one of which was very hypoplastic. In this case a right-sided shunt operation combined with ligation of the collateral vessels seemed to be advisable to promote adaption of the pulmonary artery and to simplify the subsequent corrective procedure.