Development of pulmonary arteriovenous shunt after superior vena cava-right pulmonary artery (Glenn) anastomosis. Report of four cases.

Four patients with cyanotic congenital heart disease who had previously undergone superior vena cava-right pulmonary artery (Glenn) anastomosis developed pulmonary arteriovenous malformations that resulted in significant intrapulmonary right-to-left shunting. This abnormality was documented by selective angiography, oximetry, and contrast echocardiogrphy. It may be a major cause of late clinical deterioration in patients treated with the Glenn anastomosis.