Late superior vena cava syndrome after superior vena cava-right pulmonary artery anastomosis. Report of four cases.

Abstract Cyanotic congenital heart disease and decreased pulmonary blood flow were palliated in four patients by superior vena cava—right pulmonary artery (SVC-RPA) shunts. Between four months and two years after SVC-RPA anastomosis, a late progressive form of SVC syndrome developed. Signs of the syndrome included facial edema, severe headaches and, in two patients, abnormal enlargement of head circumference, with increased intracranial pressure. These were associated with increasing cyanosis and hematocrit and decreasing exercise tolerance. In three patients prompt disappearance of signs of SVC syndrome and marked clinical improvement followed systemic—left pulmonary artery shunting or open-heart repair of the underlying malformation. The SVC-RPA shunt was left intact in each patient. Late, reversible SVC syndrome in patients with SVC-RPA shunts may be secondary to a progressive decrease in blood flow to the left lung. In the fourth case, a persistent left superior vena cava draining into the left atrium...