Angiographic demonstration of complications resulting from the Waterston procedure.

The ascending aorta--right pulmonary artery anastomosis, originally introduced by Waterston as a palliative shunt to increase pulmonary blood flow in certain cyanotic congenital heart diseases, has been found to be associated with late complications in a significant number of cases. These complications include preferential distribution of most or all shunt flow to the right lung, narrowing or obstruction of the right pulmonary artery at the anastomotic site, increasing stenosis or atresia of the right ventricular outflow tract, hypoplasia of the left pulmonary artery, and obstruction of the shunt itself. A properly planned angiocardiographic study is the principal method of detection of these complications.