Anastomosis of the ascending aorta to the right pulmonary artery, the so-ca
lled Waterston shunt, was undertaken as a palliative procedure for children
with cyanotic congenital heart disease due to obstruction of the pulmonary
outflow tract with reduced pulmonary blood flow. We present the clinicopat
hological correlations in two patients who underwent construction of Waters
ton shunts as neonates, and subsequently died of ruptured pulmonary aneurys
ms in adult life. Rupture should, therefore, be recognized as a late compli
cation of this procedure, and be considered in the long-term follow-up of s
uch patients, especially when the shunted lung is hypertensive.