Pulmonary arterial hypertension in cavo-pulmonary shunts

Abstract

The bidirectional Gleen shunting (an anastomosis between the superior vena cava and the right pulmonary artery) and the Fontan procedure (an operation that results in the flow of systemic venous blood to the lungs without passing through a ventricle) are done to treat several complex cyanotic congenital heart abnormalities such as tricuspid atresia, pulmonary atresia with intact ventricular septum, hypoplastic left heart syndrome, and double-inlet ventricle. Pathophysiology of the Fontan circulation leads to an obligatory systemic venous hypertension in which the superior and inferior vena cava and the mean pulmonary artery pressure are equal and generally in the range of 10 to 20 mmHg, 2 to 4 times that of normal.