A child with Tricuspid Atresia may ultimately undergo an operation known as the Fontan Procedure at 3-4 years of age. This directs the red, oxygenated blood to the body and the blue, oxygen-poor blood to the lungs.

There are different forms of the Fontan Procedure. In the one shown in the diagram at left, blood flow from the lower half of the body is channeled directly into the right pulmonary artery by fashioning a tunnel connecting the inferior vena cava to the pulmonary artery (notice the light blue wall with a small opening to release pressure). After entering the right pulmonary artery, the blood can go both to the left and the right lung.

The stump of the superior vena cava is attached to the right pulmonary artery in this procedure, allowing all systemic venous blood (shown in blue) to flow directly into the pulmonary arteries, bypassing the heart.

In many heart centers, this operation is done in stages. Usually the superior vena cava is attached first. This is referred to as a bi-directional Glenn operation or a hemi-Fontan. When the blood from the lower half of the body is channeled up to the lungs, this completes the Fontan.