Fontan is a surgical treatment used for children who do not have two pumping chambers of the heart.
Blood coming back from the veins of the body is sent directly to the lungs, rather than the heart pumping the blood to the lungs. Most children with this condition will have had a bidirectional Glenn shunt to redirect blood flow from the upper body veins prior to having a Fontan procedure. The Fontan procedure completes the change in path by directing the blood flow from the lower body veins to the lungs.