The hemi-Fontan procedure is the second of three operations for children with hypoplastic left heart syndrome. It is done when the child is between four and six months of age. A heart catheterization is done before surgery to make sure that it is safe to proceed with surgery.
Why is the hemi-Fontan procedure done?
The goal of the second stage is to reduce the work of the right ventricle. After this stage, the right heart will only have to pump blood to the body because the work of pumping blood to the lungs is taken away.
How is the hemi-Fontan procedure done?
The large vein that brings blue blood back from the upper body called the superior vena cava is sewn into the blood vessel that takes blood to the lungs. Blood coming back from the upper body now flows directly to the lungs without going through the heart (1).
The Blalock-Taussig (BT) shunt (2) placed during the Norwood operation is removed.
A patch is placed over the top part of the heart's right upper chamber (3). This prevents blood from the upper body from entering the heart and blood from the lower body from entering the lungs. It also maintains a connection that is used for the final stage of the repair and greatly simplifies the last operation.
Why not perform the hemi-Fontan right away?
In a newborn baby's body, the pressure in the blood vessels in the lungs is quite high. If the hemi-Fontan was done right after birth, blood coming back from the upper body would not be able to flow to the lungs because of the high pressure.
After the hemi-Fontan
Most children tolerate this surgery very well and are able to return home about a week after surgery. The child usually looks about as "blue" as before the surgery since some of the blood returning from the body still bypasses the lungs. Children usually go home on several medicines that often can be stopped six to twelve months later.
After this surgery, most children grow and develop normally. They are not more prone to infections than other children and can be involved in all age-appropriate activities. There are no activity restrictions for toddlers and no need to stop children from being too active. Children know when they have reached their limit and will stop and rest. In general, children can return to daycare two weeks after discharge from the hospital.