How is hypoplastic left heart syndrome treated?
Babies with this condition will die within days to weeks if they are not treated. Babies can be treated in a series of operations that re-route the function of the left side of the heart. Heart transplantation is another option, though it is limited by the number of infant hearts that are available. Children who have a heart transplant must take drugs to prevent organ rejection for the rest of their lives.
Once the baby is born, three surgical procedures—which are timed to coincide with the development of the lungs—are performed:
- The Norwood Procedure: This surgery, which re-routes the blood flow to avoid the left side heart problems, is performed shortly after the child is born. The surgery turns the right ventricle—the non-defective ventricle—into the main “workhorse” ventricle that will pump blood to both the lungs and the body. The main pulmonary artery and the aorta are surgically connected with a shunt (tube), linking a branch of the aorta or the right ventricle to the pulmonary artery to supply blood to the lungs. Oxygenated blood is supplied to the body through other branches of the aorta.
- Bi-directional Glenn Operation: This operation usually is performed about three to six months after the Norwood procedure, when the lungs are more mature and don't require ventricular force to send blood to the lungs. During this operation, the shunt to the pulmonary arteries is disconnected and a new shunt attaches the superior vena cava (major vein that drains de-oxygenated blood from the upper body to the right upper chamber of the heart) to the pulmonary artery. This new shunt diverts half of the de-oxygenated blood directly to the lungs without the need to go through the ventricle.
- Fontan Operation: This operation is usually performed about 18 to 36 months after the Glenn operation, a time when the lungs have further matured and the vessels of the lungs can accommodate all the de-oxygenated blood from the lower part of the body. This operation connects the inferior vena cava (the major blood vessel that carries de-oxygenated blood from the lower part of the body back to the heart) with the pulmonary artery. This is done by creating a channel through or just outside the heart to direct blood to the pulmonary artery. After this operation, blood flows passively through the lungs, and the single ventricle pumps exclusively oxygenated blood to the body.
The decision about which surgical approach to take will depend on:
- The baby's overall health;
- The extent of the disease;
- The surgeon's expertise;
- Expectations about how the baby's disease might develop in the future, and;
- The wishes of the parents.
Because these surgeries are complex and need to be personalized for each baby, your heart doctor will help you decide which medical and surgical approach will be best for your baby.
Two new approaches to treating hypoplastic left heart syndrome while the baby is still in the uterus are being explored:
- In a small group of fetuses in which the hole between the atria is closed, a procedure known as fetal balloon atrial septostomy opens the hole before the baby is born.
- Another group of children develop a problem with the aortic valve, which leads to enlargement of the left ventricle. The left ventricle then shrinks, causing hypoplastic left heart syndrome. One proposed surgery is to open the aortic valve before the left ventricle shrinks.
There are significant risks to these procedures, and the outcomes are still mixed.