Hypoplastic left heart syndrome (HLHS)
Unfortunately, there is no way to stimulate the left side of the heart to grow in HLHS, so the only option for these children, apart from a heart transplant, is to have the right side of the heart do all the work in the long term using a three-stage surgical procedure.
1. Norwood operation (or a variant of this, the Sano operation)
In this procedure, the outlet from the right ventricle is created by connecting the pulmonary artery with the small aorta, the small aortic arch is widened, the dividing wall between the ventricles is removed and finally blood is channelled to the lungs via an aortopulmonary shunt. This operation is performed in the first 10 days of life and is technically the most difficult step in the operation for the surgeon.
2. Glenn anastomosis
At the age of 4-6 months, the large vein in the upper half of the body (vena cava) is sutured to the right pulmonary artery. This operation is a good relief of the right main ventricle and the children usually thrive very well afterwards. In the best case, oxygen saturation is around 85%, which means that the child remains slightly cyanotic, but is otherwise doing well.
3. Total cavopulmonary anastomosis (TCPC)
The third operation is performed at around 3 years of age (2-4 years). Here, the large vein in the lower half of the body is also connected to the pulmonary artery. There are various techniques for this, the most commonly used today is total cavopulmonary anastomosis (TCPC), in which a tube (tunnel) is passed around the outside of the heart and connects the vein to the pulmonary artery. This type of venous blood supply to the lungs was first invented by the Frenchman "Francis Fontan" in the 1980s and the circulation that is achieved with it is also known as the Fontan circulation.
Hybrid procedure
Since the end of the 1990s, another treatment option has been developed in which the goal is also a Fontan circulation, but in which the first step of the treatment is stent implantation in the ductus arteriosus and a restriction of the pulmonary circulation with a surgically applied pulmonary artery banding of the right and left pulmonary artery. With this technique, parts of the Norwood operation and the Glenn operation can then be performed in a single operation, which is carried out around the 4th month of life. The Fontan circuit is then completed in exactly the same way as described above. This procedure also requires a great deal of experience, not only of the surgeon but also of the paediatric cardiologist.