Fontan Circulation
Treatment for SVHD involves multiple surgeries.
Treatment of single ventricle heart defects usually involves three surgeries, which aim to reroute the blood to help the body get more and more oxygen. The first surgery is performed a few days after birth, the second around 4 - 12 months old and the third, the Fontan procedure, is performed between 18 months and 3 years.
Even with corrective surgery, people with SVHD are likely to require some medications regularly, for example, blood thinners, and many may have more surgery or a heart catheter as they grow to help improve the function of their heart. Very rarely, a heart transplant may be necessary.
The Fontan procedure re-routes the blood
vessels of the heart.
The Fontan procedure re-routes the connections of the blood vessels in the heart and allows the blue blood and red blood to stay separate. The ventricle which is large enough to do a normal job is used to do the harder job of pumping blood to the body. This means the job of getting blood to the lungs must be done without a ventricle to pump, using a channel from the blood vessel into the top chamber of the heart.
Fontan physiology may cause significant morbidities years after the procedure.
Long-term side effects of Fontan circulation include lymphatic insufficiency, renal and venous insufficiency, progressive liver fibrosis, and eventual cirrhosis. And while the Fontan procedure represents a major advancement for SVHD patients early in life, it is palliative in nature, and the long-term prognosis for adults living with Fontan circulation is mostly poor. The most recent large reviews estimate 20-year mortality of at least 20% with ongoing substantial loss of life thereafter. Nearly 55% of patients will die or require a transplant or surgical revision in their early 30s.