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. There are several ways to connect the lower body veins, described below.
Normal heart – in a healthy heart with proper blood flow, the blue droplets representing oxygen-poor blood travel to the lungs, and the red oxygen-rich droplets circulate through the body.
Lateral tunnel Fontan – sews a wall of fabric inside the right atrium to direct the blood flow to the lungs inside the heart itself.
Extracardiac Fontan – sews a tube from the inferior vena cava (main lower body vein) to the pulmonary arteries. This is the common approach used now.
Fenestrated Fontan – means a hole is created between the path of blue blood into the heart. This lets blood pass into the heart should it be needed. This is used if the pressure in the lungs is higher than desired for the Fontan surgery. The hole can close on its own or be closed in the cath lab at a later time.
Nonfenestrated Fontan – means no hole is present.