User:PediHeartsAndCaths/Fontan procedure

The Fontan procedure is the third procedure in the staged surgical palliation. It is performed in children born with congenital heart disease without two functional ventricles and an effective parallel blood flow circuit.

The first stage is known as the Norwood procedure. This stage can generally involves combining the pulmonary artery and aorta to form a larger vessel for blood to get to the body. An artificial tube or shunt can be placed from this larger vessel to the pulmonary arteries so that blood can get from the heart to the lungs. The wall between the left and right atrium can be removed to allow the mixing of oxygenated and de-oxygenated blood.

The second stage is called the hemi-Fontan or the Bidirectional Glenn procedure. This intermediary stage is associated with the redirection of oxygen-poor blood from the upper parts of the body to the lungs. The superior vena cava (SVC), which carries blood returning from the upper body, is disconnected from the heart and instead redirected into the pulmonary arteries. The inferior vena cava (IVC), which carries blood returning from the lower body, continues to connect to the right atrium.

The third stage is called the Fontan procedure which involves redirecting the blood from the IVC to the lungs. At this point, the oxygen-poor blood from upper and lower body flows through the lungs without being pumped (driven only by the pressure that builds up in the veins or central venous pressure). This corrects the hypoxia and leaves the single ventricle responsible only for supplying blood to the body. There are currently three various techniques for the Fontan procedure which include: Atriopulmonary connection, lateral tunnel total cavopulmonary connection, and extracardiac conduit.

Fontan Circulation:

A normal heart system has a parallel circuit with the left ventricles pumping blood into the systemic system and the right ventricle pumping blood into the pulmonary system. This is different in the Fontan Circulation. In a Fontan Circulation, the two parallel circuits are turned into a single circuit in series because the vena cava are attached to the pulmonary artery.