The first is called the Norwood procedure, and that has already been explained to us (the combination of the aorta and pulmonary artery and placement of the graft.
The second is called the Gleen procedure, also called a Bidirectional Glenn procedure or Hemi-Fontan (see also Kawashima procedure), involves redirecting oxygen-poor blood from the top of the body to the lungs. That is, the pulmonary arteries are disconnected from their existing blood supply (e.g. a shunt created during a Norwood procedure, a patent ductus arteriosus, etc.). 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 heart.
At this point, patients are no longer in that delicate balance, and the single ventricle is doing much less work. They usually can grow adequately, and are less fragile. However, they still have marked hypoxia (because of the IVC blood that is not fed into the lungs to be oxygenated). Therefore most patients are referred for another surgery.
The third is called the Fontan procedure, also called Fontan completion, involves redirecting the blood from the IVC (inferior vena cava) to the lungs as well. 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). This corrects the hypoxia, and leaves the single ventricle responsible only for supplying blood to the body.
Some patients require long-term blood thinners. The Fontan procedure is palliative, not curative. But in many cases it can result in normal or near-normal growth, development, exercise tolerance, and good quality of life.[4] In most cases, patients will eventually require heart transplantation.[5]
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