The Glenn procedure is most often performed on single ventricle heart defects. It is the second step in the three step Fontan series. It is normally done around six months after birth. The goal of the Glenn procedure is to finish the redirection of blood flow from the upper body to the lungs. 1
Surgeons performing the Glenn procedure have two main goals in most cases. Make blood from the upper part of the body go directly to the lungs, to allow blood to pick up oxygen without going through the heart, and let the single pumping ventricle do less work. In the Norwood Procedure, the heart is temporarily fixed to make the right ventricle do the two jobs of pumping blood to the lungs and body. 2
During the Glenn procedure, the superior vena cava, which brings blood back to the heart from the upper part of the body, is disconnected from the heart. It is then connected directly to the pulmonary artery. The shunt, either BT or Sano, that was placed during the Norwood or similar procedure is removed. These temporary fixes allow for blood from upper body — head, neck, arms — to go to the pulmonary artery to become oxygenated. The pulmonary artery leads directly to the lungs without having to travel through the heart. Because the blood is now able to reach the lungs, the shunt is not needed anymore. 2 Other steps may take place to ensure proper blood flow as each patient’s anatomy is unique.
These steps act as hold over measure until the third stage surgery – the Fontan. This is not a cure for CHD and does not make the heart fully function as it should. To learn about normal heart anatomy, read our blog How My Heart Works.
In 1958, William Glenn reported his first successful use of the classic Glenn procedure in a living human. It was done on a seven year old boy with a single ventricle, TGA and pulmonary stenosis. The current surgery is a slight modification on the classic procedure. It is now commonly called the bidirectional Glenn. 3
The Glenn procedure offers an amazing hold over period for those with single ventricle heart defects until they are ready for their Fontan.