What Is the Glenn Procedure?

The Glenn procedure is a type of surgery that directs blood from the upper body to the artery that goes to the lungs, bypassing the heart. This surgery is most commonly performed on babies and young children with congenital heart problems, from the age of two months onwards. Although the Glenn procedure can be performed as a standalone surgery, it is commonly used as a stage in a long-term treatment plan.

Research into performing what has become known as the Glenn procedure, or partial Fontan procedure, began in the 1950s. In 1958, Dr. William W.L. Glenn reported the first successful application of the Glenn shunt being performed on a human heart at Yale University. The bidirectional shunt allows blood flowing from the head and upper portion of the human torso to pass directly to the lungs. Blood traveling around the lower portion of the body is not affected by the Glenn procedure, and travels to and around the heart as normal.

During surgery to perform the Glenn procedure, a number of veins carrying blood around the body are connected to blood vessels that move oxygenated blood to the lungs. Connections are made between the superior vena cava of the heart and the pulmonary artery; divisions are also made in the right pulmonary artery, and some of the arteries diverting blood away from required areas of the body are closed off. Following this procedure, the right pulmonary artery pumps blood solely to the lungs, reducing the amount of work the artery is required to do perform.

As the second stage commonly used in the repair of congenital heart defects, the Glenn procedure usually follows an earlier surgery or surgeries to complete the Norwood procedure. During the Norwood procedure, a shunt is inserted into the heart to increase blood supply around the body and to prepare the heart for the bidirectional Glenn. Following completion of the Glenn procedure, the Fontan procedure is often completed to direct blood returning from the lower body directly to the lungs.

The Glenn procedure is used to work around the parts of the heart that are not developed properly in babies and children and thus the amount of oxygenate blood traveling around the body to organs and tissues. Although the procedure is determined as safe for children aged two months old and up, the risks are no greater for infants and children undergoing a bidirectional shunt than for adults undergoing the surgery. This shunt does not correct a congenital heart defect, but does provide an increase in blood supply to the lungs.