What is a Glenn Shunt?
A Glenn shunt is the second of three surgeries (following the Norwood procedure and preceding the Fontan procedure) used to treat a severe form of congenital heart disease called hypoplastic left heart syndrome, in which babies are born with a functioning right ventricle and a small, underdeveloped, nonfunctioning left ventricle.
What Happens During a Glenn Shunt?
During this operation, the Blalock-Taussig shunt placed during the prior Norwood procedure is removed, and the superior vena cava (the large vein that brings oxygen-poor blood from the head and arms back to the heart) is connected to the right pulmonary artery. Blood from the head and arms passively flows into the pulmonary artery and proceeds to the lungs to receive oxygen. However, oxygen-poor (blue) blood returning to the heart from the lower body through the inferior vena cava will still mix with oxygen-rich (red) blood in the left heart and travel to the body, so the child will remain cyanotic. This operation helps create some of the connections necessary for the final operation, the Fontan procedure.