A Sano shunt is a medical device used to redirect blood and, with it, oxygen between a ventricle in the heart and a pulmonary artery. It is most commonly used to treat hypoplastic left heart syndrome, a congenital condition in which only the right ventricle of the heart is completely developed. It is usually made of a flexible material like GORE-TEX® plastic, and the changes is makes in blood routing are normally designed to be permanent. Babies and young children who require this sort of device often need periodic updates to keep their heart functioning optimally as they grow, however. In essence, it makes whichever ventricle is functioning properly the main, or primary, pumping chamber for the heart. The shunt isn’t usually able to completely heal the heart of its defects, but it provides a work-around that allows many patients to live otherwise normal lives. The Sano shunt is usually thought of as a modification of the Blalock-Taussig shunt and Norwood procedure, which are slightly larger and more commonly used on adults. Modifications in the Sano both in terms of size and placement often make it a better choice for use in pediatrics, though the determination is usually at the discretion of the patient’s medical team.
Insertion of a Sano shunt is performed in an attempt to allow a person with a heart defect to have enough oxygenated blood to pump around the body through the use of two chambers instead of the usual four. In congenital heart conditions, underdevelopment of the chambers of the heart often takes place on the left side. Oxygen is passed within the blood from the left side chambers of the heart to the lungs; when not working correctly, the left chambers provide only oxygen depleted blood to the organs of the body.
How and When It’s Inserted
During the surgery to complete the Sano procedure, a tube — also called a shunt — is inserted between the right ventricle and the right pulmonary artery. Following insertion of the shunt, the pulmonary artery becomes the main chamber for pumping blood around the body. The Sano procedure is typically used as the first stage of a treatment plan for babies and children who are not recipients of a heart transplant, and is required to successfully treat a heart defect of the left chambers.
In most cases placement of the shunt is just a first step. Usually after a few months, patients undergo the Glenn procedure, in which the superior vena cava is connected to the right pulmonary artery, and the Fontan Procedure, which directs blood from the inferior vena cava to the lungs. In most cases, though, these procedures can’t be performed until a child is at least two months old. Babies with serious defects in the chambers of the hearts might not live that long without some other intervention.
Heart defects usually occur early in the first trimester of pregnancy and in many cases the underdevelopment of the heart can often be identified early, normally though ultrasound. When medical teams are prepared, treatment can begin very soon after birth. Otherwise, any baby showing symptoms of hypoplastic left heart syndrome, such as a bluish tint to the skin, can have surgery to insert a shunt almost immediately once there’s been a diagnosis.
The Sano procedure is a modification of the Norwood procedure, originally developed by Dr. William Norwood in 1979. The modified shunt takes its name from its pioneer, Japanese physician Shunji Sano. Some of the key changes Sano made include the use of GORE-TEX® and larger shunt tubing, about 0.2 inches (5 millimeters). Treatment plans including the option of using the Sano shunt are now offered by medical professionals throughout the world.