The Norwood procedure is a type of heart surgery that links the single ventricle to systemic circulation. It is predominantly performed on patients with hypoplastic left heart syndrome, mitral atresia, and other heart conditions that produce single ventricle circulation. This style of cardiac surgery is known to be complicated and is often conducted on infants with hypoplastic left heart syndrome during the first week of life.
Dr. William Norwood and his fellow surgeons first developed the Norwood procedure in the late 1970s. The technique has been perfected over the ensuing decades, but the basic components of the surgery remain the same. The Norwood procedure is one of the most commonly performed heart operations on infants with hypoplastic left heart syndrome — in which the left half of the heart is underdeveloped — and statistics state the surgery holds a 75% rate of survival.
The operation entails a rebuilding of the aortic arch, the chief blood vessel in the heart that supplies blood to the rest of the body. The vessel typically needs to be widened to promote healthier blood flow, which is accomplished using tissue from the patient or animal tissue. A tube, or shunt, is implemented and links the aorta to the pulmonary artery, the blood vessel that provides blood to the lungs. Blood flow to the heart is stopped for approximately one hour during the operation.
A series of three surgeries are conducted to treat hypoplastic left heart syndrome, of which the Norwood procedure is the first. The second surgery connects a limited number of veins from the rest of the body to the veins that transport blood to the lungs. In the third and final operation, known as a Fontan procedure, the remaining veins that were not connected during the second surgery are attached.
The Norwood procedure has also been successful in the treatment of mitral atresia, a heart disease in which the mitral valve of the heart becomes significantly constricted. Given the serious nature of these conditions, the only viable alternative to the Norwood procedure is a heart transplant. Both surgeries have been shown to be successful in treating issues of single ventricle circulation.
Recovery from the Norwood procedure is commonly a lengthy and unpredictable process. Most patients will stay in the hospital for three to four weeks following the operation. While the procedure can repair healthier blood flow to and from the heart, patients who undergo it must still take heart medications and receive regular monitoring of their condition.