Norwood Procedure

In hypoplastic left heart syndrome (HLHS), the left side of the heart is too small to work: the mitral and aortic valves are narrowed or closed, the left ventricle is tiny, and the ascending aorta and arch are only a few millimeters across. Before surgery, blood reaches the body only through the ductus arteriosus, so the baby is kept on a prostaglandin infusion to hold the ductus open. Without surgery (or a heart transplant), HLHS is fatal in the first weeks of life. The Norwood procedure is the first of three staged operations, done in the first days to weeks of life; the Glenn (or hemi-Fontan) and the Fontan follow. It has three parts. The pulmonary artery is joined to the small aorta and the arch is enlarged with a homograft patch, so the right ventricle can pump to the body through one large new aorta. The atrial septum is cut out so blood returning from the lungs can cross freely. And a controlled source of blood to the lungs is made: either a modified Blalock-Taussig shunt (a 3.5 or 4 mm PTFE tube from the subclavian or innominate artery to the pulmonary artery) or a Sano shunt (a 5 or 6 mm tube from the right ventricle to the pulmonary artery). The arch work is done with deep hypothermic circulatory arrest at 18 C or with low-flow perfusion of the brain, depending on the center. This is one of the highest-risk operations in pediatric heart surgery. Bleeding, rhythm problems, low cardiac output, valve leaks, shunt clotting, seizures and stroke are among the early complications, and some babies need ECMO. For the scrub, the setup is a neonatal open-heart setup with homograft, PTFE grafts, 8-0 sutures, many fine tourniquets, tissue glue, and the possibility of leaving the chest open.