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The Norwood procedure is the first of three surgeries intended to create a new functional systemic circuit in patients with hypoplastic left heart syndrome and other complex heart defects with single ventricle physiology. The first successful Norwood procedure involving the use of a cardiopulmonary bypass was reported by Dr. William Imon Norwood, Jr. and colleagues in 1981.
Variations of Norwood procedure, or Stage 1 palliation, have been proposed and adopted over the last 30 years, however the key steps have remain unchanged. In order to utilize the right ventricle as the main blood pumping mechanism into the systemic and pulmonary circulation, a connection between left and right atria is established via atrial septectomy. Next a connection between the right ventricle and aorta is forged with the reconstruction of the narrowed outflow track using a tissue graft from the distal main pulmonary artery. Lastly, an aortopulmonary shunt is created connecting the aorta to the main pulmonary artery to provide pulmonary blood flow.
The second surgery also known as the Glenn procedure, focuses on separating the systemic and pulmonary circulation once pulmonary vascular resistance drops. This is accomplished by removing the aortopulmonary conduit followed by the creation of a bidirectional SVC-pulmonary shunt.
The third surgery is the Fontan procedure, in which the inferior vena cava is connected to the branch pulmonary arteries. After this surgery is completed, all the venous blood returning from the body flows directly to the lungs.