10 Fontan Surgery : Experience of One Cardiovacular Center

In order to establish a normal, in-series circulation physiologically, very different from the circulation in parallel which the children are born with single ventricle, doctors Fontan and Baudet (2) and Kreutzer (3) concurrently developed surgical treatment of patients with tricuspid atresia to achieve a passive flow through the pulmonary vascular bed (1). Management strategies for patients with functional single ventricle required a staged group of procedures where the ultimate goal is to have a single ventricle with a working pressure and volume close to normal as well as normal systemic oxygen saturation (1). It is known that both vascular development and lung maturation are essential for achieving benefits of cavopulmonary connection; the time of surgery has been defined arbitrarily and even more time to transition between partial to total cavopulmonary connection (1). Single ventricle or univentricular heart anatomically or physiologically characterized by:  Both atrioventricular valves attached to a single systemic ventricular chamber  Severe stenosis or atresia of the atrioventricular valves  There is no separation between the ventricles  One of the ventricles is hypoplastic or absent The essential characteristics of hypoplastic left heart syndrome syndrome are: 1. Stenosis or atresia of the mitral valve 2. Underdeveloped severely hypoplastic left ventricular 3. Stenosis or aortic valve atresia 4. Small aortic root 5. Ductal dependent for systemic blood flow Thus, patients with these syndromes will have a parallel circulation in which the systemic and pulmonary circulations will be supplied by "mixed" blood. The following are the physiological characteristics of hypoplastic left heart syndrome:  Non-functional left ventricle  Pulmonary venous return directed to the right atrium through a patent foramen ovale, atrial septal defect or rarely, total anomalous pulmonary venous drainage  Mixed systemic and pulmonary venous return in right atrium  The right ventricle supplies the systemic and pulmonary circulation in parallel  Retrograde blood flow from the ductus arteriosus to the coronary arteries  In these patients, ductal closure would result an inadequate systemic perfusion and metabolic acidosis with progressive coronary ischemia, and death.