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Abnormal connections between the inferior vena cava, or right or left superior venae cavae to the right or left atrium may occur. A right-side anomaly (e.g., persistent left superior vena cava to the coronary sinus or azygos continuation of the inferior vena cava) may be of no consequence and require no treatment, although when other intracardiac anomalies require repair, the right-side abnormality may require an alteration in cardiopulmonary bypass cannulation techniques. When systemic veins connect to the left atrium, there is a right-to-left shunt with cyanosis, and repair is necessary. With a persistent left superior vena cava that connects directly to the left atrial roof (also known as unroofed coronary sinus), ligation of the structure obliterates the intracardiac shunt but is dangerous unless there is a normal innominate vein or large collateral connections in the head that allow unobstructed left head and neck flow into the heart. This left cava otherwise can be anastomosed directly to the right superior vena cava in certain circumstances or requires intracardiac tunneling to the right atrium.

Diagnosis of secundum atrial septal defect (ASD) is made by echocardiography and cardiac catheterization is reserved for the rare case in whom evaluation of hemodynamics is needed. If the ASD measures 5 mm or more, repair is recommended. In those defects that are smaller, repair is indicated with associated right ventricular (RV) dilatation or other evidence of RV volume load. In most centers today, closure of this anomaly beyond infancy is offered by the invasive cardiologist using one of a variety of prosthetic devices. Long-term results are being evaluated for this technique. Certain anatomical features contraindicate device closure and complications, including early failure of closure or residual ASD, early or late thromboembolism, serious arrhythmias, aortic insufficiency, interference with mitral valve function, or erosion of the device with catastrophe, convince many families to use the long-tested and reliable technique of surgical repair.

In the pediatric population, surgical repair of the tricuspid valve may be required for tricuspid insufficiency or stenosis, Ebstein’s anomaly, or other rare lesions. Operations are carried out working through a right atriotomy using cardiopulmonary bypass, moderate hypothermia (26°C), aortic cross-clamping and cardioplegia, profound local cardiac cooling, and left ventricular venting. Children with tricuspid atresia require single ventricle surgery and this is covered in Chapter 6.

Babies born with these anomalies have a deficiency of the atrial septum, ventricular septum, and/or abnormalities of the atrio-ventricular (AV) valves. In partial AV canal defect, there is absence of the septum primum and usually a cleft in the anterior mitral leaflet. This anomaly is synonymous with primum atrial septal defect. The intermediate form of AV canal encompasses a primum atrial septal defect, ventricular septal defect usually in the inlet position, and usually a cleft mitral valve. The annulus between tricuspid and mitral valves is intact. In complete AV canal, the primum atrial septal defect is in continuity with a high ventricular septal defect because there is no annular continuity of mitral and tricuspid valves. This results in a single intracardiac AV valve that functions as both mitral and tricuspid valves. All patients have a significant left-to-right intracardiac shunt and in the presence of complete AV canal there is always severe pulmonary hypertension with or without AV valve regurgitation. Early surgery is necessary because of congestive heart failure and, in the presence of pulmonary artery hypertension, to avoid early development of pulmonary vascular obstructive disease.

Repair of ventricular septal defects (VSD) is performed with cardiopulmonary bypass and moderate hypothermia, aortic cross-clamping with cardioplegia, and profound local cardiac cooling. In small infants with associated complex anomalies, maximal exposure may be gained with cardiopulmonary bypass, deep hypothermia, and low-flow cerebral perfusion (about 0.25–0.5 L/min/m) because total circulatory arrest is almost never used. The two cavae are selectively cannulated, and this allows work within the heart to progress during cooling and rewarming.

A Fontan operation is used for patients who have a variety of anomalies with single ventricle including, but not limited to, tricuspid atresia or hypoplastic left heart syndrome. After the repair is complete, the single ventricle is in continuity with the systemic circulation, and the systemic venous return flows to the lungs without passing through a functional ventricle.

Pulmonary stenosis can occur at one or more sites from the proximal right ventricular outflow tract to the peripheral pulmonary arteries. Valvar obstruction and peripheral pulmonary stenosis are usually treated by closed balloon angioplasty; however, surgical repair is performed in many patients, especially those in whom operation is carried out for associated anomalies.

Infants born with this anomaly have inadequate pulmonary blood flow (caused by pulmonary valve atresia) and severe right ventricular hypertension, unless tricuspid insufficiency allows decompression of the ventricle. Initial resuscitation includes maintenance of ductus arteriosus patency with prostaglandin E.

Primary total repair is the operation of choice for patients with tetralogy of Fallot. Initial palliation with a systemic-to-pulmonary artery shunt or right ventricular outflow tract reconstruction with later corrective surgery may be indicated in the presence of hypoplastic pulmonary artery branches or a left anterior descending coronary artery that arises from the right coronary artery and traverses the right ventricular outflow tract. Shunts are also useful in the management of small children with associated cardiac anomalies, which may be more safely repaired at an older age [i.e., tetralogy of Fallot with complete atrio-ventricular (AV) canal].

Double outlet ventricle is present when all of one great vessel and more than 50% of the second great vessel arise from one ventricle. The presence of pulmonary stenosis protects the lungs from overperfusion, and in its absence the lungs are flooded and there is congestive heart failure. Total correction is undertaken at any age when symptoms dictate. Surgery is performed with cardiopulmonary bypass, moderate hypothermia, aortic cross-clamping, and cardioplegia with local cardiac cooling.