Surgical alternatives to the Fontan procedure incorporating a hypoplastic right ventricle

Frequently the definitive operation for patients with a right ventricle (RV) that is too small to support full cardiac output is a modified Fontan operation. However, other surgical options exist that incorporate a small RV in the atriopulmonary pathway when biventricular repair is not feasible because of RV or tricuspid valve hypoplasia. The risks and benefits of these options have not been well defined.

Between 1988 and 1993, 8 patients (6 with pulmonary atresia and intact ventricular septum and 2 with tricuspid valve stenosis and RV hypoplasia) underwent a cavopulmonary connection, which allowed right atrial blood to flow either to the pulmonary artery via the RV or directly via the cavopulmonary anastomosis. Age at surgery ranged from 1.5 to 9 years. The proximal right pulmonary artery was ligated in 5 patients, and the atrial septal defect was closed during the same procedure in 7 of the 8 patients. The echocardiographic right ventricular-left ventricular volume ratio ranged from 9% to 25%, and tricuspid valve z-scores ranged from 0 to -4. There were no deaths at a median follow-up of 24 months (range, 7 to 61 months). Mild exertional limitation was evident in only one patient. Postoperative echocardiograms demonstrated pulsatile systolic flow across the RV outflow tract in 5 patients and low-velocity diastolic-systolic flow in a sixth patient with extreme tricuspid valve hypoplasia. At postoperative cardiac catheterization (6 patients) right atrial mean pressures ranged from 7 to 13 mm Hg and mixed venous saturations from 62% to 70%.

Right atrial decompression via a superior vena cava-to-pulmonary artery anastomosis allows incorporation of a small RV into the pulmonary circulation and closure of the atrial septum, with excellent results to date.