The fate of monocusps for right ventricular outflow tract reconstruction remains controversial. Between June, 1989 and April, 1996, we implanted a porcine aortic valve monocusp mounted on a bovine pericardial patch in 45 patients with a variety of congenital heart defects. Their ages ranged from 2 weeks to 18 years of age (mean 4.8 ± 4.7 years). There were 5 early postoperative deaths, directly related to preoperative clinical condition and unrelated to monocusp function. Thirty seven survivors have been followed for a mean follow-up of 38.5 ± 19.0 months (range 6 to 88 months). There have been no late deaths. Two patients were reoperated. The first one with absent pulmonary valve syndrome required reoperation 24 months postoperatively for severe pulmonary valve incompetence due to mismatch between the monocusp size and pulmonary valve area. The later developed severe residual infundibular stenosis and was reoperated 23 months postoperatively. The reoperations disclosed well preserved monocusps with no signs of tissue degeneration. The remaining 35 patients were all asymptomatic. Thirty-six patients have been evaluated by serial echocardiographic assessment of monocusp motion and hemodynamic function. The monocusp remained mobile in every case with no evidence of graft calcification, stenosis or dilatation. The mean peak systolic pressure gradient across the right outflow tract was 19.0 ± 5.8 mmHg. Pulmonary valve regurgitation was absent in 12 patients (33%), mild in 15 (42%) and moderate in only 9 patients (25%). In conclusion, porcine aortic valve monocusp provides excellent late hemodynamic results, effectively reducing or abolishing pulmonary regurgitation, without evidences of late stenosis. The monocusp has remained functional and synchronous with cardiac cycle up to 7 years after implantation.
Bioprosthesis; Heart valve prosthesis; Heart defects; Heart defects; Heart ventricle
