Conduit reconstruction of the right ventricular outflow tract. Lessons learned in a twelve-year experience.

From September 1979 to July 1991, a total of 163 patients have undergone valved conduit reconstruction of the right ventricular outflow tract when a right ventricle-pulmonary artery connection was absent or right ventricular outflow tract enlargement was required. From September 1979 through October 1984, 24 porcine valved conduits were implanted with an operative mortality of 38% (9/24). There were no early failures, but by 9 years after the operation 9 of 15 survivors (60%) had severe conduit obstruction, which resulted in death in 2 patients and reoperation in 6. From May 1985 to June 1991, 24 patients received cryopreserved aortic allografts to correct congenital anomalies. Operative mortality was 25% (6/24) and, again, early conduit function was good. There were 4 (22%) late deaths that were not related to the aortic allograft. At a mean follow-up of 3.4 years, 11 of the 13 survivors (85%) had allograft calcification and 8 of the 13 (62%) had mild to moderate conduit stenosis or regurgitation, or both; two of them required conduit replacement. Distal anastomotic problems that might have been avoided with bifurcated pulmonary allografts were apparent in 4 (36%) patients. Cryopreserved pulmonary allografts were placed in 115 patients between April 1985 and January 1991, with 18 (16%) operative deaths. Late deaths that were not allograft related occurred in 7 of 97 surviving patients (7%). Six patients (6%) underwent reoperation, 2 because of primary pulmonary allograft failure. The 84 remaining patients are free of symptoms with little or no allograft calcification or echocardiographic evidence of significant conduit stenosis or regurgitation. Experience with porcine valved conduits and aortic and pulmonary allografts suggests that pulmonary allografts are the conduit of choice for right ventricular outflow tract reconstruction.