Long-term results after right ventricular outflow tract reconstruction with porcine bioprosthetic conduits

From 1975 to 1990, a total of 110 patients were operated for complex cardiac malformations with impaired pulmonary artery perfusion using porcine valved right heart to pulmonary artery conduits. Twelve- to 30-mm porcine valved conduits (Hancock or Carpentier-Edwards) were implanted at the age of 4 weeks to 28 years (mean 4.3 years). The patients' body weights were 2.9-68 kg (mean 15.3 kg). Early mortality was 5.5% (six patients), late mortality was 12.7% (14 patients), and 90 patients could be included in this long-term follow-up (426 patient-years). So far, 41 of the conduits had to be exchanged 4 months to 15 years (mean 6.5 years) after the first implantation. Forty-nine of the conduits are still in place. At reoperation, 38 patients received an allograft; three patients, reoperated before 1982, had a second xenograft. The main reason for porcine conduit malfunction was degeneration and/or calcification of the valves. In 11 patients, however, with 12- and 14-mm conduits implanted at a mean age of 3.1 years, a reoperation was necessary after a mean time of 6.8 years because these children had "outgrown" the conduit and needed a bigger one. We conclude that even though allografts seem to be the conduit of choice for right ventricular outflow tract reconstruction, our clinical experience shows that porcine valved conduits can be used just as well since most of them function sufficiently well for as long as 5 to 10 years, and early valve failure is relatively rare.