Performance of allografts and xenografts for right ventricular outflow tract reconstruction

Background. We compared the long-term durability of allografts and xenografts implanted for reconstruction of the right ventricular outflow tract. Methods. A total of 401 patients were studied from January 1974 to June 2000 (145 xeno- and 256 allografts), follow-up being 98% complete. We analyzed freedom from reoperation and allograft specific factors that may indicate degeneration. Results. The age at implantation was 2 days to 31 years (median 4.0 years). Conduit exchange rate was similar (p = 0.2) for conduit diameters less than 15 mm (41% ± 9% for allografts, 30% ± 6% for xenografts), but significantly different (p = 0.02) for diameters of 15 mm or larger (60% ± 8% for allografts, 30% ± 10% for xenografts). Diagnosis-related 20-year survival analysis showed a significantly (p = 0.01) better survival of patients with tetralogy of Fallot/pulmonary atresia (83% ± 5%) and Rastelli-type surgery (81% ± 8%) compared with patients with truncus arteriosus communis (69% ± 8%). ABO-compatibility, preservation method, and aortic or pulmonary allograft could not be identified as risk factors for allograft longevity. Conclusions. For smaller diameters (less than 15 mm), allografts exhibit no advantage over xenografts, whereas in larger diameters (15 mm or larger) allografts are the conduit of choice for the right ventricular outflow tract.