Objective: To determine the life span of cryopreserved homografts implanted in the right ventricular outflow tract and the factors influencing it.
Methods: From 1989 through 2003, we reconstructed the pulmonary valve with 301 homografts in 272 patients (median age 13 years; range 4 days-69 years). Indications were tetralogy of Fallot (136), truncus (23), Rastelli repair (11), double outlet ventricle (13), endocarditis (5), and the Ross operation (84). Median follow-up was 5.7 years (range 0-14). We analyzed possible predictors of graft replacement by simple and multiple Cox regression.
Results: Actuarial survival was 96+/-1.2% at 1, 95+/-1.4% at 5, and 94+/-1.5% at 10 years follow-up. Three homografts were explanted because of endocarditis (excluded from the analysis). Freedom from explantation was 99.6+/-0.4% at 1, 94.5+/-1.7% at 5, and 81.8+/-4.1% at 10 years. Variables, significantly related to explantation in the univariate analysis, were younger age, small graft size, implantation in a non-anatomical position, the aortic donor homograft, a shorter aortic cross-clamp time and the implantation of a second homograft. In the multiple model, non-anatomical position (P=0.001), smaller graft size (P<0.0001) or younger age (on square root scale, P<0.0001) and clamp time (P=0.01) remain as independent risk factors. Immunological variables, like blood group incompatibility, implantation of a second homograft and short warm ischemic time were not significant.
Conclusions: The life span of a cryopreserved homograft is determined by graft size (correlates with age) and the non-anatomic position (correlates with indication). In a specific patient, the second homograft performs as well as the first.