Background and aim of the study: The study aim was to determine the dynamics and risk factors related to cryopreserved homografts implanted to reconstruct the right ventricular outflow tract (RVOT) during the Ross procedure.
Methods: A retrospective study, conducted between 1993 and 2009, included 107 consecutive patients who underwent a Ross procedure with implantation of a homograft (102 pulmonary, five aortic). The median patient age at implant was 18.8 years (range: 2 months - 67 years). The main cardiac defects were congenital aortic stenosis (n = 44), congenital aortic regurgitation (n = 20), and combined (n = 23) and acquired (n = 20) aortic regurgitation. The study endpoints were homograft stenosis (peak gradient > or = 20 mmHg), regurgitation (grade > or = moderate), homograft dysfunction (stenosis > or = 50 mmHg or regurgitation > or = moderate), homograft explant, and failure (explant or balloon dilation). The mean follow up was 5.7 +/- 0.4 years. The statistical analysis was conducted using univariate and multivariate Cox regression tests.
Results: The overall patient survival was 97% at 18 years. Homograft stenosis occurred in 54% of patients, regurgitation in 18%, dysfunction in 27%, explant in 5%, and failure in 6%. Freedom from homograft dysfunction was 75% and 55% at five and 10 years, respectively, while freedom from homograft failure was 99% and 84% at five and 10 years, respectively. The main multivariate risk factors for dysfunction were: homograft diameter < 22 mm (OR: 11, p = 0.019), aortic homograft (OR: 18, p = 0.019) and preoperative right ventricle/left ventricle pressure ratio > 0.4 (OR: 5, p = 0.018). Univariate risk factors for failure were: homograft diameter < 22 mm (p = 0.006), donor age < 30 years (p = 0.03), cold ischemia time < 2 days (p = 0.04), and decontamination time < 12 h (p = 0.01).
Conclusion: In the Ross procedure, the cryopreserved homograft represents an excellent means to reconstruct the RVOT, with a good long-term longevity. Almost 85% of patients did not require any surgery or percutaneous intervention at 10 years after implantation. The homograft long-term durability depends on both homograft-related and patient-related factors. Pulmonary homografts, with a diameter > 22 mm, a donor age > 30 years, and a cold ischemia time > 2 days are to be preferred.