Decellularized versus standard cryopreserved valve allografts for right ventricular outflow tract reconstruction: A single-institution comparison

Abstract

Standard cryopreserved valved allografts (SCAs) are recognized as the benchmark for reconstruction of the right ventricular outflow tract (RVOT). However, SCAs frequently demonstrate early valve deterioration and elicit an immune response. Decellularized cryopreserved valve allografts (SynerGraft, SG) are less immunogenetic and may be more durable. This study analyzed our results of RVOT reconstruction using SGs and compared it with the SCAs used during the same period. We reviewed the outcome of all allografts (SG and SCA) that were implanted for RVOT reconstruction at a single center from 2000 to 2005. Echocardiographic data were reviewed to evaluate valve performance. Conduit failure is defined as the need for conduit replacement or reintervention in either the catheterization laboratory or operating room. Conduit dysfunction is defined as RVOT obstruction with peak echocardiographic Doppler gradient greater than 40 mm Hg and/or grade III/IV or greater conduit valve regurgitation. Data were compared using the Wilcoxon rank sum and Fisher's exact test. From January 2000 to April 2005, 100 patients (mean age 18.6 ± 16.8 years) received SG (n=39) or SCA (n=61) conduits. The 2 retrospective nonrandomized cohorts were similar with respect to age, gender, weight, conduit indication, bypass and crossclamp time, and conduit size. Follow-up time was not significant between the 2 groups (SG, 5.7 ± 2.5 years vs SCA, 5.8 ± 2.8 years; P=.83). Early and late mortality were similar (SG, 13%; SCA, 10%; P=.75). No death was graft related. Freedom from dysfunction was superior with SG (SG, 74%, vs SCA, 52%; P=.05). Freedom from failure was also better in patients with SG (SG, 87%, vs SCA, 68%; P=.05). Freedom from explantation and more than moderate pulmonary insufficiency were significantly better for SG patients (SG, 92% and 90%, vs SCA, 78% and 68%; P=.02). This study suggests that the midterm performance of SGs may be superior to that of SCAs. Decellularization of the cryopreserved allografts may provide a more durable option for patients who need RVOT reconstruction. Further long-term follow-up is needed to see whether this decellularization process improves long-term allograft durability.