Decellularized Versus Standard Pulmonary Allografts in the Ross Procedure: Propensity-Matched Analysis

Background It is hypothesized that decellularization of allografts used for right ventricular outflow tract reconstruction may result in decreased valve deterioration. This study compared the durability of fresh decellularized pulmonary allografts with standard cryopreserved pulmonary allografts in patients undergoing the Ross procedure. Methods The Ross procedure was performed in 144 patients with decellularized allografts (DA) from 2005 to 2014 and in 619 with standard cryopreserved allografts (SCA) from 1990 to 2014. Propensity score matching was used to compare early and midterm clinical outcome and echocardiographic allograft function over time between the two groups. Results We matched 94 DA patients (79.3% male; median age, 34.0 years; mean follow-up, 2.4 ± 1.9 years) to 94 SCA patients (78.3% male; median age, 35.0 years; mean follow-up, 9.4 ± 4.2 years). There were no significant differences in baseline characteristics after matching. The matched DA vs SCA groups, respectively, were comparable in actuarial 5-year freedom from allograft dysfunction (85.6% [95% confidence interval {CI}, 53.9% to 96.2%] vs 93.3% [95% CI, 85.7% to 96.9%], p  = 0.892), freedom from allograft reintervention (98.8% [95% CI, 91.7% to 99.8%] vs 95.5% [95% CI, 88.5% to 98.3%], p  = 0.383), survival (95.3% [95% CI, 87.8% to 98.2%] vs 97.7% [95% CI, 91.3% to 99.4%], p  = 0.323), and event-free survival (83.5% [95% CI, 70.6% to 91.1%] vs 84.5% [95% CI, 75.2% to 90.5%], p  = 0.515). Longitudinal echocardiographic analyses showed a similarly modest increase in allograft gradient and regurgitation grades over time in both groups, although direct statistical comparison was not possible. Conclusions Up to 5 years of follow-up, DA and SCA used for right ventricular outflow tract reconstruction in the Ross procedure are associated with comparably excellent clinical and hemodynamic outcome. Longer follow-up and dedicated echocardiographic studies will shed light on the long-term performance of DAs.