Allografts and xenografts for right ventricular outflow tract reconstruction in Ross patients

Objectives: Pulmonary allografts (AG) are the gold standard for right ventricular outflow tract (RVOT) reconstruction during the Ross procedure. However, there is limited availability of AG in some countries, and the use of alternative grafts for RVOT reconstruction remains controversial. This study aimed to compare the rates of freedom from RVOT graft dysfunction for AG and diepoxide-treated pericardial xenografts (DPXG).

Methods: Between 1998 and 2015, 793 adult patients underwent the Ross procedure in our centre. Using propensity score matching, the clinical outcomes and echocardiographic results of AG and DPXG were compared.

Results: Propensity score matching resulted in 2 groups (AG and DPXG) of 122 patients each. No difference was found in early mortality (2.5%) in both groups. The freedom from RVOT graft dysfunction curves were comparable between the AG and DPXG groups (P = 0.186) and the 8-year rates of freedom from graft dysfunction were 91.8% and 82.2%, respectively. The survival rates at 8 years were 90.5% and 90.1%, and the rates of freedom from RVOT reintervention at 8 years were 100% and 96.8% for the AG and DPXG groups, respectively. At discharge and follow-up, transprosthetic gradients were significantly higher in the DPXG group. The rate of the RVOT gradient progression was also higher in the DPXG group than in the AG group (1.80 ± 0.06 vs 1.39 ± 0.04 mmHg/year, P < 0.001).

Conclusions: There was no difference in freedom from RVOT graft dysfunction by 8 years when using AG and DPXG in adult Ross patients, nor in survival and freedom from RVOT conduit reintervention. Long-term results need further evaluation.