Gene-Edited Pig Cardiac Xenotransplantation as a Bridge to Allotransplantation in Infants: Progress in a Pig-to-Baboon Model

Cleveland and colleagues present a translational study evaluating porcine cardiac xenotransplantation as a potential bridge to allotransplantation in infants with congenital heart disease. 

A total of 15 baboons underwent implantation of gene-edited porcine cardiac xenografts. The mean donor age and weight were 8.9 weeks and 8.3 kg, respectively, while the mean recipient age and weight were 20.5 months and 6.4 kg. Eligibility for xenograft explantation and subsequent allograft implantation was defined as survival beyond four months. 

Following xenotransplantation, 14 of the 15 recipients were successfully weaned from cardiopulmonary bypass, although three died within the first 24 hours. Eight of the 15 survived beyond one month with functional xenografts, with a median survival of 41 days for the overall cohort. Three recipients were selected for xenograft-to-allograft transition. Of these, one was euthanized intraoperatively due to unsuccessful pulmonary artery reconstruction, another died prior to transplantation at 242 days, and the third survived 105 days following allograft implantation. The longest overall survival in the cohort was 734 days. 

This study represents an important step forward, advancing the feasibility of cardiac xenotransplantation as a bridge strategy to allotransplantation in infants with congenital heart disease.