Clinical and ethical considerations for pediatric cardiac xenotransplantation candidates

Children with complex congenital heart disease face substantial mortality and morbidity, while access to heart transplantation remains constrained by donor scarcity. Limited mechanical circulatory support options further complicate bridging to transplantation, particularly in small infants. Cardiac xenotransplantation could provide a source of size-appropriate grafts, but its potential benefit depends upon many patient factors. This review examines clinical outcomes, pediatric preclinical evidence, and ethical considerations relevant to candidate selection, with particular attention to the single-ventricle pathway. Gene-edited porcine hearts have supported pediatric-sized nonhuman primates for months, with survival beyond 24 months in one recipient and a proof-of-concept transition to allotransplantation. Initial use as a bridge to allotransplantation may be most defensible in selected children with a poor prognosis under available palliation or mechanical support who could benefit from transplantation. Partial-heart xenotransplantation offers a separate potential application for living valve replacement. Ethical evaluation must address parental permission, the child's developing autonomy, and lifelong infection surveillance. Clinical translation requires evidence and safeguards matched to the proposed recipient population and a credible plan for subsequent treatment if xenograft function fails.