Partial heart transplantation (PHT) represents a novel and adaptable approach to cardiac surgery, allowing for patient-specific and disease-specific interventions while expanding the donor pool and improving organ stewardship. Unlike orthotopic heart transplantation, PHT focuses on replacing only the diseased portion, preserving autologous myocardial function. The successful application of PHT relies on precise procurement, effective preservation, and judicious use of immunosuppression to maintain graft viability.

A critical unmet need in pediatric cardiac surgery is the lack of durable valve replacement options with growth potential, leading to repeated high-risk reoperations as children outgrow their implanted valves. This issue is particularly evident in conditions such as truncus arteriosus, in which the most severe truncal valve pathology might necessitate valve replacement. Currently, the standard of care involves double valve replacement with cryopreserved homografts, a procedure associated with a staggering 50% 30-day mortality and a subsequent annual mortality rate exceeding 15%.¹ This clinical challenge drove the development of PHT as an alternative solution.

Previous attempts at using cold preserved homografts, also known as homovital grafts (pioneered by Yacoub and colleagues), while demonstrating promising functional durability, failed to demonstrate adaptive growth due to factors such as the absence of immunosuppression, extended warm ischemia times, and limited pediatric graft availability.² Notably, adaptive valve growth has been observed only in orthotopic heart transplants and pulmonary autografts after the Ross procedure.³ To address these key challenges and build on prior work, a piglet model was developed before the first human case, providing robust preclinical evidence supporting the feasibility of PHT.^4,5 The first human PHT was performed in April 2022 at Duke University on a 17-day-old infant with truncus arteriosus and severe truncal valve regurgitation. The operation was a success, and the transplanted PHT conduit demonstrated appropriate adaptive valve growth and functionality.⁶

In orthotopic heart transplantation, lifelong immunosuppression is necessary to prevent rejection. Although rejection predominantly affects the myocardium leading to ventricular failure, the cardiac valves are relatively spared due to the immune-privileged nature of the valvular tissue, particularly the leaflets. With PHT, the graft’s low immunogenicity and donor recellularization permit lower immunosuppressive requirements. In a patient early in the PHT experience, immunosuppression was discontinued after the first month after operation due to infectious complications from an unrelated procedure. This child continues to have a growing, fully functional valve 2.5 years later. The optimal immunosuppressive strategy for PHT remains an area of active investigation.