Composite tissue transplantation: what does the future look like?

Abstract

Achievements in clinical composite tissue transplantation have motivated investigation for more widespread clinical application. The first successes with facial allotransplantation and hand allografts have been reported in the past few years. The advances that have made recent clinical landmarks attainable have been based on technical understanding and expertise with complicated vascular anatomy of the tissue allografts, whereas the immunologic therapies with these grafts have mirrored standard immunosuppressive regimens and have resulted in comparable challenges with rejection and graft loss. Although life-saving solid organ transplantation offers survival advantage even when graft life is measured in years, transplants of composite tissue facial or limb allografts ideally need to achieve reliable long-term or permanent graft survival. The additional risks of lifelong standard immunosuppression including malignancy, infection, and renal failure also necessitate strategies toward drug minimization and/or tolerance. Research is necessary to develop alternate immunologic approaches unique to composite tissue allografts achieving improved graft survival and reduced lifelong exposure to immunosuppression. The fields of plastic and reconstructive surgery, trauma surgery, and burn surgery all have clinical demands that could be met by a successful and durable immunologic approach for composite tissue allotransplantation. The future of composite tissue transplantation will be dependent on the development of specialized clinical centers with expertise in transplant and reconstructive surgery, transplant coordinators, and immunologists investigating strategies for minimized immunosuppression and tolerance strategies.