Vascularized composite allotransplantation: a new concept in musculoskeletal regeneration.

Over the past 20 years, the fields of biomaterial sciences and tissue engineering have evolved into new clinically relevant applications including regenerative medicine and cell based therapies. Tissue engineering therapies are based on different types of materials and scaffolds combined with cells and submitted to engineering processes in order to create bio-scaffolds which will improve or replace biological functions. Despite the effort, only a few therapies, such as bone, cartilage and nerve, succeeded in clinical applications. Furthermore, the major drawback in standard application of these therapies was the critical size defects which could be covered with engineered materials, as well as inability to provide sustainable vascular supply to the created bio-scaffolds. In 1998, the first successful hand transplantation was performed in France, and the field of vascularized composite allotransplantation (VCA) was introduced into the armamentarium of reconstructive surgery (Dubernard in Am J Transplant 5(6):1580-1, 2005; Petruzzo et al. in Am J Transplant 6(7):1718-24, 2006; Lanzetta et al. in Transplantation 79(9):1210-4, 2005). As a result, a new generation of transplants including hand, face, larynx abdominal wall, lower extremities and penile transplantation became available to patients who had lost these unique organs and were previously unable to achieve restored function using standard reconstructive procedures. Ethical debate on the need for life-long immunosuppressive therapy to prevent rejection of the VCA overshadowed the success of face and hand transplants. Thus, a new, challenging opportunity developed to combine approaches of tissue engineering and regenerative medicine and ultimately restore the framework, function, aesthetics and survival of the VSA transplants. This overview presents the unique opportunities of merging established and new technologies into the burgeoning field of reconstructive transplantation.