Novel technique for innervated abdominal wall vascularized composite allotransplantation: a separation of components approach

Objective: Applications for Abdominal Wall Vascularized Composite Allotransplantation may expand if a functional graft with decreased immunosuppressive requirements can be designed. We hypothesize that it is anatomically feasible to prepare a functional, innervated, and vascularized abdominal composite graft using a multilayered component separation technique. Including vascularized bone in the graft design may decrease the immunosuppressive requirements by inducing immunologic chimerism. Methods: Two cadaver torsos were used. Adipocutaneous flaps were elevated from the midaxillary lines, preserving deep inferior epigastric artery perforators. A 2-layered component separation through the external and internal oblique fasciae was carried out, exposing segmental intercostal thoracolumbar nerves. Superiorly directed muscle release over the subcostal margin provided for a 3-rib segment with attached rectus abdominis muscle. The remainder of the full-thickness allograft was harvested with its vasculature. Flap inset into the recipient cadaver abdomen, with osteosynthesis fixation between donor and recipient ribs, was achieved. Results: The harvested grafts had an average size of 845 ± 205 cm2 with a total procurement time of 110 minutes. On one cadaver, 4 thoracolumbar nerves were isolated bilaterally, while the other cadaver yielded 3 nerves. The nerves were transected with an average length of 5.7 ± 1.2 cm. The graft vasculature was transected with a length of 4.40 ± 0.10 cm. Conclusion: Using the principles of component separation technique, we demonstrated a novel approach to harvest and transfer a neurotized osteomyofasciocutaneous abdominal wall allotransplant as a multipedicled, single functional unit.