Vascularized Composite Allotransplantation: A Functional Hind Limb Model in Mice

Background: Vascularized composite allograft has emerged as a reconstructive option for patients who have suffered severe tissue loss. Animal models are critical for understanding the unique mechanisms of rejection in vascularized composite allograft. We present a functional mouse model of orthotopic hind limb transplantation using end-to-side anastomoses of the donor aorta and inferior vena cava to the respective recipient vessels. To the best of our knowledge, this approach has not been reported in the scientific literature. Materials and methods: A single surgeon performed all transplants (J.W.). A total of 13 syngeneic and 10 fully mismatched allogeneic transplants were performed without immunosuppression. Skin samples from the grafts were collected at the time of euthanasia. Results: Five syngeneic mice survived for more than 90 d after transplant. All allografts displayed clinical and histologic signs of acute rejection such as a rash at the time of graft excision. The overall technical success rate of all transplants in this study was 74% (17 of 23). Conclusions: We demonstrate the feasibility of end-to-side anastomoses of the donor aorta and inferior vena cava with functional recovery of the transplant in a mouse model of orthotopic hind limb transplantation. (C) 2020 Elsevier Inc. All rights reserved.