Orthotopic hindlimb transplantation in the mouse.

There are many potential advantages to using a mouse as a model for composite tissue transplantation, particularly to examine the mechanisms behind various tolerance induction protocols. The purpose of this study was to evaluate the reliability of a new hindlimb transplant model in the mouse. Fifteen Swiss-Webster mice, 14 to 16 weeks old (35 to 50 g), had syngeneic hindlimb transplants performed. The donor limb was attached to the recipient limb stump first by bony fixation using an intramedullary rod (22-gauge needle, 2.5 mm in length). The venous anastomosis was performed across a stent fashioned from a 27-gauge nylon I.V. catheter tip cover and secured with two simple ties using 10-0 nylon. The arterial anastomosis was performed with interrupted 11-0 nylon stitches. Eleven of the fifteen transplanted limbs survived for the duration of the study (30 days). All four failures occurred within 4 hr postoperatively, (venous thrombosis, n = 2; arterial thrombosis, n = 2). Clamp time decreased throughout the study, averaging 56 min for the final four transplants and 88 min total operative time. Orthotopic hindlimb transplantation can be reliably achieved in a mouse. The mouse model should be useful to the future study of composite tissue allotransplantation.