Cryopreserved allogeneic vessel and nerve grafts: hind-limb replantation model in the rat

The authors have previously reported the permanent storage of skin and cutaneous flaps using cryopreservation. In this study, replantation of the hind limb was performed in rats, using an allogeneic femoral artery, vein, and sciatic nerve which had been cryopreserved for more than 3 weeks. Femoral arteries, veins of 2 cm in length, and sciatic nerves of 1.5 cm in length from Lewis rats were cryopreserved for more than 3 weeks to decrease antigenicity. The hind limb of a Brown Norway rat was completely amputated at its mid-length and the cryopreserved artery, vein, and nerve were interposed in the anastomosis of the femoral artery, vein, and sciatic nerve. Immunosuppressants were not used. Hind limbs were replanted in six rats, and all cases survived. Toe spread and gait-foot analysis revealed good results at 3 months postoperatively. Excellent axonal regeneration was observed in the pathologic examination of the sciatic nerve 1 cm distal to the transfer. This report introduces a long-term storage method for vessels and nerves and extends the possibilities for clinical use of cryopreserved vessels and nerves, using replantation in a rat model.