AUTOLOGOUS DENATURED MUSCLE AS A NERVE GRAFT

This study examined the use of freeze-thawed muscle as a nerve graft m aterial in Sprague-Dawley rats. In Group I (n = 4), the sciatic nerve was isolated and the incision immediately closed. In Group 2 (n = 4), a 5-mm segment of the nerve was removed and immediately replaced. In G roup 3 (n = 50), a 5-mm segment of nerve was removed and muscle (2 x 2 x 5 mm, harvested from the gluteus, frozen in liquid nitrogen, and th awed in sterile water) was sutured in place. The short 5-mm segment of muscle provided an ideal situation for regeneration of myelinated ner ve. Sciatic functional indices were comparable in all groups after 8 w eeks and at I year Histologic analysis showed comparable nerve regener ation in Groups 2 and 3 at 4 months. Group 3 grafts exhibited new axon al growth distal to the repaired gap at 4 weeks; myelinated fibers wer e present at 10 weeks. At 1 year, Group 3 nerves had almost the same a xon count as contralateral nerves. However, myelin-sheath regeneration in the 5-mm muscle graft was incomplete, at 81 percent of normal, at 1 year.