Peripheral nerve regeneration after interpositional grafting with acellular muscle

Peripheral nerve grafting is an established procedure in reconstructive surgery. Nerve grafts, however, are only available to a limited extent and patients are faced with neurologic deficits at the donor areas. Pretreated skeletal muscle has been proposed as an alternative grafting material. In nine adult Sprague-Dawley rats, a 2 cm gap of the sciatic nerve is grafted with a M. gracilis segment which has been pretreated through repeated freezing and thawing. Regeneration is evaluated after six weeks postoperatively. The results are compared to nine conventional nerve grafts. Regeneration was evident in all grafts. Histologically, the muscle grafts revealed a high proportion of connective tissue, a good vascularisation but an inferior degree of myelinisation. Morphometrically, the muscle grafts proved to be inferior according to axon counts and myelinisation. Muscle grafts provide a substrate comparable to peripheral nerves regarding the tubular architecture based on laminin. There are however no viable Schwann cells within these substitutes, which makes them inferior compared to conventional nerve grafts for peripheral nerve repair. These results are discussed with respect to further experiments concerning allogeneic nerve grafting and peripheral nerve preservation.