Direct muscle neurotization after end-to-side neurorrhaphy

Over the recent years, end-to-side neurorrhaphy has reemerged in the literature for reconstructive nerve surgery. Another technique, in which interest has remained continuous during the last century, is direct nerve implantation into muscle belly, so-called direct muscle neurotization (DMN). In this work, the authors present a new technique to recover muscle innervation through direct nerve implantation into muscle belly, by means of a nerve graft, and sutured with end-to-side neurorrhaphy. They carried out experiments on 20 Wistar rats divided into two groups. In Group 1 (10 rats), on the right side, the peroneal nerve was sutured to the tibial nerve with end-to-side neurorrhaphy. Subsequently, the terminal branches of the same nerve were implanted in the anterior tibial muscle (ATM). On the left side, the peroneal nerve was severed, and the ATM completely denervated. In Group 2 (10 rats), on the right side, the same technique was used as in first group. On the left side, the normal innervation of the ATM was maintained. After 4 months, all muscles and nerves were harvested and evaluations carried out on the morphologic aspect, weight, and histology of the ATM, as well as the histology of the nerves. The authors analyzed the results, which demonstrated good reinnervation of the muscles deprived of any nerve connection.