[Reinnervation of pectoralis major myoflap by the hypoglossal nerve: an experimental study in rabbits].

In order to investigate the morphological, electrophysiological and histochemical characteristics of the pectoralis major myoflaps with original nerve innervation and with hypoglossal nerve reinnervation, after denervation, the model of myoflap transposition to reconstruct the tongue was adopted on 27 New Zealand white rabbits. After the myoflaps were transferred, original nerve innervation (ON), hypoglossal-genioglossus muscle branch nerve implantation (NI) and hypoglossal-genioglossus muscle neuromuscular pedicle implantation (NMP) were performed. The flaps were examined at the intervals of 4, 8, 12 weeks and 16 weeks after operation. The results showed that the denervated myoflaps were reinnervated in NI and NMP, myoflaps contracted when the hypoglossal nerves were stimulated. The histochemical properties of muscle fibers changed. Some type II fibers in the myoflaps transformed into type I fibers, but the pattern of distribution of the muscle fibers displayed mosaic and was similar to that of genioglossus muscle. In terms of speed and scope of reinnervation, the NMP was superior to the NI.