A new model of end-to-side nerve graft for multiple branch reconstruction: end-to-side cross-face nerve graft in rats

Background: The effectiveness of end-to-side nerve graft for multiple branch reconstruction was confirmed using a new rat four-branch facial nerve reconstruction model with end-to-side cross-face nerve graft. Methods: Forty Lewis rats were randomly divided into four groups with different reconstruction methods for four branches (bilateral buccal and marginal branches) of the bilateral facial nerves as follows: group I (n = 12), single sciatic nerve graft with end-to-side neurorrhaphy; group II (n = 12), four cable grafts using two sciatic and two ulnar nerves with end-to-end neurorrhaphy; group III (n = 8), no repair; and group IV (n = 8), sham operation. The four groups were compared with double retrograde tracing of the facial nucleus, electrophysiological and histomorphometrical assessment of the reconstructed facial nerve. Results: Although there were no significant differences between groups I and II in the electrophysiological tests, group I showed more uniform and better reinnervation in the histomorphometrical assessment. Retrograde tracing of facial nucleus revealed significantly higher number of double-labeled neurons in group I although the total number of labeled neurons was not different between the two groups. Conclusions: End-to-side nerve graft shows a good functional recovery, requires less graft, and is easy to perform. With the availability of the side of the nerve graft itself as a nerve coaptation site, it can be an effective alternative in facial nerve reconstruction and be of great value in various kinds of peripheral nerve surgery.