Abstract:

Objective To evaluate the feasibility of repairing the long defects in rabbits by double -bridging technique and chitosan-collagen chambers. Methods Thirty Chinese rabbits were divided into three groups randomly. 15 mm defects in right facial nerve of rabbits were repaired in three groups: double-bridging（groupⅠ）, nerve autografts （group Ⅱ）, and normal control （group Ⅲ）. General observation, electrophysiological study, histological study and image analysis were performed 12 weeks postoperatively. All results were used to evaluate the nerve regeneration. Results Chitosan-collagen chambers were obviously degraded 12 weeks postoperatively and there was no foreign body reaction at this stage. They also restrain the formation of neuroma and provided a good microcircumambience for nerve regeneration. The recovery of nerve regeneration were good in group Ⅰ . The nerve conduction velocity （NCV） and compound muscle action potential（CMAP） of regenerated nerve were analyzed, which showed that there was no significant difference between the group Ⅰ and group Ⅱ（P>0.05）, but they all did not recover to normal level（P<0.01）. Conclusion Double-bridging technique is a simple method for treatment of long nerve defect and its effect is certain. Chitosan-collage chambers is suitable to implant into body in order to repair a nerve defect with excellent biocompatibility.

Key words: nerve regeneration, double-bridging technique, chitosan-collagen chamber