[Experimental study on nerve conduit coated with chitin and filled with a guide-fiber]

Abstract

Objective: To study the result of using nerve conduit coated with chitin and filled with a guide-fiber to repair peripheral nerve defect.

Methods: Twenty-four female adult SD rats were made the model of 14 mm-gap on bilateral sciatic nerve under sterile condition. The rats were randomly divided into 4 groups (n=6), group A: polymer polyglycolic-lactic acid (PGLA) nerve conduit coated with chitin and filled with a guide-fiber as experimental group to repair 14 mm-gap of rat sciatic nerve;group B: PGLA nerve conduit coated with chitin; group C: PGLA nerve conduit; group D: autograft (control group). The repair result was evaluated by normal observation, EMG testing and S-100 histological immunostaining analysis 4 and 12 weeks after operation.

Results: Four weeks after the operation, there were new regenerated immature fibers in groups A, B and C, 12 weeks after the operation, the regenerated nerve fibers were seen to have bridged the gap. There were myelinated fibers equably distributed and rarely new generated nerve fibers in distal parts of group D. The repair result of PGLA nerve conduit coated with a chitin and filled with guide-fiber was better than that of groups B and C (P<0. 05). There was significant difference of nerve fiber diameter, thickness of myelin sheath and fiber density in group D from those in groups A, B and C (P<0. 05), but there were degenerative changes such as vacuoles in sheaths and myelin separation in proximal and few new regenerated nerve fibers in distal parts of group D.

Conclusion: PGLA nerve conduit coated with chitin and filled with a guide-fiber offers a possible substitute for the repair of peripheral nerve defect.