甲壳素涂层并预置引导纤维神经导管的实验研究

目的探讨甲壳素涂层并预置引导纤维神经导管修复周围神经缺损的效果。方法成年雌性SD大鼠24只，无菌条件下切断双侧坐骨神经，制成14mm的大鼠坐骨神经缺损模型。根据不同修复材料随机分为4组，每组6只。A组：甲壳素涂层并预置引导纤维的聚乳酸聚羟基乙酸共聚物（polyglycolic-lacticacid，PGLA）神经导管；B组：甲壳素涂层的PGLA神经导管；C组：单纯PGLA神经导管；D组：自体神经移植作为对照。术后4周和12周行大体观察、肌电图检查、S-100免疫组织化学染色和组织学观察，图像分析评价修复效果。结果术后4周A、B及C组观察到神经导管中有新生轴索通过，再生神经发育不成熟；D组近段有髓神经纤维均匀疏散分布，远段未见明显再生神经束形成。术后12周各组再生神经已通过神经导管长入远端，肌电图、S100免疫组织化学染色和图像分析结果表明A组再生神经轴突数量及再生神经质量优于B、C组，差异有统计学意义（P〈0．05）。D组移植神经轴突直径、髓鞘厚度、纤维密度与A、B及C组比较，差异有统计学意义（P〈0．05），但D组近段神经髓鞘部分空泡样变性及脱髓鞘改变，远段再生神经束形成少。结论甲壳素涂层并预置引导纤维的神经导管能有效修复周围神经缺损。

EXPERIMENTAL STUDY ON NERVE CONDUIT COATED WITH CHITIN AND FILLED WITH A GUIDE-FIBER

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 WTBZ]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.