【摘要】 背景:改善局部微环境及减少局部瘢痕有利于周围神经再生促进神经功能恢复。目的:评价新鲜羊膜促进周围神经损伤后再生的效果。方法:选用成年SD大鼠60只,制备单侧坐骨神经急性损伤模型,随机分为人羊膜组、生物膜组、空白对照组,每组20只,均在显微镜下行神经吻接术,吻接处给予人新鲜羊膜、生物膜包裹,空白对照组修复神经后不做任何处理。术后2,4,8,12周行大体观察、光镜观察、免疫组织化学检测;术后4,8,12周行透射电镜观察、轴突成像分析、复合肌肉动作电位检测、坐骨神经功能指数测定。结果与结论:(1)大体观察:术后2周羊膜、生物膜局部稍有吸收,4周大部吸收,8周完全吸收。人羊膜组、生物膜组神经和周围组织稍有粘连且粘连较疏松,活动度可。空白对照组神经和周围组织广泛紧密粘连,钝性不易分离,活动度差;(2)光镜观察:术后2,4,8,12周,人羊膜组、生物膜组神经恢复情况明显优于空白对照组;(3)电镜观察:术后4周,3组神经纤维再生均不明显,板层结构均不清晰。术后8,12周,与空白对照组比较,人羊膜组、生物膜组神经纤维再生数量更多、髓鞘厚度厚、板层结构更清晰、轴突直径更大;(4)免疫组织化学检测:人羊膜组、生物膜组中S-100蛋白表达及分布均优于同时期空白对照组;(5)轴突图像分析:人羊膜组、生物膜组神经吻合口远端有髓神经纤维直径、髓鞘厚度及横截面有髓神经纤维数目均优于同时期空白对照组,差异有显著性意义(P<0.05);(6)神经电生理检测:与空白对照组比较,人羊膜组、生物膜组潜伏期短、波幅高及神经传导速度快,差异有显著性意义(P<0.05);(7)坐骨神经功能指数:人羊膜组、生物膜组坐骨神经功能指数均明显高于同时期空白对照组,差异有显著性意义(P<0.05);(8)结果表明,人羊膜作为一种生物材料修复周围神经损伤效果较好,可以减轻受损神经与周围组织的粘连和减少神经吻合处的瘢痕形成,可促进神经纤维再生、轴突直径增大、髓鞘增厚,可以减轻神经切口处炎性反应、免疫反应。更多还原

【Abstract】 BACKGROUND: To improve local microenvironment and reduce local scars is conducive to peripheral nerve regeneration that promotes nerve function recovery. OBJECTIVE: To evaluate the effect of fresh amniotic membrane on the regeneration of tinjured peripheral nerve. METHODS: Sixty healthy Sprague-Dawley rats were randomly divided into three groups(n=20 per group) after constructing a model of sciatic nerve injury of the unilateral leg. In group A, the nerve was wrapped with fresh human amnion at the anastomosis end after the repair of nerve. In group B, the nerve was wrapped with biofilm at the anastomosis end after the repair of nerve. In group C, no treatment was conducted after the repair of nerve(blank control). The effects were evaluated by anatomical observation, light microscope observation, immunohistochemical detection(2, 4, 8, 12 weeks after surgery), transmission electron microscope observation, axon imaging analysis, action potential detection, and sciatic nerve function index(4, 8, 12 weeks after surgery). RESULTS AND CONCLUSION:(1) Gross observation. The amniotic membrane and biofilm were absorbed partially at postoperative 2 weeks, mostly at postoperative 4 weeks and completely at postoperative 8 weeks. In the groups A and B, the nerve was adhered slightly and loosely to the surrounding tissues, with a fair range of motion. In the group C, the nerve was tightly adhered to the surrounding tissues, with a poor range of motion.(2) Observation under light microscope. The nerve regeneration was better in the groups A and B than group C at 2, 4, 8, 12 weeks postoperatively.(3) Observation under electron microscope. Regenerated nerve fibers were rarely seen and lamellar structures were unclear in the three groups at 4 weeks postoperatively. Then, increased regenerated nerve fibers, thickened myelin sheath, clear lamellar structure and enlarged axon diameter were found in the groups A and B compared with the group C at 8 and 12 weeks postoperatively.(4) Immunohistochemical detection. The expression and distribution of S-100 protein in the groups A and B were better than those in the group C.(5) Axon image analysis. Groups A and B were superior to the group C in the diameter of myelinated nerve fibers, thickness of myelin sheath and number of regenerated nerve fibers. There was a significant difference by statistical analysis(P < 0.05).(6) Electrophysiological examination. Shorter latency period, higher amplitude and faster nerve conduction velocities were observed in the groups A and B compared with the group C(P < 0.05).(7) The sciatic function index. The sciatic function index in group A or B was significantly higher than that in group C(P < 0.05). To conclude, the human amniotic membrane can reduce adhesion between the damaged nerve and surrounding tissues, and prevent scarring at the anastomosis end. In addition, it promotes the regeneration of nerve fibers, increase axon diameter and myelin sheath thickness, and ease inflammatory and immune responses at the neural incision.更多还原