应用肌膜瓣包裹、羊膜管预置聚乳酸-羟基乙酸微丝模拟周围神经再生微环境修复周围神经缺损的实验

Simulating a microenvironment of peripheral neural regeneration with polyglycolic/polylactic acid filament-filled amnion tube and pedicled epimysium flap to repair peripheral nerve defect

背景:周围神经损伤部位的微环境状况是影响神经再生的重要因素之一。周围神经损伤后,良好的神经再生微环境有利于保护受损神经元、促进轴突的有效再生。目的:应用肌膜瓣包裹、羊膜管预置聚乳酸-羟基乙酸微丝,充填大鼠自体周围神经组织浆模拟周围神经再生微环境,探讨其修复坐骨神经缺损的可行性。设计、时间及地点:随机对照动物实验,于2006-06/2007-10在广东医学院实验动物中心完成。材料:清洁级2月龄SD大鼠30只,随机分为实验组、对照组、标准组3组,每组10只,右侧为实验侧,左侧为正常对照侧。取健康、足月、顺产的新鲜胎儿羊膜(产妇知情同意)制备羊膜基质膜。用医用Vicryl缝线和羊膜基质膜制备聚乳酸-羟基乙酸微丝桥接物。方法:大鼠切除坐骨神经6.0mm,自然回缩建立坐骨神经缺损模型。实验组采用带蒂肌膜瓣、人羊膜管预置Vicryl微丝并充填大鼠自体坐骨神经组织浆;对照组采用单纯人羊膜管充填大鼠自体坐骨神经组织浆;标准组采用自体神经移植,桥接大鼠坐骨神经缺损。主要观察指标:术后8,12周行大体观察、组织学检查、胫前肌湿质量、有髓神经纤维通过率及神经电生理学检测。结果:术后12周,实验组、标准组肌萎缩有所恢复,对照组则恢复不明显。实验、标准组患侧胫前肌色泽红润,饱满富有弹性;对照组色泽相对较暗,弹性度较差。术后8,12周3组胫前肌恢复率组间比较,术后12周3组有髓神经纤维总数、截面积,神经移植体血管数和血管截面积组间比较,以及小腿三头肌复合肌动作电位幅值组间比较,差异均有显著性意义(P<0.05),其中标准组神经纤维再生质量最佳,实验组优于对照组。结论:肌膜转位、羊膜管预置聚乳酸-羟基乙酸微丝,并填充大鼠自体周围神经组织浆导管能较好的模拟周围神经再生之微环境,促进神经纤维再生,但与自体神经移植尚有差距。

BACKGROUND： The microenvironment of injured peripheral nerve was one of the most important factors that influence peripheral nerve regeneration. A favorable microenvironment for nerve regeneration would protect damaged neurons and promote axonal regeneration. OBJECTIVE： To simulate the microenvironment of peripheral neural regeneration with an amnion tube filled with polyglycolic polylactic acid （PLGA） filaments and autologous nerve tissue pulps and wrapped with a pediclad epimysium flap, and to study the feasibility to repair sciatic nerve defect. DESIGN, TIME AND SETTING： A randomized controlled study was performed in Experiment Animal Center of Guangdong Medical College from June 2006 to October 2007. MATERIALS： Thirty SD rats of clean grade and aged 2 months old were randomly divided into experimental group, control group, and standard group, with 10 rats in each group. The right side was operated, and the left side was control. Amnion was obtained from healthy, full-term, and spontaneous delivery fetus whose mothers provided the informed consent to establish amnion matrix membrane. Vicryl thread and amnion matrix membrane were used to make PLGA microfilament bridging graft. METHODS： The 6.0-mm sciatic nerve defect was bridged with different grafts, respectively： the amnion tube filled with Vicryl filaments and autologous nerve tissue pulps, and wrapped with a pedicled epimysium flap （experimental group）; the amnion tube filled with autologous nerve tissue pulps （control group）; autologous nerve （standard group）. MAIN OUTCOME MEASURES： Gross observation, histological examination, wet weight of the anterior tibial muscle, pass-through rate of myelinated nerve fibres and neural electrophysiology were assessed 8 and 12 weeks after the operation. RESULTS： At 12 weeks after operation, amyotrophy was lightly recovered in the experimental and standard groups except control group. Anterior tibial muscle at injured side was ruddy, well-stacked, and flexible in the experimental and standard groups, but the muscle was dark and poor elasticity. At 8 and 12 weeks after operation, there were significant differences in recovery rate of anterior tibial muscle between the three groups; in addition, at 12 weeks after operation, there were also significant differences in numbers of myelinated nerve fibers, cross-section area, vascular numbers of neural graft, vascular cross-section area, and compound muscle action potential amplitude of triceps surae between the three groups （P 〈 0.05）. Regeneration of nerve fiber was the well in the experimental group, then control group and standard group. CONCLUSION： The microenvironment of peripheral neural regeneration can be well simulated with an amnion tube filled with PLGA filaments and autologous nerve tissue pulps and wrapped with a pedicled epimysiurn flap, which is inferior to autologous nerve transplantation.