兔面神经部分缺损两端不同幅度延长对修复效果的影响.doc

兔面神经部分缺损两端不同幅度延长对修复效果的影响更新日期：2011-06-16 牙祖蒙陈宗基王建华李忠禹谭颖徽 【摘要】目的观察面神经缺损两端不同幅度延长对修复效果的影响。方法于中点切断兔面神经颊支，断点近、远段均以10 mm/10 min的速度分开延长，延长幅度分别为神经全长的0、10、20、30、40，按正交设计法配伍；延长结束后缝合神经端端外膜，近、远端延长幅度均为0%组则切除10 mm神经再回植，作为对照；第12周用肌电图、神经传导速度及组织病理改变评价修复效果。结果不管远段延长幅度如何，只要近段延长大于30，都明显影响修复效果；而近段延长幅度小于30，远段延长达40，修复效果仍不受明显影响。结论(1)面神经快速延长术是可行的；(2)神经缺损两端的延长幅度直接影响修复效果，近段延长应小于30，而远段可延长到40，可获同神经移植相近的疗效。 【关键词】缝合技术，周围神经；面神经；周围神经延长术 Experimental study of effects of elongation of proximal and distal segments of transected facial nerve on defect repair YA Zumeng, CHEN Zongji, WANG Jianhua, et al. Stomatologic Department, Xinqiao Hospital, The Third Military Medical University. Chongqing 400037, China 【Abstract】ObjectiveTo investigate the effects of elongation of proximal and distal segments of facial nerve on the result of defect repair. Methods Buccal branches of rabbit facial nerves were transected medially. With the expander designed by the authors, the proximal and distal nerve segments were lengthened separately. The elongation speed was 10mm per 10 minutes . According to the principle of orthogonal design , both the proximal and distal segments of 25 branches were lengthened up to 0%, 10%, 20%, 30%, 40%, respectively . When the elongation was completed, end to end repairs were performed. In the control group both proximal and distal segments were not lengthened (0%), 1cm segment of the nerve was cut off and then replanted. Electromyogram(EMG) of buccal muscle and nerve conductive velocity(NCV) were measured at 12 weeks to evaluate the function of the repaired nerves, and the number and diameter of regenerationed fibers were counted. ResultsSo long as the proximal segments were lengthened over 30% the evaluated parameters were significantly lower than the replantation group, and when the proximal segments were elongated within 30% , the distal segments could be lengthened up to 40% without significant decrease in the functional parameter (EMG, NCV). Conclusions Acute elongation of peripheral nerve is practical and the experimental results described above should be valuable for peripheral nerve especially for facial nerve defect repair. 【Key words】 Suture techniques, peripheral nerve; Facial nerve; Peripheral nerve elongation 周围神经延长术是修复周围神经缺损的一种新方法。国内外进行了不少相关研究，取得了一些进展。然而，神经缺损处两端不同幅度的延长对修复效果有何影响，二者的影响程度是否一样，二者的可延长极限是否相同，二者最佳的延长幅度组合怎样，迄今未见报道。笔者以兔面神经为研究对象，对以上问题进行了观察和探讨。 材料与方法 1. 动物及分组：健康日本大耳白兔13只，体重2.02.6 kg，雌雄不限，年龄68个月(第三军医大学实验动物所提供)。实验中有近段和远段延长两因素，每因素有5个水平即0、10、20、30、40(不计回缩率)。按正交设计原则，实验数为25，所用正交表为L25(56)。 2. 面神经解剖：用质量浓度为30 g/L的戊巴比妥钠静脉注射麻醉(1 ml/ kg)，按无菌操作解剖出面神经颊支，系膜保留在神经干上；游离茎乳孔附近至入肌点神经，长度6.06.5 cm。在中点切断神经，两断端朝相反方向反折以避免再连接。 3. 神经延长术：(1)神经断离后1周，其远段Wallerian 变性基本完成。同上法解剖面神经颊支，用自行研制的延长器对近、远段神经进行延长：延长器平置于神经所在平面，牵引轮与支撑轮处于同一水平线上；将神经套入支撑轮及牵引轮的槽沟中，旋拧螺帽使牵引轮离开原点，从而使神经得以延长（图1）。每延长10 min放松35 min。 4. 神经修复术：延长结束1 h 后，神经回缩基本停止，在无张力条件下进行神经端端外膜缝合。近、远端延长幅度均为0%组则切除10 mm神经再回植即神经移植术,作为修复效果评价对照组。 5. 神经修复效果评价：(1)EMG和NCV的检测：神经缝合后12周，重新解剖出面神经颊支，用丹麦产Nearomatic2000M型神经电生理仪，在直视下测定颊肌肌电图(EMG)和神经传导速度(NCV)。每次实验重复3次。(2)病理形态学观察：切取缝合点以远之神经组织，用体积分数为10%的甲醛固定，石蜡包埋，HE及甲苯胺蓝染色，光镜观察再生神经的组织学改变，对再生纤维数目、直径进行计量分析，每张切片选10个视野计数。 6. 实验设计及结果分析：应用正交设计法，每因素水平间差异用方差检验分析。 结果 1. EMG及NCV：近段神经延长幅度在30%以内的各组，不管远段延长幅度如何，EMG及NCV值与神经移植组比较都无明显差异(P0.05)；而当近段延长达40%，该二指标与神经移植组比较差异均显著(P0.05)。当