面神经离断两端快速延长极限的实验研究

Expansional limitation of facial nerve: an experimental study on rabbits

目的 观察面神经离断两端的可延长极限。方法 于中点切断兔面神经颊支 ,离断处近、远段均以 10mm/10min的速度分开延长 ,采用L2 5 (5 6 )正交设计 ,设近段和远段延长 2个因素 ,每因素设 5个水平 ,即延长幅度为神经全长的 0 %、10 %、2 0 %、30 %、40 % ;延长结束后 ,近远段延长幅度均为 0 %组切除 1cm神经后回植 ,作为对照 ;其他组作神经端端外膜缝合 ;第 15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 除去回缩率 ,近段延长超过 18 7% ,远段超过 2 4 9% ,神经修复效果即明显不如神经移植组。结论 面神经快速延长是可行的 ;其缺损两端的可延长极限不同 ,欲获同神经移植相近的疗效 ,近段延长应 <18 7% ,远段可延长到 2 4 9%。

Objective To investigate expansional limitation of facial nerve Methods Buccal branches of rabbit facial nerves were transected middlly and the proximal and distal nerve stumps were lengthened seperately by the expander which was designed by the authors According to the principle of orthogonal design , 25 proximal and 25 distal stumps were lengthened up to 0%, 10%, 20%, 30%, 40% respectively , The average speed of the elongation was 10 mm per 10 minutes After the elongation were finished, end to end neurorrhaphy were performed except the 0% group in which 10 mm of the nerve wascut off and then retransplanted Fifteen weeks later, electromyogram(EMG) of buccal muscle and nerve conductive velocity(NCV) were measured to evaluate the function of repaired nerves While, the number and diameter of regenerating fibers were counted Results Compair Compare to the transplantaion group, when the proximal segments were lengthened up over 30%, the result of the repairment would be effected considerably despite the elongation of the distal segments and when the proximal segments were elongation within 30% , the distal segments could be lengthened up to 40% without signifigant decrease in the functional index(EMG, NCV) Conclusions Deducting the postexpansional retraction, the elongation limit of the proximal segments is 18 7%±2 4%, while the distal segments is 24 9%±2 5% These should be a referable indications for peripheral nerve especially for facial nerve defect reconstruction