去细胞异体面神经移植修复兔面神经缺损的实验研究

Experimental studies of the conductivity recovery of the facial nerve repaired by acellular allografts in rabbits

目的:探讨化学去细胞异体全面神经修复兔全面神经缺损对面神经及肌功能恢复的作用,比较各支之间神经再生速度的差异。方法:造成兔左侧面神经主干加分支共2cm的缺损,采用去细胞异体全面神经进行外膜缝合桥接缺损,并设自体面神经原位移植作为对照。术后3、6个月进行颊支、颞支神经电生理检测以及运动终板染色,采用SPSS11.0软件包对数据进行t检验。结果:术后6个月,实验组兔面形已经基本对称,闭眼完全。实验组及对照组颊支传导速度分别为(50.63±3.28)m/s和(54.22±4.78)m/s,颞支传导速度分别为(23.95±4.83)m/s及(25.37±5.74)m/s,均无显著性差异(P>0.05)。颊支传导速度显著快于颞支(P<0.01)。口轮匝肌乙酰胆碱酯酶染色可见复甦的运动终板,每高倍视野终板的数量在实验组及对照组分别为(8±1)个和(12±3)个(P<0.05),实验组终板的纵、横径均小于对照组(P<0.01),但与健侧相比均有显著性差异(P<0.01)。结论:化学去细胞异体全面神经修复兔2cm全面神经缺损,可恢复面神经的运动及传导功能,具有潜在的临床应用前景。

PURPOSE： To investigate the autologous graft as a clinical treatment of peripheral nerve injuries, an optimized acellular nerve graft was developed which retained the extracellular structure of peripheral nerve tissue via an improved chemical decellularization treatment. Cellular component was removed from nerve, eliminating the antigens responsible for allograft rejection. The present study was to investigate the effect of chemically extracted acellular facial nerve allografts on the motor conductivity recovery of facial nerve and the revivement of motor endplates. METHODS： A 2 cm facial nerve gap was made on the left side of the rabbit, and the defect was repaired by acellular nerve allografts with epineural suture, the autograft facial nerve was used as control. Electrophysiological test and AchE staining were used to evaluate the motor evoke potential and conductivity and to observe the endplates in the orbicularis otis and frontalis. SPSS 11.0 statistical software was used to collect the data and t test was used to determine whether the difference between the averages of data sets was statistically significant. RESULTS： Six months after facial muscles of the experimental rabbits got bilateral symmetry, the blink reflex was masculine, the eyes were closed completely. In the experimental and control group, the conduction velocity of buccal branch was （50.63±3.28） m/s and （54.22±4.78）m/s, while the conduction velocity of temporal branch was （23.95±4.83）m/s and（25.37±5.74）m/s, respectively. There was no significant difference in both conditions （P〉0.05）, and the conduction velocity was similar to that on the normal side. There were many brown oval motor endplates revived in the reinnervated orbicularis oris, the number in the experimental and control group was （8±1）/HP and （12±3）/HP, with significant difference between the two groups（P〈0.05）. The longitudinal diameter and transverse diameter of the motor endplates in the experimental group were shorter than those in the control group. There were significant differences not only between the experimental group and the control group （P〈0.01）,but also between the control group and the uninjured side （P〈0.01）. CONCLUSIONS： Based on the parameters of the electrophysiological test and motor endplate staining, it suggests the nerve regeneration even over 2 cm distance of the whole facial nerve defect in rabbits, and therefore suggests potential benefit for new therapeutic strategies. Further elucidation is required to determine the limits and refinements of this technique. Supported by National Natural Science Foundation of China （Grant No. 30540046,30571875）, ＂Tenth Five Year＂ Research Fund of Health Care of the PLA（Grant No.01MA111） and Innovation Fund of General Hospital of PLA （Grant No.06ZS13）.