冷冻保存后不同直径异体神经移植的实验研究

Experimental study on allograft of cryopreserved rat peripheral nerve with different diameter

目的探讨经液态氮冷冻贮存后,不同直径同种异体神经移植的神经再生情况。方法取40只Wistar大鼠,雌雄不限,取10只鼠分别切取正中神经、桡神经及坐骨神经,放于-196℃液态氮贮存3周备用;其余30只鼠随机分为A、B、C 3组,均造成右侧胫神经8 mm的神经缺损模型,分别植入不同直径异体神经。A组:粗直径同种异体神经移植组;B组:等直径同种异体神经移植组;C组:细直径同种异体神经移植组。术后2、4周分别进行大体手术显微镜下观察、病理组织学及电生理学检查。结果电生理学检查:2周时,传导速度(CV)及波幅(Amp)经统计学分析,A、B、C 3组之间无显著性差异(P>0.05);4周时,CV及Amp经统计学分析,3组之间存在显著性差异(P<0.05),并且C组明显优于A组。病理组织学检查:2周时,3组均见明显髓鞘、轴突崩解和空泡变性,基底膜管完整清晰,外周见较多新生血管及巨噬细胞、淋巴细胞浸润;4周时,各组吞噬现象消失,并见较多新生神经轴突,其中C组的再生轴突数量和直径均优于其余2组;结论不同直径同种异体神经移植,对神经再生效果有明显影响,其中细直径移植组神经再生效果最佳。

Objective To study the condition of neuroregeneration after allograft of cold-preserved nerve with different diameter. Methods Forty wistar rats were chosen for the experiment. Median nerve, radial nerve and sciatic nerve were harvested to be cold-preserved（ the holding temperature of - 196℃） for 3 weeks from l0 rats, the rest which were made a eight-millimeter nerve defect on the right tibal nerve were randomly divided into 3 groups： thick diameter nerve allograft （group A） , equal diameter nerve allograft（ group B）, thin diameter nerve allograft （group C ）. The prepared grafts were transplanted to bridge the gap of tibal nerve defect. At the 2th and 4th week after transplantation, the specimens were observed under microscrope, and the nerve regeneration were evaluated by histological and electro-physiological techniques. Results Post-transplantation： At 2th week： according to statistic-study on CV＆AMP, there was no significant difference among the thick, the equal and the thin diameter group （P 〉 0.05 ）. At the 4th week： the differences among the three groups were significant. Moreover, group C was better than group A. At the 2th, 4th week respectively, nerve grafts were harvested for histomorphometric analysis, which demonstrated that axon and myelin were comprehensively breaked down and large quantity of macrophages, lymphocytes were infiltrated in each group. However, at the 4th week, cellular infiltration disappeared and neuroregeneration diffused. Furthermore the numbers and diameters of regenerated nerve was the best in group C. Conclution After cryopreservation, the neuroregeneration effect of the different diameter nerve allograft was distinctly different, group C was superior to the rest groups.