Tce-MEP对大鼠坐骨神经显微吻合术后的评估价值

Evaluation value of Tce-MEP in rat sciatic nerve after microsurgical anastomosis

目的探讨经颅电刺激运动诱发电位(Tce-MEP)对大鼠坐骨神经断裂损伤动物模型显微外科手术吻合术后的评估价值。方法将18只大鼠随机分为对照组(Sham组)、坐骨神经断裂损伤吻合手术组(Model组)、坐骨神经断裂损伤不吻合组(SNI组),每组各6只。Sham组只行坐骨神经分离术不损伤坐骨神经,SNI组和Model组大鼠在距梨状肌下缘1 cm处切断坐骨神经干,Model组立即行神经外膜端端吻合,SNI组不吻合。各组均记录大鼠术前及术后第2天、第7天、第14天和第30天的Tce-MEP潜伏期及波幅;分别在术前及术后第2天、第7天、第14天和第30天行大鼠Bsso-Beattie-Bresnahan(BBB)运动功能评分;各组均在术后第30天取材,采用苏木精-伊红(HE)染色观察大鼠坐骨神经的组织形态学改变,采用透射电镜观察其坐骨神经组织超微结构变化。结果Model组和SNI组所有大鼠坐骨神经剪断后均出现Tce-MEP波形变化,Model组吻合术前表现为潜伏期延长及波幅降低(P<0.05),术后不同时间段复测波形均有所恢复。Model组和SNI组术后各时间点均较术前BBB评分降低(P<0.05)。HE染色法和透射电镜显示,Model组坐骨神经远端脱髓鞘现象较SNI组好转。结论显微外科吻合手术可以促进大鼠坐骨神经断裂损伤的神经功能修复,且可以减轻神经损伤远端的脱髓鞘改变;Tce-MEP可以连续客观地评估大鼠坐骨神经断裂损伤修复后不同时间点的神经传导功能恢复情况。

Objective To explore the evaluation value of transcranial electrical motor evoked potential(Tce-MEP)in rat sciatic nerve rupture injury after microsurgical anastomosis.Methods A total of 18 rats were randomly divided into a control group(Sham group),model group(a sciatic nerve fracture injury+anastomosis)and SNI group(a sciatic nerve fracture injury),with 6 rats in each group.Sham group underwent sciatic nerve dissection without damaging the sciatic nerve,while the sciatic nerve trunks in SNI and Model groups were cut at a distance of 1 cm from the low edge of the piriformis muscle.Model group was given end to end anastomosis of the outer nerve membrane,while SNI group was not given anastomosis.Tce-MEP latency and wave amplitude of the rats were recorded before surgery and on days 2 nd,7 th,14 th and 30 th after surgery.Bsso Beattie Bresnahan(BBB)was perform to score rat motor function before surgery and on the days 2 nd,7 th,14 th and 30 th after surgery.Samples were taken from each group on the 30 th day after the surgery,and hematoxylin-eosin(HE)staining was conducted to observe the morphological changes of rat sciatic nerve tissues.Ultrastructural changes of rat sciatic nerve tissues were observed by transmission electron microscopy.Results All rats in model and SNI groups had Tce-MEP waveform changes after cutting sciatic nerves.Model group showed prolonged latency and decreased amplitude before anastomosis(P<0.05),and re-examinations at different periods showed that the waveforms were recovered after surgery.BBB scores of Model and SNI groups at each time points after surgery were lower than those of before surgery(P<0.05).HE staining and transmission electron microscopy showed that the demyelination of the distal sciatic nerves was improved in Model group when compared to SNI group.Conclusion Microsurgical anastomosis may promote the repair of nerve function and reduce demyelination at the distal end of sciatic nerve injury.Tce-MEP can be used to continuously and objectively evaluate the recovery of nerve conduction function at different times after the repair of sciatic nerve injury.