微波热凝对神经病理性疼痛大鼠机械痛敏及伊文氏蓝渗出的影响

Effect of microwave coagulation on mechanical allodynia and leakage of Evans blue in rats with neuropathic pain

目的 通过对大鼠神经病理性疼痛模型受损神经行不同温度微波热凝,观察大鼠患肢机械痛敏及阈上热刺激作用下伊文氏蓝渗出情况,探讨微波热凝对神经病理性疼痛的疗效、治疗的适宜温度及相关参数并分析其机理. 方法 42只大鼠建立坐骨神经分支选择性结扎切断模型后按随机数字表法分为3组,即微波42 ℃组、微波60 ℃组（功率皆为60W）和对照组（只插入微波热凝针但不加热）,每组14只.分别在治疗前1 d,治疗后1、2、4、6周测定大鼠患肢50%缩足阈值,治疗后2周在阈上热刺激作用下观察患肢足底伊文氏蓝渗出情况. 结果 对照组、微波42℃组、微波60 ℃组大鼠患肢50%缩足阈值在治疗前1 d比较差异无统计学意义（P＞0.05）.治疗后1、2、4、6周时与对照组、微波42 ℃组比较,微波60 ℃组大鼠患肢50%缩足阈值明显上升,比较差异有统计学意义（P＜0.05）.对照组、微波42 ℃及微波60℃组大鼠在阈上热刺激作用下伊文氏蓝渗出浓度分别为（14.8±2.88）g/g、（9.96±1.01）g/g、（7.41±1.37）g/g,与对照组比较,微波42℃组、微波60 ℃组大鼠伊文氏蓝渗出浓度差异有统计学意义（P＜0.05）. 结论 微波热凝治疗能有效缓解坐骨神经受损所致神经病理性疼痛大鼠的机械痛敏,以60℃为宜.微波热凝神经减轻神经病理性疼痛的炎症反应可能是其缓解疼痛的机制之一.

Objective To observe the mechanical allodynia of affected extremity and the leakage of Evans blue when performing thermal stimulation on the threshold, and explore the efficacy of microwave on rats models of neuropathic pain and the optimum temperature and other ideal parameters for this treatment by performing microwave coagulation treatment under different temperatures to them.Methods Forty-two SD rats were induced the models of spared nerve injury （SNI） on sciatic nerves,then were equally randomized into 3 groups： control group （only inserting microwave coagulation needle but not heating）, 42℃ microwave coagulation treatment group and 60℃ microwave coagulation treatment group （n=14）. The 50% paw withdrawal threshold of the affected extremity was measured 1 d before and 1, 2, 4, and 6 weeks after treatment. The leakage of Evans blue in injured tissue of the affected extremity when performing thermal stimulation on the threshold was observed 2 weeks after treatment and compared between each 2 groups. Results The 50% paw withdrawal threshold was stable in control group, 42℃ microwave coagulation treatment group and 60℃ microwave coagulation treatment group 1 d before treatment; no significant differences were noted between each 2 groups （P〉0.05）. The 50% paw withdrawal threshold of 60℃ microwave coagulation treatment group 1, 2, 4, 6weeks after treatment was significantly increased as compared with that in the control group and 42℃microwave coagulation treatment group （P〈0.05）. The concentrations of leakage of Evans blue in the 42℃ microwave coagulation treatment group （[9.96±1.01] g/g） and 60℃ microwave coagulation treatment group （[7.41±1.37] g/g） were significantiy decreased as compared with those in the control group （[14.8±2.88] g/g, P〈0.05）. Conclusion Microwave coagulation can improve the mechanical hyperalgesia of in rats with neuropathic pain induced by SNI, and 60℃ is the proper temperature.Inflammation is inhibited by microwave coagulation and this might be one of the mechanisms to alleviate the pain.