显微镜下双极电凝法应用于腰椎后路手术神经根周围止血的实验观察

Experimental study of bipolar electrocoagulation under microscope for peripheral hemostasis of nerve root in posterior lumbar surgery

目的在山羊腰椎后路手术模型中,探讨应用显微镜辅助下双极电凝法行椎管内神经根周围静脉丛止血的可行性、有效性及安全性,并探讨其合适的工作功率、止血距离。方法选取2只成年山羊为实验对象,模拟实施腰椎后路手术,暴露腰1~7水平硬膜和双侧神经根,分为实验组和阴性对照组。实验组:在显微镜下,用双极电凝在神经根周围做止血操作,选择5、15、25 W三种输出功率;阴性对照组:暴露神经根后不进行任何操作。术中行腰1~7神经根电生理检查电凝后神经根传导速度的变化,再取出该段神经根组织,进行病理切片HE染色了解神经根纤维组织的结构变化。结果动物实验过程顺利,显微镜辅助下能清楚显露山羊腰椎各节段神经根,术中见双极电凝强度为15 W和25 W局部静脉丛止血效果明显较5 W更好,术中电生理检测结果提示25 W电凝后神经根的传导速度与5 W组、15 W组、阴性对照组差异有统计学意义(P<0.01),且HE染色提示神经外膜结构损伤明显。结论显微镜辅助下显露椎管内静脉丛更清晰,在距离神经根1 mm处应用强度为15 W的双极电凝进行止血安全有效。

Objective To explore the feasibility, efficacy and safety of microscopically assisted bipolar electrocoagulation for the hemostasis of venous plexus around the nerve root in the spinal canal in the model of posterior lumbar spine operation in goats and discuss the appropriate working power and the distance for hemostasis. Methods Two adult goats were selected as experimental objects for the simulation of lumbar posterior operation. The epidural and bilateral nerve roots at Level 1-7 of the waist were exposed, which were divided into Experimental Group and Negative Control Group. Experimental Group： the bipolar electrocoagulation around nerve root was used to do hemostatic operation under microscope, and three levels of output power at 5, 15 and 25 W were selected; Negative Control Group： no operation was carried out after exposure of nerve root. During the operation, the changes of nerve root conduction velocity after electrocoagulation were examined, and then the nerve root tissue was taken out, and the structure of nerve root fiber tissue was studied by HE staining in pathological slices. Results The animal experiment was successful, and the nerve roots of the lumbar vertebrae of goats could be clearly exposed under microscope. The hemostatic effect of local venous plexus at 15 W and 25 W during operation was better than that at 5 W. The electrophysiological test results showed that the conduction velocity of the nerve root after 25 w electrocoagulation was significantly different from that of the 5 W Group and the 15 W Group as well as the Negative Control Group（P〈0.01）. HE staining showed that the damage to the outer membrane structure of nerve was obvious. Conclusion Microscopic exposure to the intraspinal venous plexus is more clear. It is safe and effective to use bipolar electrocoagulation at a distance of 1 mm from the nerve root at 15 W.