诱发电位量化监护在下腰椎滑脱复位内固定术中的应用

背景临床大量病例证实,下腰椎滑脱复位内固定术中满意的复位、融合及内固定,与患者术后症状体征及功能恢复程度并非一致.目的研究体感诱发电位(SEP)在下腰椎滑脱复位内固定术中监护的应用,对改善患者术后症状及提高脊柱功能的作用.设计随机对照研究.单位一所大学医院的脊柱外科病房.对象2000-06/2003-12暨南大学医学院第二附属医院(深圳市人民医院)脊柱外科收治的下腰椎滑脱症患者52例,男23例,女29例,年龄18～68岁.随机分为对照组20例和监测组32例.方法对照组利用节段性皮神经刺激体感诱发电位(SEP)技术对下腰椎滑脱复位内固定术前,术中监测和术后远期随访,对术后功能改善优良患者的术中电位变化情况进行回顾性研究,确定术中有效的监护指标,从而为监测组手术监护提供参考.主要观察指标①术后脊柱功能评定结果.②体感诱发电位潜伏期及波幅检测结果.结果以患者术前麻醉后SEP指标值为基础,术中监测电位指标变化表现形式①滑脱复位后,若潜伏期缩短10%～15%或波幅增加＞40%,提示愈后良好.②监测电位指标平稳,或潜伏期缩短＜10%,或波幅增加＜30%,可继续完成复位,术后可有部分神经根功能恢复和症状改善.③复位过程中,监测电位指标出现暂时性波动,可在15～20 min内恢复到基础电位,应在电位出现波动时停止复位.术后仍可有部分神经根功能恢复和症状改善.④术中监测电位若潜伏期延长＞5%,或波幅降低＞10%,或部分成分消失或波形离散,提示术后出现疼痛和运动障碍加重,术中应做必要调整.该方法术中监护指标改善与术后脊柱功能恢复状态符合率达93.75%.结论节段性皮神经刺激SEP是下腰椎滑脱复位内固定术中监护指导减压、复位、固定的客观而有效的方法.对改善神经根功能,恢复脊柱功能有重要价值.

Application of evoked potential quantification monitoring in the internal fixation for inferior lumbar spondylolisthesis

BACKGROUND: Many clinical cases have proved that the satisfactory reposition, fusion and internal fixation in the internal fixation for inferior lumbar spondylolisthesis are not consistent with the postoperative symptoms and physical signs, and functional restoration.OBJECTIVE: To investigate the application of somatosensory evoked potential(SEP) in the monitoring during internal fixation for inferior lumbar spondylolisthesis, and the effects of SEP monitoring on the improvement of postoperative symptoms and the spinal functions as well.DESIGN: A randomized controlled trial.SETTING: Inpatient department of spinal surgery, an affiliated hospital of a university. PARTICIPANTS: Fifty-two patients with inferior lumbar spomlylolisthesis including 23 male and 29 female cases aged between 18 and 68 years old were admitted by the Department of Spinal Surgery, Second Affiliated Hospital(Shenzhen People's Hospital) of Jinan University, from June 2000 to December 2003. All cases were randomly divided into control group(n = 20) and monitor group ( n = 32).METHODS: SEP induced by segmental stimulation in cutaneous nerve was used in the control group for preoperative and intraoperative monitoring, and postoperative follow up. The intraoperative potential changes in patients with excellent and good improvement in postoperative functions had been retrospectively investigated to confirm the effective indices for intraoperative monitoring, which thereby provided references for intraoperative monitoring in patients of monitor group.MAIN OUTCOME MEASURES: ① Evaluation of postoperative spinal function; ② SEP latency and amplitude.RESULTS: SEP values after postoperative anesthesia were set as basis.The manifestations of intraoperative potential alterations: ① If the latency reduced 10% -15% or the amplitude increases more than 40% after fixation, it suggested favorable prognosis; ② The potential indices were stable during monitoring, or the reduction of latency was less than 10%,or the increase of amplitude was less than 30%, the fixation could be continued, and partial functions of nerve root and symptoms could be improved after surgery; ③ During the surgery, if potential indices had transient lluctuation, which could be recovered to basic potential within 15 to 20 minutes, fixation should be stopped during the fluctuation. Still partial functions of nerve root and symptoms could be improved after surgery; ④If the intraoperative latency prolonged more than 5%, or amplitude reduced more than 10%, or part of the components disappeared, or the wave shape dispersed, it might suggest postoperative aggravation of pain and dyskinesia. So intraoperative adjustment was necessary. The coincident rate of the improvement of the indices of intraoperative monitoring and the improvement of postoperative spinal function reached 93.75%.CONCLUSION: SEP induced by segrmental stimulation in cutaneous nerve is an objective and effective method in the monitoring and instruction of decompression, reposition, fixation of internal fixation for inferior lumbar spondylolisthesis, which has important merits in the improvement of the function of nerve root and the restoration of spinal function.