Department of General and Abdominal Surgery, University Medicine of the Johannes Gutenberg-University, Mainz, Germany.
Colorectal Dis. 2011 Dec;13(12):1422-7. doi: 10.1111/j.1463-1318.2010.02510.x.
Intra-operative neuromonitoring is increasingly applied in several surgical disciplines and has been introduced to facilitate pelvic autonomic nerve preservation. Nevertheless, it has been considered a questionable tool for the minimization of risk, as the results are variable and might be misleading. The aim of the present experimental study was to develop an intra-operative neuromonitoring system with improved reliability for monitoring pelvic autonomic nerve function.
Fifteen pigs underwent low anterior rectal resection with pelvic autonomic nerve preservation. Intra-operative neuromonitoring was performed under autonomic nerve stimulation with observation of electromyographic signals of the internal anal sphincter and bladder manometry. As the internal anal sphincter frequency spectrum during stimulation was found to be mainly in the range of 5-20 Hz, intra-operative neuromonitoring signals were postoperatively processed by implementation of matching band pass filters.
In 10 preliminary experiments, signal processing was performed offline in the postoperative analysis. Of 163 stimulations intra-operatively assessed by the surgeon as positive responses, 135 (83%) were confirmed after signal processing. In the following five consecutive experiments intra-operative online signal processing was realized and demonstrated reliable intra-operative neuromonitoring signals of internal anal sphincter activity with significant increase during pelvic autonomic nerve stimulation [0.5 μV (interquartile range = 0.3-0.7) vs 4.8 μV (interquartile range = 2.5-7.5); P < 0.001].
Online signal processing of internal anal sphincter activity aids reliable identification of pelvic autonomic nerves with potential for improvement of intra-operative neuromonitoring in pelvic surgery.
术中神经监测在多个外科领域得到了越来越广泛的应用，并被引入以促进骨盆自主神经的保留。然而，它被认为是一种可疑的降低风险的工具，因为结果是可变的，可能具有误导性。本实验研究的目的是开发一种具有更高可靠性的术中神经监测系统，以监测骨盆自主神经功能。
15 头猪接受了保留骨盆自主神经的低位前直肠切除术。术中神经监测在自主神经刺激下进行，观察肛门内括约肌的肌电图信号和膀胱测压。由于刺激期间肛门内括约肌的频谱主要在 5-20 Hz 范围内，因此术后对术中神经监测信号进行了处理，实施了匹配的带通滤波器。
在 10 个初步实验中，信号处理是在术后分析中离线进行的。在由外科医生评估为阳性反应的 163 次术中刺激中，经信号处理后得到了 135 次（83%）的确认。在接下来的五个连续实验中，实现了术中在线信号处理，并展示了可靠的术中肛门内括约肌活动的神经监测信号，在骨盆自主神经刺激期间显著增加[0.5 μV（四分位距=0.3-0.7）与 4.8 μV（四分位距=2.5-7.5）；P<0.001]。
肛门内括约肌活动的在线信号处理有助于可靠地识别骨盆自主神经，可能改善骨盆手术中的术中神经监测。
