Use of intraoperative electrophysiological monitoring in surgery for intraspinal tumors

English Keywords:Intraspinal tumors  Operation  Neurophysiological monitoring

English Abstract:

  【Abstract】 Objectives: To investigate the use of intraoperative electrophysiological monitoring in surgery for intraspinal tumors. Methods: 358 cases suffering from intraspinal tumors treated surgically from October 2000 to October 2010 were reviewed retrospectively. There were 234 cases of extramedullary intradural tumor and 124 cases of intramedullary tumor. All patients underwent electromyography(EMG) and somatosensory evoked potential(SEP) test of involved segments, which were used for comparement. Neural electricity physician was responsible for electrical monitoring during the operation, and SEP was used for monitoring spinal cord function, which was used to determine the range of defect resection. All tumors were removed microscopically under intraoperative neurophysiological monitoring. Results: Spontaneous EMG of 358 cases in intraoperative monitoring showed no abnormalities. EMG was used to determine the safe zone as well as the range of defect resection in 124 cases with intramedullary tumor. SEP showed abnormal in 36 cases during operation, of these, 29 cases had SEP amplitude decreasing of 20%-30%, which was detected by physician. After corresponsive intervention, SEP returned to preoperative levels 10-20min later. The SEP amplitude of 7 cases with intramedullary tumor decreased over 50%. After ceasing operation for 30mins, SEP recovered a little, and the operation continued. 358 tumors were removed microscopically under intraoperative neurophysiological monitoring, En bloc was performed in 292 cases including 234 extramedullary intradural tumor with normal intraoperative SEP. Of 124 intramedullary tumors, 58 tumors were removed completely(46.8%), while 66 intramedullary tumors were performed partial resection(53.2%). 7 cases suffering from SEP amplitude decreasing over 50% in operation had neurofunction deteriorated, of them, 6 cases had neurofunction recovered to preoperative level after corresponsive intervention 7-10 days later, while 1 case showed no improvement. Conclusions： The intraoperative neurophysiological monitoring can be used to guide the resection of tumor safely and effectively.