Clinical research on 46 cases of microoperation for acoustic neurinomas under the F wave assisted electrophysiological monitoring intraoperatively / 肿瘤研究与临床

ABSTRACT

ObjectiveTo study the methods of how to protect facial nerve function following complete resection of acoustic neurinomas and the value of the techniques of F wave assisted electrophysiological monitoring intraoperatively.Methods Retrospectivelysummarizing theresultsof combining three electrophysiological monitoring techniques such as nasal muscle F wave recording,online EMG and triggered EMG to monitor 46 cases of microoperations for acoustic neurinomas intraoperatively during the period of Feb.2004 to Dec. 2008. Correlating every intraoperative monitoring index with their follow-up results of facial nerve function 1 day and 6 months after their operations.The tendency of the two continuous monitoring techniques between nasal F wave recording and online EMG of facial muscles has also been studied in this paper. Results Among 46 cases of acoustic neurinomas, 45(97.83 %) tumors have been totally resected, and 1 (2.17 %) tumor subtotally resected,lcase (2.17 %)died after operation,and 2ases occurred the leakage of cerebrospinal fluid(CSF) which have been cured through conservative treatment. The whole anatomic protection rate of facial nerve is 97.83 %,and their functional protection rates 6 months after operation areHB Ⅰ - Ⅱ,75.56 %;Ⅲ-Ⅳ,22.22 % and Ⅴ-Ⅵ,2.22 %.The completely accordant rate between the intraoperative findings of nasal F wave recording and online EMG is 52.17 %, partially accordant rate is 45.65 %, and totally opposite rate is 2.17 % (x2 趋势= 6.113, P ＜0.05). The intraoperative monitoring indexes in nasal muscle F wave recording are correlated well with the facial nerve function in the 6th month' s follow-up (κ=0.429, P ＜0.001).In triggered EMG monitoring after tumors being resected,the stimulus threshold ratio and maximum amplitude ratio of facial nerve between leaving brain stem part and inner acoustic porus part are also correlated well with the facial nerve function 6 months after operation(κ=0.576, P ＜0.001; κ=0.595, P ＜0.001). ConclusionNasal muscle F wa recording cooperated well with online EMG and triggered EMG intraoperatively and correlates well with the postoperative facial nerve function, so they should be routinely applied together intraoperatively.