听神经瘤术中面神经最大阈上刺激的波幅变化与术后早期面神经功能的关系及其影响因素

Relationship and influencing factors between the amplitude change of supramaximal facial nerve stimulation during acoustic neuroma removal and facial function outcome

目的探讨听神经瘤患者术中肿瘤切除前后面神经脑干处最大阈上刺激的波幅变化与术后早期面神经功能的关系，并分析其影响因素。方法回顾性分析34例听神经瘤患者的临床资料。采用SPSS17．0软件对术中肿瘤切除前后面神经脑干处最大阈上刺激的波幅变化与术后早期面神经功能的关系进行相关分析，并对肿瘤大小、囊性变情况、手术径路、面神经走行情况、肿瘤粘连情况等进行多因素分析。结果34例患者均顺利完成手术，无术中及术后并发症，面神经解剖学保留完整。术后2周时面神经功能House—Brackmann（HB）分级Ⅰ级5例，Ⅱ级13例，Ⅲ级11例，Ⅳ级5例。肿瘤切除前后面神经脑干处最大阈上刺激的波幅变化为12．9％～100．0％，平均（63．9±25．7）％。若术中波幅下降〉70％，则面神经功能损伤多较严重（HB1V级及以上）。术中最大阂上刺激的波幅变化在不同面神经功能组间比较，差异具有统计学意义（F：7．585，P=0．001），两两比较后发现仅HBI级组和HBⅡ级组的波幅变化差异无统计学意义（P=0．736），其他各组间差异均具有统计学意义（P值均〈0．05）。相关分析提示术中波幅变化比值与肿瘤囊性变存在强负相关（r=-0．635），与肿瘤神经粘连程度存在中度负相关（r=-0．455），而与肿瘤大小存在弱负相关（r=-0．292），手术径路及面神经走行与肿瘤切除后的波幅改变无明显相关性。结论听神经瘤患者术中肿瘤切除前后面神经最大阈上刺激的波幅改变情况可预判术后早期面神经功能，能够为面神经损伤的早期治疗提供参考依据。

Objective To investigate the relationship between the amplitude change of supramaximal facial nerve stinmlation during acoustic neuroma removal and facial function outcome, and discuss its influencing factors. Methods Retrospective study of 34 acoustic neuroma patients. Intraoperative amplitude by supramaximal stimulation, facial function outcome, tumor size, surgical approach, facial nerve course pattern, and tumor cystic status, as well as tumor adhesion degree were collected and analyzed by SPSS 17. 0. Results Acoustic neurnomas were removed in all 34 patients without intra- and postoperative complications, the facial nerve were all anatomically preserved. Two weeks later, 5 cases showed facial function HB Grade Ⅰ , 13 HB Ⅱ , 11 HB Ⅲ and 5 HB Ⅳ. The amplitude changes under supramaximal stimulation after tumor removal were 12. 9% -100% , average （ 63.9 ± 25.7 ） %. The facial function outcomes were poor （ HB IV ） in the cases whose intraoperative amplitude decreases were more than 70%. Different postoperative facial function group showed significantly different intraoperative amplitude changes （F = 7. 585,P = 0. 001 ）, except HB I group and HB 11 group. The existence of cystic degeneration showed strong correlation （ r = - 0. 635 ） to the amplitude changes, the level of tumor adhesion showed moderately negative correlation （ r = - 0. 455 ） , and tumor size showed weak negative correlation （r =-0. 292）, surgical approach and the facial nerve course pattern were not statistically relevant. Conclusions The amplitude change of facial nerve supramaxial stimulation can predict the postoperative facial function. The amplitude change is valuable for early treatment of facial nerve damage.