大型听神经瘤手术中面神经监测的效果观察

The study on intraoperative monitoring of cranial nerve in large acoustic neuroma

目的了解大型听神经瘤手术中连续面肌肌电图监测对术中、术后面神经解剖和功能保留的作用。方法根据Gormley颅内肿瘤分型方法,100例听神经瘤患者中肿瘤直径为4.0～4.9cm者82例,5.0～5.9cm者16例,直径≥6.0cm者2例。手术前采用House等面神经功能分级标准进行评估,Ⅰ级65例,Ⅱ级33例,Ⅲ级2例。采用经乙状窦后入路显微外科手术切除肿瘤,术中施行面肌肌电图监测和直接电刺激。结果100例中肿瘤全切除或近全切除者94例,大部分切除6例。2例肿瘤切除过程中切断面神经者均行Ⅰ期端-端吻合;2例面神经被切断1/2者行断端吻合。手术后2周面神经功能评估Ⅰ级30例,Ⅱ级50例,Ⅲ级10例,Ⅴ级10例;手术后1年随访面神经功能Ⅰ级76例,Ⅱ级14例,Ⅲ级7例,Ⅴ级3例。结论大型听神经瘤手术中采用面神经监测对面神经的解剖和功能保留有明显效果。

Objective： To studythe effectof continuous EMG monitoring of facial muscle on the neural anatomy and function reserving of facial nerve during and after operation. Methods A total of 100 patients with acoustic neuroma were enrolled in this study. According to Gormley＇s classification of intracranial tumor, in 100 patients the diameters of acoustic neuromas were 4.0-4.9 cm （82 cases）, 5.0-5.9 cm （16 cases） and ≥ 6.0 cm （2 cases）. Preoperative evaluation with House facial nerve function scale demonstrated there were Grade Ⅰ 65 cases, Grade Ⅱ 33 cases and Grade Ⅲ 2 cases. These patients were performed microsurgical resection of tumor via retrosigmoidal approach, direct electric stimulus and monitoring the facial nerve EMG during operation. Results In the 100 patients there were total or subtotal resection of tumor in 94 cases and more than half resection of tumor in 6 cases. The facial nerves were cut off during resection of tumors in 2 patients and then end to end anastomosis were performed at the same time. In another 2 patients their facial nerve were cut off about 1/2 then the breaking end anastomosis were performed. Postoperative two weeks, the evaluation of facial nerve function demonstrated that there were Grade Ⅰ 30 cases, Grade Ⅱ 50 cases, Grade Ⅲ 10 cases and Grade Ⅴ 10 cases. There were Grade Ⅰ 76 cases, Grade Ⅱ 14 cases, Grade Ⅲ 7 cases and Grade Ⅴ 3 cases in facial nerve function 1 year postoperative following up. Conclusion It is demonstrated the intraoperative monitoring of facial nerve function with EMG during surgical treatment of large size acoustic neuroma is significantly effective in anatomical and functional preserving for facial nerve.