低水平神经肌肉阻滞状态下听神经瘤切除术中面神经的保护

目的在低水平神经肌肉阻滞状态下进行听神经瘤切除术中面神经的保护。方法28例大、中型听神经瘤患者行听神经瘤切除术,术中应用AXONEpochXP神经电生理工作站,根据4个成串刺激(train of four stim-ulation,TOF)和脑电图(EEG)分别监测肌松程度和麻醉深度,在肿瘤切除过程中通过调节肌松药物和麻醉药物剂量使T4/T1维持在25%～50%,术中监测眼轮匝肌、口轮匝肌、咬肌和斜方肌自由描记肌电图和诱发肌电图,分别反应面神经、三叉神经和副神经功能。于术后1周和术后第6个月分别评估面神经功能。结果28例患者术中均成功探测到面神经走行,电刺激强度为0.1～0.3mA,术中无患者发生体动情况。术后面神经功能保留率良好,术后1周面神经House-Brackmann(H-B)功能分级为Ⅰ级者5例、Ⅱ级者13例,Ⅲ级者8例,Ⅳ级者2例;至术后6个月面神经H-B功能分级Ⅰ级者10例,Ⅱ级者12例,Ⅲ级者5例,Ⅳ级者1例。结论在听神经瘤手术过程中通过电生理监测对面神经进行保护,需要电生理、麻醉和手术医生的配合。在低水平神经肌肉接头阻滞状态下,完全可以达到确保手术安全进行及保护面神经功能的目的。

Facial Nerve Monitoring in Patients Under The Low Level Of Neuromuscular Blockade During Resection Of acoustic Neurinomas

Objective To perform facial nerve monitoring in patients under the low level of neuromuscular blockade during resection of acoustic neurinomas.Methods Twenty-eight patients with large,or medium acoustic neuroma underwent the surgery of acoustic neurinomas resection. During the operation,TOF and EEG monitoring were performed in order to detect the degree of muscle relaxation and the depth of anesthesia. Neuromuscular relaxation was maintained at T_4/T_1=25%～50% by adjusting doses of muscle relaxant and aneasthetic. Free-run EMG and Triggered EMG of orbicularis oris, orbicularis oculi, masseter and trapezius were recordered to monitor the function of the facial, trigeminal and accessory nerves, respectively. The function of the facial nerve was evaluated at first week and half year postoperatively according to House-brackmann classification.Results The facial never was successfully identified and mapped by neurominitoring in all 28 patients. successfully, tThe electrical stimulation was 0.1 mA-0.3 mA and no any involuntary body movement was observed in all patients ne of patients have moved during operation. The preservation of the facial nerve function following surgery was good. Five patients had a HB grade I, 13 a HB grade II, 8 a grade III and 2 a HB grade IV The facial nerve function was HB Grade Ⅰin 5 of 28 patients, HB GradeⅡ in 13, HB Grade Ⅲ in 8 and HB Grade Ⅳ in 2 immediately after operation. Six months after surgery, 10 casespatents showed demonstrated a HB GradeⅠof facial never function, 12 cases exhibited a slight palsy (HB Grade II) , and 5 cases exhibited a HB Grade III palsy and . Another 1 cases a exhibited severe palsy (HB Grade IV).Conclusions Facial nerve monitoring in patients under the low level of neuromuscular blockade can ensure the surgical safety and preserve the facial never function.