内镜辅助显微血管减压术治疗微血管压迫综合征性耳鸣

Microvascular decompression for subjective tinnitus induced by microvascular compression syndrome with endoscope assisting

目的：探讨乙状窦后径路显微镜下内镜辅助血管减压术治疗MRI薄层扫描诊断的血管压迫综合征性耳鸣的手术方法、临床效果及应用价值。方法：对临床3例经MRI小脑-桥脑角薄层扫描而诊断的微血管压迫综合征性耳鸣患者，采用内镜辅助显微血管减压术，隔离和消除小脑前下动脉及其分支对听神经的密切接触与压迫。术前分别进行耳鸣频率和响度的客观测试，手术前后进行纯音测听、耳蜗电图、听性脑干诱发电位（ABR）、前庭功能、面神经功能等项测试和检查。结果：术后3例患者均自觉耳鸣消失，术前耳鸣频率范围为2～4kHz，响度为平均听闽上2．5～3．75dB，手术前后主客观听闻无明显变化；术前ABR显示中等强度刺激声测试之曲线波型重复性较差，术后I-V波的波间潜伏期较术前缩短；1例患者术前的前庭功能检查发现存在向患侧优势偏向，术后消失。手术前后面神经功能正常，未出现任何术中和术后并发症。术后随诊3～6个月未见耳鸣复发。结论：MRI小脑-桥脑角薄层扫描是一种极为高效、准确的检查和诊断微血管压迫综合征性耳鸣的手段，对于诊断明确的该病患者，内镜辅助行显微血管减压术是一项极为有价值的治疗技术和方法，较之以往经典的手术显微镜下操作更为安全、清楚，创伤亦有所减小，并且未出现使用内镜而造成手术时间延长或相关并发症等情况，具有推广应用价值。

Objective To research into the minimal invasive technique and significance of endoscope assisted operation of microvascular decompression via retrosigmoid approach for subjective tinnitus induced by microvascular comprssion syndrome on patients diagnosed by MRI lamella-scan preoperatively. Methods 3 patients underwent the microvascular decompression via retrosigmoid approach with endoscope assisting during operation. After mobilization and elevation of the vein, Teflon felt was placed between the mobilized vessels and vestibulocochlear nerve complex under endoscopy. Introperative ABR and the facial nerve integrity monitoring were performed. All of patients were examined of pure tone auditory test, ABR test, EcochG, vestibular function （ electronystagmography）, facial nerve function, and observed of clinical situation（ including complications and equilibrium function and so on） before and after operation. Results All 3 patients felt tinnitus disappearring 3 to 6 months after operation. Before operation ,2 patients＇ frequency of tinnitus were 2 kHz to 4 kHz,and sound-volume were 2.5 dB to 3.75 dB beyond average hearing threshold,and another patient＇s tinnitus could objectively be measured. Compared with preoperation, postoperative average hearing threshold and facial nerve function had no any remarkable difference, the latent period of I-V wave were prominently shortened, and no complications occurred. The predominance deflected to the diseased-side was found in one patient and it subsidised after surgery. Conclusion MRI lamella-scan at cerebellopontine angle and internal auditory canal is a method of exactly diagnosing tinnitus induced by microvascular compression syndrome. These patients could effectually treated with microvascular decompression. During endoscopic assisted operration is a safe and a minimal invasive technique, which doesn＇t bring about any complication and prolongation of operating-time.