目的 探讨实验性内听动脉阻断与术后听力改变的关系及术中听觉监控的方法。方法 实验兔乙状窦后进路暴露小脑桥脑角，下压小脑暴露内听道及第Ⅷ神经复合体，分辨出内听动脉，予阻断不同时间，分别行蜗神经直接复合动作电位（DcAP）和畸变产物耳声发射记录（DPOAE）。结果 对照组DCAP Nl波潜伏期值无明显改变。内耳血供阻断10s和30s组在压迫开始后3min，DcAP Nl波潜伏期值均恢复为初始值。内耳血供阻断lmin组在压迫开始后3h，DCAP Nl波潜伏期值未恢复为初始值。假手术组I）POAE幅值无明显改变。内耳血供阻断10s、30s对DPOAE幅值无影响，内耳血供阻断1min使得DPOAE幅值下降。结论 兔内耳血供阻断lmin可能造成兔听觉不可逆损伤。DcAP、DPOAE能有效、持续地监控内耳血供阻断，是耳神经外科手术中实用的听觉监测手段。

目的 探讨听神经瘤分期方法及其与手术效果的关系。方法 回顾分析1999-2003年收治的109例听神经瘤病例按肿瘤大小分为1-5期，3例采用观察方法，106例分别采用扩大迷路进路、乙状窦后进路及颅中窝进路等手术治疗，根据肿瘤切除程度、面神经功能保留程度、听力保留程度等评估手术结果。结果 肿瘤全切率为95%（101/106），面神经保留率96%（102/106），迷路进路或扩大迷路进路患者面神经功能优良率（1-2级）为56%，可接受率（1-4）级为86%；听力保存率为42%。结论 听神经瘤的统一分期可以帮助选择治疗方案、评估手术效果，对临床治疗工作有重要指导意义。

Objective: the authors reviewed the clinical manifestations and the surgical outcomes in a series of young patients who underwent removal of large acoustic neuromas via the translabyrinthine approach. Methods: 40 young adults who underwent a translabyrinthine removal of acoustic neuromas 3cm or greater in size were analyzed. The patient's age ranged from 17 to 30 years. The mean size of tumor was 4.25cm. Results: the primary symptoms are similar to those in adult but usually less intense. The average interval time between the primary symptom and the diagnosis was 17 months. A high percentage of preoperative normal hearing (35%) and good facial function (100%) were noted. Translabyrinthine approach was used in all cases. Total removal was realised in 39 patients (97.5%). The facial nerve was anatomically preserved in 37 patients (92.5%). Twenty-six patients (65%) had a good facial function (House-Brackmann grade I or II) immediately or at 1 month after surgery, 11 patients (28%) achieved grade III or IV. Three patients underwent an immediate nerve repair after tumor removal. All of them recovered to grade III or IV 1 year after surgery. Postoperative complications were minimal. Conclusions: young adults may have a rapid growth rate but usually have minimal symptoms even with a large acoustic neuroma. The translabyrinthine approach has been used successfully in removal of large acoustic tumors of young patients, with the good result of facial nerve preservation and long-term tumor control.

Objective: To investigate the surgical techniques and speech performance of multichannel auditory brainstem implant ABI in patients with bilateral acoustic neuromas neurofibromatosis type 2. Methods The nucleus 21 channel auditory brainstem implant was implanted into the lateral recess of the foruth ventricle through the translabyrinthine approach in 7 patients after removal of the tumor. The accurate placement of electrode array was ensured by the electromyogram monitoring of the 7th and 9th nerves and the electrically evoked auditory brainstem responese EABR. Initial switch-on occurred six weeks postoperatively. Speech evaluation was performed every 3 months for the first year and annually thereafter. Results During the surgery the lateral reccess could be found and the typical EABR could in 6 cases. They later reported a significant benefit from the device. Two of the cases have achieved fuctional open-sel speech understanding. In contrast one patient with no EABR because of difficulty of the anatomic location during the surgery had no sensations postoperatively. Conclusion The multichannel ABIcould effectively restore auditory sensations in patients deafened by bilateral acoustic neuromas. The accurate location of the cochlear nucleus complex during surgery was the key factor for the success of the operation.