中文摘要：

目的：报告开放式乳突根治术后伴重度或极重度耳聋患者人工耳蜗植入的手术方法及术后听觉康复效果。方法收集自2014年1月-2015年6月于我科行人工耳蜗植入的5例开放式乳突根治术后伴极重度耳聋患者，对其手术方法进行分析，并于术后6个月对患者行CAP、SIR、MAIS、M-LNT等听觉康复测试。5例患者均经圆窗入路植入电极，于外耳道下壁与面神经嵴交界处磨出骨槽放置蜗外电极，以骨粉及颞肌筋膜覆盖保护。结果5例患者顺利植入全部电极。术中发现上鼓室胆脂瘤1例，鼓阶部分骨化3例。术后30天开机，患者听性反应明确。术后随访第6个月，4例患者（1例失访）对听觉康复效果满意，SIR、MAIS均满分，除1例患者外，CAP得分均≥8分，双难词表M-LNT得分均≥55%。目前3例患者随访超过1年，1例患者随访6个月，均未出现电极裸露、移位，术腔感染、面瘫、味觉丧失及胆脂瘤复发等并发症。结论对于已行开放式乳突根治术的极重度耳聋患者，在干耳情况下尽早行人工耳蜗植入术，术后听觉康复效果满意。但因原解剖结构破坏，操作者需经验丰富，以免找不到圆窗或术中发现鼓阶骨化，而导致植入失败。

英文摘要：

Objective To report methods and hearing outcomes of cochlear implantation in patients with severe or pro-found hearing loss who had received canal wall down mastoidectomy. Methods Five patients who had undergone canal wall down mastoidectomy from January 2014 to June 2015 received cochlear implantation through the round window with the bone groove made at the junction of inferior external auditory canal wall and facial ridge and the outer electrodes covered with bone paste and temporalis fascia. Surgical techniques and hearing rehabilitation outcomes at 6 months, such as CAP, SIR, MAIS and M-LNT, were reviewed. Results Implantation was successful in all 5 cases. Intraoperative findings included attic cholesteatoma （n=1） and ossified tissues in scala tympani （n=3）. Patients reported clear auditory perception upon co-chlear implant switch-on at 30 days after operation. At 12 months （n=3） or 6 months （n=1） follow up, patients expressed sat-isfaction with the treatment. One case was lost to follow up. No complication occurred. Conclusion Patients with severe or profound hearing loss who have received canal wall down mastoidectomy can still be candidates for cochlear implantation once their ears stopped discharging, with the opportunity to achieve satisfactory hearing outcomes. Because of likely distort-ed anatomy, a skilled surgeon may be needed to avoid electrode implantation failure due to possible difficulties to find round window or identifying ossified scale tympani during surgery.