Rizvi S S, Goyal R N
Bay Medical Center, Department of Otolaryngology, Bay City, Michigan, USA.
Am J Otol. 1999 Mar;20(2):249-52.
Since 1991, three separate reports have shown how hearing may be salvaged after translabyrinthine excision of small acoustic tumors. The authors submit yet another report of a complete translabyrinthine excision of a 1.4-cm intracanalicular acoustic tumor with modest hearing preservation. An attempt is made to retrace the steps of the operation and recognize and discuss what particular events may have safeguarded the viability of the cochlea. With the availability of cochlear implantation, there should be added incentive to preserve the cochlear neurones if hair cells cannot be saved.
The study design was a retrospective case review.
The study was conducted at a primary care hospital.
Therapeutic and rehabilitative measures were performed.
Hearing preservation was measured.
A 55-year-old woman presented with a left-sided hearing loss and a 1.4-cm left acoustic tumor completely filling the internal auditory canal (speech reception threshold [SRT] 30 dB, discrimination [Pb] 28%). A successful translabyrinthine excision of the tumor was performed in November 1995. A 1-year postoperative audiogram showed a mixed hearing loss in the left ear with SRT 85 dB and Pb 0%. Average pure-tone threshold for 500 Hz, 1 kHz, and 3 kHz was 50 dB and aided SRT 40 dB with Pb 64%. Postoperative magnetic resonance imaging confirmed complete excision of the tumor.
An exceptional case of hearing preservation after translabyrinthine excision of a small acoustic tumor illustrates how it may be possible to preserve cochlear hair cells and neurones simultaneously in certain selected cases. A review of the surgical events shows the value of sealing the cochlear duct with bone wax, selectively removing the vestibular nerves with the tumor by sharp dissection, and safeguarding the meatal segment of the anterior inferior cerebellar artery by a limited dural incision.
自1991年以来，已有三份独立报告展示了在经迷路入路切除小型听神经瘤后听力如何得以挽救。作者现提交另一例报告，内容为对一例1.4厘米内耳道听神经瘤进行完全经迷路入路切除并实现适度听力保留。本文尝试回顾手术步骤，识别并讨论哪些特定事件可能保障了耳蜗的存活能力。鉴于人工耳蜗植入技术的应用，如果无法挽救毛细胞，那么保留耳蜗神经元就更具激励意义。
本研究设计为回顾性病例分析。
研究在一家基层医院开展。
实施了治疗和康复措施。
测量听力保留情况。
一名55岁女性，左侧听力丧失，左侧有一个1.4厘米的听神经瘤，完全充满内耳道（言语接受阈[SRT] 30分贝，辨别率[Pb] 28%）。1995年11月成功进行了经迷路入路肿瘤切除术。术后1年的听力图显示左耳为混合性听力损失，SRT为85分贝，Pb为0%。500赫兹、1千赫和3千赫的平均纯音阈值为50分贝，助听后SRT为40分贝，Pb为64%。术后磁共振成像证实肿瘤已完全切除。
一例小型听神经瘤经迷路入路切除术后听力保留的特殊病例表明，在某些特定病例中，有可能同时保留耳蜗毛细胞和神经元。回顾手术过程发现，用骨蜡封闭耳蜗管、通过锐性分离选择性地将前庭神经与肿瘤一并切除以及通过有限的硬脑膜切口保护小脑前下动脉的耳道段具有重要意义。
