人工耳蜗植入术的应用解剖学研究

目的探讨后鼓室入路人工耳蜗植入术的有关解剖,为人工耳蜗植入手术提供解剖学基础。方法取成人颞骨标本60侧(左、右各30侧),在放大6倍的手术显微镜下进行观察和测量,结果进行统计学处理。结果圆窗龛(窝)的形态大体分为2种类型:近圆形(52%)和近半圆形(48%)。圆窗龛下壁有一窦腔者占86.7%。岬下脚出现率为11.7%,岬小桥出现率为33.3%。颈静脉窝高位,窝顶达圆窗龛上缘者占11.7%,均未影响圆窗龛的形态。外耳道上棘至锥隆起、鼓索隆起、圆窗龛前唇(缘)、面神经管锥曲的距离分别是(18.02±1.21)mm、(15.22±1.32)mm、(20.09±1.20)mm、(14.96±2.03)mm。鼓索隆起至面神经管锥曲、锥隆起的距离分别是(3.33±0.42)mm、(3.79±0.56)mm。锥隆起向后至面神经管的距离平均为(3.58±0.47)mm。结论后鼓室进路即是通过面神经隐窝的进路,面神经隐窝大小各异,鼓索隆起至面神经管锥曲和至锥隆起的距离,可作为面神经隐窝的宽度。人工耳蜗植入术经面神经隐窝入路较理想,距圆窗龛较近,有利于电极插入。该入路靠近面神经管,手术操作时应注意保护面神经。圆窗龛前唇遮盖圆窗膜,手术时必须磨去前唇暴露圆窗膜。

Applied anatomy of cochlear implantation

Objective To provide the anatomic data for cochlear implantation through posterior tympanum approach. Methods On 60 sides of adult temporal bone specimens, the related anatomic structures were observed and measured under the surgical microscope. Results Round window niche generally can be distinguished as two shapes: the approximate round shape (52%) and approximate halfround shape (48%). The appearance rate of subiculum, ponticulus, the inferior wall of round window niche with a sinus, and the tip of jugular fossa reaching the superior border of round window niche were 11.7%, 33.3%, 86.7%, 11.7% respectively. The distances from suprameatal spine to pyramidal eminence, chordal eminence, the anterior lip of round window niche, pyramid segment of facial canal were (18.02±1.21) mm, (15.22±1.32) mm, (20.09±1.20) mm, (14.96±2.03 ) mm respectively. The distances from chordal eminence to pyramid segment of facial canal, pyramidal eminence were(3.33±0.42) mm, (3.79±0.56) mm respectively. The distance from pyramid eminence to facial canal was (3.58±0.47) mm. Conclusions Posterior tympanum approach is a approach through facial recess. Though facial recess has its various size, the distances from chordal eminence to pyramid segment of facial canal or pyramid eminence can be considered as its width. Facial recess approach for cochlear implantation is reasonable because it is close to round window niche for electrode insertion easy. This approach is near facial canal, so facial nerve should be protected, and the anterior lip of round window niche, which cover round window membrane, should be removed to expose round windowmembrane during the operation.