前庭窗下缘与耳蜗底转骨内膜毗邻关系的解剖学研究及临床意义

Clinical significance and anatomical relationship between the inferior margin of oval window and the endosteum of basal cochlear turn

目的通过对前庭窗下缘与耳蜗底转骨内膜间毗邻关系的解剖测量，探索困难镫骨手术中前庭窗下方鼓岬磨钻、开窗的安全范围。方法14个成人颞骨标本，采用组织学切片的方法，在前庭窗下缘前、中、后的三个垂直切面上对前庭窗下缘与耳蜗底转骨内膜不同部位间的距离、骨内膜高度及对应的鼓岬厚度进行测量。结果前庭窗后端下方鼓岬最厚，平均约1．1mm，该处耳蜗骨内膜最深在，平均高度仅约0．2mm，但该处前庭窗下缘距离下方耳蜗骨内膜仅0．3mm。结论磨除鼓岬部分骨质的相对安全部位是前庭窗后端下方，磨钻方向须保持向外下。

Objective To investigate the safety range of drilling and fenestration on promontory inferior to the oval window in difficult stapedectomy via anatomical study of the relationship between the inferior margin of oval window and the endosteum of basal cochlear turn. Methods By means of histological sections, the distances between the inferior margin of oval window and different locations of endosteum of basal cochlear turn, the corresponding height of the projecting endosteum and the thickness of promontory bone, on three vertical sections through the anterior, posterior and midpoint of the inferior edge of oval window were measured respectively. Results The promontory bone inferior to the posterior point of the oval window was thickest, with an average thickness of about 1.1 mm. The endosteum of basal turn at this portion was lowest, with an average height of O. 2 mm. Furthermore, the shortest distance here between the inferior edge of oval window and the endosteum could be no more than 0. 3 mm. Conclusion Relatively safe location of drilling on promontory should be selected on promontory inferior to the posterior point of the oval window, with the direction of drilling outward and downward.