经岩骨入路手术中迷路保护的显微解剖学基础

目的 为经岩骨入路手术中保护迷路提供显微解剖学资料。方法 模拟幕上下联合经岩骨入路的手术操作，在手术显微镜下对１０具（２０侧）福尔马林固定的成人带颈头颅标本进行解剖，并观测骨迷路及其与重要结构间的解剖关系。结果 骨迷路为一块包绕膜迷路的质地致密、色泽亮丽的骨质，并构成乳突气房的内侧边界。磨削骨半规管透过菲薄的骨质显示暗蓝色的膜半规管即为“蓝线”。测量骨迷路与周围结构的距离有较大的个体差异，其中后半

Microsurgical anatomy of the protection of the labyrinth with the transpetrosal approach

Objective　To obtain more detailed anatomic information about the protection of the labyrinth with the transpetrosal approach.Methods　Twenty sides of 10 adult cadaver heads fixed in formalin were used, the anatomy of the bony labyrinth and the relationship of the correlative structures were observed and measured, and meanwhile the actual surgical procedure was mimicked under the surgical microscope.Results　The bony labyrinth was a compact and lustrous bone, which encircled the membranous labyrinth. The bony semicircular canal was drilled until it was so thin that the membranous canal was visible as blue color, called blue line. But this manipulation was more difficult in the bad pneumatized mastoid. There was significant variability in the morphometry of the adult temporal bone. The average overlying thickness of the bone overlying the posterior semicircular canal (PSC) was 3.1 mm±1.3 mm, and that of the bone overlying the superior semicircular canal (SSC) was 1.5 mm ±0.7 mm. The distance from the PSC to the sigmoid sinus was 8.6 mm±2.2 mm.Conclusion　In order to keep the labyrinth intact, two criteria are important and should be taken into account . The first one is the deviation of the labyrinth location, which is so great that the labyrinth can not be precisely located during operation. The second one is the pneumatization of the mastoid; the more dense the boneis, the more difficult it is to expose the blue line. Recognizing the bony semicircular and never penetrating the blue line are important principles.