经颅中窝入路内耳道的定位研究

A study on identification of the internal auditory canal in middle fossa surgery

目的:探讨经颅中窝入路确认内耳道的定位方法。方法:12例成人头颅湿标本,在手术显微镜下解剖观察,辨认颧弓根后点、棘孔后唇、锤骨头和内耳道间的位置关系。结果:锤骨头的位置相对恒定,其与颧弓根后点和棘孔后唇距离分别为(19.44±1.48)mm和(17.74±1.32)mm。以颧弓根后点和棘孔为原点,分别在颅中窝做内径18mm弧线,两弧交叉处外侧钻5mm骨孔,即可辨认锤骨头。颧弓根后点至锤骨头连线,向内延长则落在内耳门内外侧界之间,在此磨除岩嵴即可打开内耳道内侧份,内耳门距锤骨头约(19.71±1.97)mm。结论:经颅中窝手术时,锤骨头可作为确认内耳道的安全可靠的解剖标志。

Objective: To describe a safe technique for identification of the internal auditory canal in middle fossa approach. Methods: Twelve adult cadaver heads were dissected to define the anatomical relationship among the root of the zygoma, the posterior lip of the foramen spinosum, the head of the malleus and the internal auditory canal. Resluts: The distance from the head of the malleus to the root of the zygoma and the posterior lip of the foramen spinosum was (19.44±1.48) mm and (17.74±1.32) mm respectively. The point of intersection of an arc drawn 18mm from the root of the zygoma and the posterior lip of the foramen spinosum localized on the head of the malleus, which can be exposed by drilling a 5mm hole on the point. The line extending from the root of the zygoma through the head of the malleus just reached the acoustic poms. The distance between the head of the malleus and the acoustic porus was (19.71±1.97) mm. Conclusions: The head of malleus may serve as a reliable and safe landmark in the middle fossa surgery when other landmarks are unrecognizable .