中耳显微解剖标志与面神经定位

Microscopic anatomical landmarks of the middle ear for the localization of the facial nerve

目的观察中耳手术中面神经相关的显微解剖结构,并探讨其临床应用。方法 30具(60侧颞骨)中国人成年湿性头颅标本经乳突入路对颞骨进行显微解剖,重点观察面神经并根据其周围的固定解剖标志对其进行定位。结果面神经乳突段前缘和后缘至假想定位线的距离分别为(-0.11±0.36)mm和(-0.14±0.38)mm,鼓室段面神经下缘与假想定位线的距离为(0.31±0.12)mm,砧骨短脚末端至外半规管下缘的距离为(1.73±0.24)mm,外半规管至面神经锥段上缘的距离为(2.65±0.25)mm,砧骨短脚最末端至面神经锥段上缘的距离为(2.20±0.41)mm,镫骨头上缘至面神经水平段下缘的距离为(2.24±0.23)mm等。结论外半规管、砧骨短突、鼓环、二腹肌嵴、前庭窗、匙突、卵圆窗、锥隆起和鼓索神经等是中耳显微手术的重要解剖标志,并与面神经关系极其密切和恒定。

Objective To observe the microdissection structure of the facial nerve in middle ear surgery and to clarify its clinical significance.Methods Microdissection was performed on 30 Chinese adult wet skulls via the transmastoid approach.The location of the facial nerve was identified by its stationary anatomic landmarks nearby. Resules The distances of both ends of the mastoid segment of the facial nerve to the imaginary line of the position were （-0.11±0.36）mm and （-0.14±0.38）mm, respectively. The lower edge of the tympanic segment of the facial nerve to the imaginary line of position was （0.31±0.12）mm. The trailing edge of short limb of incus to the lower edge of the lateral semicircular canal was （1.73±0.24）mm. The lateral semicircular canal and the trailing edge of short limb of incus to the upper edge of cavity segment of facial nerve were （2.65±0.25）mm and （2.20±0.41）mm, respectively. The upper edge of stirrup bone to the horizontal segment of facial nerve was （2.24±0.23 ）mm. Conclusion Important anatomic landmarks for middle ear surgery include the lateral semicircular canal, short limb of incus, incustympanic ring, digastric ridge, vestibular, cochleariform process, oval window, pyramidal eminence, and chorda tympani nerve. These structures are closely related with the facial nerve. Thus, these anatomical features may paly an important role in localizing the facial nerve, avoiding iatrogenic injury, and improving operative quality.