Jahrsdoerfer R A
Laryngoscope. 1981 Aug;91(8):1217-25. doi: 10.1288/00005537-198108000-00001.
The two most common anomalies of the facial nerve encountered in patients with a congenital malformation of the middle ear are displacement of the nerve and lack of a bony cover, two conditions that place the nerve at risk of being injured by the unwary surgeon. Malformations of the stapes are often found in association with facial nerve anomalies and may range from underdevelopment to complete absence. A congenital absence of the oval window is not uncommon. The position of the facial nerve in relation to the location and maturation of the ossicles will determine the method of ossicular chain repair. Creation of a new oval window by drilling may require the surgeon to purposely displace the facial nerve to ensure a more direct alignment of the prosthesis with the vestibule. Any part of the incus or malleus may be contoured by drilling to accommodate the loop end of the wire-piston prosthesis. An aberrant course of the facial nerve was found in 13/54 (24%) ears having a congenital malformation of the middle ear. All 54 ears had a patent external ear canal and an identifiable tympanic membrane. Patients with atresia or stenosis of the external ear canal were specifically excluded from this study.
中耳先天性畸形患者中最常见的两种面神经异常是神经移位和缺乏骨质覆盖，这两种情况会使神经有被粗心的外科医生损伤的风险。镫骨畸形常与面神经异常相关，其范围可从不发育到完全缺失。先天性卵圆窗缺失并不少见。面神经相对于听小骨的位置和成熟情况将决定听骨链修复的方法。通过钻孔创建新的卵圆窗可能需要外科医生有意移位面神经，以确保假体与前庭更直接对齐。砧骨或锤骨的任何部分都可以通过钻孔进行塑形，以容纳钢丝活塞假体的环端。在54例中耳先天性畸形的耳朵中，有13例（24%）发现面神经走行异常。所有54只耳朵的外耳道均通畅且鼓膜可识别。外耳道闭锁或狭窄的患者被特意排除在本研究之外。
