Department of Otorhinolaryngology, Alexandria University School of Medicine, Alexandria, Egypt.
Department of Otorhinolaryngology and Neuro-Otology, Gruppo Otologico, Piacenza, Rome, Italy.
J Int Adv Otol. 2021 Jan;17(1):23-29. doi: 10.5152/iao.2020.8927.
To assess the effect of the position of the SS on CI regarding the ability to perform posterior tympanotomy, round window visibility, and mastoid pneumatization.
This is a prospective study, including 65 adult patients with CI performed at our center during 2017. We used 3 methods to assess SS position using a computed tomography (CT) scan. Lee's line passing through the tympanic segment of the facial nerve. Park's line passing through the facial nerve and round window membrane. Our proposed method using a parallel line from the external auditory canal and passing through the facial nerve. Relation to mastoid pneumatization on CT and to intraoperative round window visibility were assessed in relation to intraoperative position of the SS.
The method by Park et al. was statistically significant (p<0.001); however, a cutoff point could not be set. Lee's method was statistically insignificant (p=0.091). Our proposed method was statistically significant with a cutoff point at ≤2.46 mm (p=0.001). SS position did not affect pneumatization nor round window visibility.
The position of SS preoperatively using a CT might suggest the inability to perform posterior tympanotomy and the need to change side or approach. However, it does not affect neither mastoid pneumatization nor visibility of the round window niche through the facial recess.
评估 SS 位置对 CI 术后行后鼓室切开术、圆窗显露和乳突气房气化能力的影响。
这是一项前瞻性研究，纳入了 2017 年在我院行 CI 的 65 例成年患者。我们使用 3 种方法，通过 CT 扫描评估 SS 位置：李线，即穿过面神经鼓室段的线；朴线，即穿过面神经和圆窗膜的线；我们提出的方法，即从外耳道引出的与面神经平行的线。根据 CT 上的乳突气房气化情况和术中圆窗的显露情况，评估 SS 位置与术中位置的关系。
朴线方法具有统计学意义（p<0.001）；然而，无法设定截断值。李线方法无统计学意义（p=0.091）。我们提出的方法具有统计学意义，截断值为≤2.46mm（p=0.001）。SS 位置不影响气房气化，也不影响经面神经隐窝显露圆窗。
术前 CT 评估 SS 位置可能提示无法行后鼓室切开术，需要改变侧别或入路。然而，它既不影响乳突气房气化，也不影响经面神经隐窝显露圆窗。
