Significance of internal auditory canal diverticula in ears with otosclerosis

Abstract

Background: Diverticula in the internal auditory canal (IAC) have been reported in ears with otosclerosis.

Objective: We evaluated hearing levels and vascular activity in ears with otosclerosis with and without IAC diverticula and clarify the significance of IAC diverticula.

Materials and methods: Sixty-one ears from 54 patients who underwent stapes surgery for otosclerosis [fenestral (48 ears) and retrofenestral (13 ears) groups] were included in the present study. Preoperative hearing levels on pure tone audiometry (PTA) and intraoperative measurements of blood flow were compared between the groups.

Results: A total of 24 of 61 ears (39.3%) showed IAC diverticula, significantly higher than the frequency in ears without otosclerosis (3.7%). No significant differences in air- and bone-conduction thresholds on PTA were evident between ears with and without IAC diverticula in each group. Ears without IAC diverticula tended to show higher blood flow in the area anterior to the oval window than ears with IAC diverticula, but the difference was not significant.

Conclusions: The incidence of the IAC diverticula in otosclerosis was significantly higher than in cases without otosclerosis. The existence of IAC diverticula was not evidently related to the severity of the disease from the perspective of hearing level and vascular activity.

Chinese abstract

背景：据报道, 在耳硬化症患者耳中有内耳道憩室（IAC）。

目的：评价伴和不伴IAC憩室的患耳硬化症耳的听力水平和血管活性, 澄清IAC憩室的作用。

材料与方法：本研究包括54例耳硬化症[小孔（48耳）和复小孔（13耳）组]镫骨手术患者的61只耳朵。比较两组患者术前纯音听力测试（PTA）和术中血流测量结果。

结果：61耳中有24耳（39.3%）表现出具有IAC憩室, 明显高于无耳硬化症的耳（6.1%）。各组有IAC憩室和无IAC憩室的耳在PTA的气导和骨导阈值上无明显差异。无IAC憩室的耳在卵圆窗前区较有IAC憩室的耳血流量更大, 但差异不显著。

结论：IAC憩室在耳硬化症患者中的发生率明显高于无耳硬化症患者。从听力水平和血管活动角度看, IAC憩室的存在与疾病的严重程度无明显关系。

Keywords:

• Internal auditory canal diverticulum
• otosclerosis
• hearing level
• blood flow
• laser-Doppler flowmetry

Disclosure statement

No potential conflict of interest was reported by the authors.