Relationship between changes in hearing function and volumes of endolymphatic hydrops after endolymphatic sac drainage

Abstract

Background: Endolymphatic sac drainage (ELSD) may have a positive effect on endolymphatic hydrops (EH) and may help to preserve inner ear function. However, the relationship between changes in EH volumes and hearing function after ELSD has not been described.

Objectives: We aimed to reveal the factors related to changes in hearing and EH following ELSD.

Material and Methods: Twenty-one patients who received ELSD were enrolled. Pure tone audiometry and 3-T magnetic resonance imaging (MRI) 4 h after intravenous injection of gadolinium enhancement were performed just before surgery and 2 years later. To characterize the endolymphatic space (ELS), we measured the volume of the total fluid (TFS) and ELS and calculated the ratio of ELS to TFS (ELS ratio).

Results: The ELS ratio of the patients who showed hearing improvement was 18.5 ± 11.4% before surgery and 23.9 ± 14.3% after. For those with no change, it was 29.7 ± 10.8% before and 29.4 ± 9.5% after, and in patients with worsened hearing function it was 22.7 ± 7.5% before and 27.2 ± 13.4% after.

Conclusion: We found no correlation between the changes in hearing function and the volume of EH after ELSD.

Chinese abstract

背景：内淋巴囊引流（ELSD）可能对内淋巴积水（EH）有积极作用, 可能有助于保护内耳功能。然而, 在ELSD之后的EH量的变化与听力功能变化之间的关系尚未被描述。

目的：发现ELSD术后听力和内淋巴积水变化的相关因素。

材料与方法：对21例接受ELSD治疗的患者进行研究。术前和术后两年, 静脉注射钆增强剂4小时后进行纯音测听和3-T磁共振成像（MRI）。为了表征内淋巴间隙（ELS）, 我们测量了总液体（TFS）和ELS的体积, 并计算了ELS与TFS的比值（ELS比值）。

结果：听力改善者的术前ELS比值为18.5 ±11.4%, 术后ELS比值为23.9± 14.3%；对听力无变化者, 术前ELS比值为29.7 ±10.8%, 术后为29.4± 9.5%；听力减弱者, 术前为22.7± 7.5%, 术后为27.2 ±13.4%。

结论：ELSD术后听力变化与内淋巴积水体积变化无相关性。

Keywords:

• Meniere’s disease
• endolymphatic hydrops
• sac surgery
• hearing function
• MRI

Acknowledgments

We would like to thank Professors Shinji Naganawa and Toshiaki Taoka (Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan) and Mr. Tsuyoshi Sakamoto (PixSpace Ltd., Kokura, Fukuoka, Japan) for technical support. We also thank Editage (www.editage.jp) for English language editing.

Disclosure statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Additional information

Funding

This work was supported by JSPS KAKENHI Grant Number 18K09354 Grant-in-Aid for Scientific Research (C), AMED under Grant Number 18dk0310092h000, and Health and Labour Sciences Research Grant for Research on Rare and Intractable Diseases (H29-Nanchito (Nan)-Ippan-031) from the Ministry of Health, Labour and Welfare of Japan. We also thank Editage (www.editage.jp) for English language editing. Japan Agency for Medical Research and Development; Japan Society for the Promotion of Science;.