J Korean Med Sci.  2022 Jan;37(2):e19. 10.3346/jkms.2022.37.e19.

Foreign Body Complications in Ears due to Mishandled Hearing Aid Fitting and Proposed Clinical Guidelines to Address the Complications

• Cho EH
• Cho EH
• Shim L
• Shim L
• Choi HG
• Choi HG
• Hong SK
• Hong SK
• Kim HJ
• Kim HJ
• Lee HJ
• Lee HJ

• KMID: 2524291
• DOI: http://doi.org/10.3346/jkms.2022.37.e19

Abstract

Background
South Korea has one of the world’s fastest aging populations and is witnessing increased age-related hearing impairment cases as well as an increase in the number of hearing aid users. The aim of this study was to analyze complications caused by hearing aid mold materials. In addition, we hope to raise awareness of the harm and danger that inexperienced hearing aid providers can cause to patients.
Methods
We retrospectively reviewed the medical records of 11 patients who were diagnosed with hearing aid mold material as a foreign body in the ear at a tertiary center between 2016 and 2020. The following data were analyzed: symptoms, endoscopic findings, audiometry, temporal bone CT images, treatment methods, and complications after removal. The currently available literature was also reviewed to develop clinical guidelines, to identify the systematic weaknesses in the South Korean hearing aid market, and to identify policies that warrant better quality control.
Results
Among the 11 cases, 9 were restricted to the external auditory canal, all of which were successfully removed under endoscopy with minor complications. Two cases with middle ear involvement resulted in infection and thus required surgical removal with mastoidectomy. The average age of these patients was 76.4, and all patients received their molding procedure at private hearing aid shops without an otolaryngologist’s examination.
Conclusion
Thorough patient history-taking and otologic examination must be performed to identify patients at higher risk of complications. Such patients should be referred to an otolaryngologist. If a patient exhibits alarming symptoms, early referral is critical since prompt surgery can minimize complications. A CT scan is highly recommended to determine an optimal approach for foreign body removal. Systematic and regulatory changes in hearing aid dispensers, such as requiring apprenticeship, raising the required level of education, and legally mandating referrals, can help reduce these complications.

Keyword

Foreign Bodies; Hearing Aids; Hearing Loss; Mastoidectomy

Figure

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  Fig. 1 Otological findings of the Case 1. (A) Green silicone material filling the middle ear seen through the perforated tympanic membrane. (B) Preoperative audiogram. (C) Temporal bone CT scan (axial view) showing high-density material filling the entire middle ear cavity and the Eustachian tube. (D) Gross photo of the removed foreign body material after canal wall-up mastoidectomy with tympanization.

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  Fig. 2 Otological findings of the Case 2. (A) The patient’s otoendoscopic exam on the first day of visit, showing moderate perforation with greenish material in the middle ear. (B) Preoperative audiogram. (C) Coronal & axial view of temporal bone CT showing high-density material in the middle ear cavity. (D) Otoendoscopic exam showing severe granulation tissue formation with otorrhea. (E) Gross photo of the removed foreign body from the middle ear. (F) Six months postoperative audiometry result.

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  Fig. 3 Gross view of earmold foreign body restricted to the external auditory canal.

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  Fig. 4 A proposed clinical guideline algorithm to address foreign body complications in ears due to hearing aid impression materials.HA = hearing aid, EAC = external auditory canal, CT = computed tomography, COM = chronic otitis media, TM = tympanic membrane.

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