Transcanal endoscopic ear surgery for conductive hearing loss caused by a malleus bar: A case report and literature review

Abstract

The malleus bar indicates the bony bar that connects the bony tympanic ring and the malleus, first reported in 1988 by Nomura et al. A 9-year-old girl was referred to our hospital for adenoid hyperplasia and suspected sleep apnea syndrome. Hearing loss was suspected in the patient based on the findings of the right ear and history obtained at the first outpatient visit. Thus, pure tone audiometry and tympanometry were performed. The pure tone hearing average on the affected side was 51.7 dBHL and on the left side was 15.0 dBHL, with a maximum air-bone gap of 40 dB on the affected side. The tympanogram of the right side was type C, whereas the left side was type A. Computed tomography revealed a high-density structure extending backward from the malleus. Therefore, an exploratory tympanotomy and transcanal endoscopic ear surgery was planned for the possible detection of the malleus bar. Malleus bar and ossicular chain dysfunction were detected during the surgery; therefore, we performed the tympanoplasty IIIi-M. The postoperative pure tone hearing average of the affected side improved to 18.3 dBHL. According to previous reports, a possibility for better hearing improvement was observed in patients who underwent ossiculoplasty along with the removal of the malleus bar. Therefore, transcanal endoscopic ear surgery can be considered useful for the treatment of malleus bar.