Persistent conductive or mixed hearing loss after the placement of tympanostomy tubes.

Objective: Described is a case series of clinical findings in children with persistent conductive or mixed hearing loss following tympanostomy tube placement for serous otitis media.

Study Design: Retrospective chart review.

Setting: Tertiary pediatric hospital.

Subjects/methods: Medical records of thirty-nine children who were referred for either conductive or mixed hearing loss post-tympanostomy tube placement were reviewed for clinical histories, physical examinations, audiological evaluations, diagnostic studies, consultations, and surgical findings. Approval was obtained from the Boston Children's Hospital Institutional Review Board.

Results: Causes of hearing loss included ossicular abnormalities, cochlear abnormalities, 'third window' effects, cholesteatomas, genetic syndromes, and unknown causes. In four patients with isolated mild low-frequency conductive hearing loss, the cause was the presence of functional tubes. All patients diagnosed with a genetic syndrome had bilateral hearing loss. Patients with mixed hearing loss were diagnosed with cochlear abnormalities, 'third window' effects, or genetic syndromes. Computed tomography led to diagnosis in sixteen of twenty-five patients. Vestibular-evoked myogenic potential testing suggested a diagnosis in three of four patients.

Conclusion: In children with persistent hearing loss following tympanostomy tube placement, identifying the laterality and type of hearing loss appears to be of importance in diagnosis. Patients with bilateral hearing loss should be considered for genetic testing, given the possibility of a syndrome. Patients identified with a mixed hearing loss should be evaluated for inner ear anomalies. Patients with mild, low-frequency hearing losses should be monitored audiologically and investigated further only if the hearing loss progresses and/or there is no resolution following tube extrusion.