Purpose: Tympanotomy and sealing of labyrinthine membranes has become in some centers used to treat severe to profound sudden sensorineural hearing loss refractory to conservative treatment. The aim of this retrospective study was to determine which preoperative factors influence the likelihood of postoperative recovery according to different audiological assessment criteria.
Methods: The mean final hearing threshold, the hearing improvement, the probability of a complete recovery according to two different classifications, and probability of a significant recovery of 136 adult subjects were studied by univariate and multivariate analyses.
Results: The subject's mean postoperative 4-pure-tone-average was 63.9 ± 35.9 dB, the mean improvement was 42.8 ± 32.6 dB. Depending on the classification system used, 18.4-28.0% of subjects experienced a complete recovery. 77.2% of subjects had a significant hearing improvement. History of a pressure change (odds ratio (OR):4.6) was the only positive prognostic factor for hearing improvement. It also enhanced probability of experiencing a complete hearing recovery (OR: 2.8-6.3). Preoperative total deafness (OR: 1.5-1.9) and vertigo (OR: 3.3-4.6) were negative prognostic factors for the mean final hearing threshold and the probability of a complete hearing recovery. Patients with a preceding pressure change event achieved a complete recovery in 45.5-50.0%, those without such an event recovered completely only in 13.2-23.7%.
Conclusion: Evaluating prognostic factors and the rate of complete hearing recovery are influenced by the underlying assessment parameters. In addition to the mean postoperative hearing threshold and hearing gain, the probability of regaining a serviceable hearing is clinically important for the individual and should be added to the assessment criteria in future studies.
Keywords: Hearing recovery; Labyrinthine window; Prognostic factors; Sealing; Sudden sensorineural hearing loss; Tympanotomy.