Impact of Partial Mastoid Obliteration on Caloric Vestibular Function in Canal Wall Down Mastoidectomy

Objective: To evaluate the influence of our technique of partial mastoid obliteration with autologous bone pate covered by cartilage plates on vestibular stimulation. Methods: Twenty-six patients who were treated for recurrent chronic otitis media by revision canal wall down tympanomastoidectomy and subsequent partial obliteration were invited for follow-up; 18 patients agreed to a complete follow-up including vestibular testing. Patients received questionnaires for evaluating preoperative and postoperative symptoms associated with vertigo. Examination comprised otomicroscopy, pure-tone audiometry, and caloric testing. Results: Mean follow-up was 6 years. Before surgery, 54% of the patients reported vertigo on caloric stimuli such as wind, water, or suction cleaning of the tympanomastoid cavity. In all patients, these symptoms were suspended after partial mastoid obliteration. The postoperative obliterated cavity volume aver-aged 3.1 ml. All cavities after surgery appeared completely epithelialized and dry. The postoperative caloric vestibular tests revealed an average nystagmus count of 46 beats per minute compared with 72 beats before surgery. Thus, the partial mastoid cavity obliteration led to a mean nystagmus reduction of 36% in our study group. Conclusion: Our technique of partially obliterating tympanomastoid cavities with autologous bone pate being covered by cartilage plates results in small cavities with complete epithelialization of all surfaces. Furthermore, obliteration of mastoid cavities confers protection to the labyrinthine organ, thereby reducing postoperative vertigo on caloric stimulation