Inner Ear Effects of Canal Wall Down Mastoidectomy

Objective. To evaluate the inner ear effects of canal wall down (CWD) mastoidectomy without ossiculoplasty in the treatment of chronic otitis media (COM) with regard to sensorineural hearing loss (SNHL) and reported tinnitus and dizziness-related disability. Setting. Tertiary care academic medical center. Subjects and Methods. Prospective study of 86 patients treated by CWD mastoidectomy without ossiculoplasty for COM with or without cholesteatoma. Standard patient workup included preoperative audiogram and completion of 2 surveys: Dizziness Handicap Inventory (DHI) and Tinnitus Handicap Inventory (THI). Patients underwent repeat audiogram, DHI, and THI surveys at 4 to 6 months postoperatively. Preoperative and postoperative data were analyzed. Results. No significant SNHL occurred after CWD mastoidectomy. Thirteen patients (13/34 [38%]) had DHI improvement greater than 18 points, indicating a significant improvement in dizziness-related disability. Three patients developed new-onset postoperative dizziness complaints. Twenty patients (20/43 [46.5%]) had THI improvement greater than 7 points, indicating a significant improvement in tinnitus-related disability. Five patients developed new-onset postoperative tinnitus complaints. The odds ratio for improving DHI and THI scores after surgery was 6.6 (1.8 to 25.0) and 4.2 (95% confidence interval, 1.45% to 12.2%), respectively. Conclusion. In this study, CWD mastoidectomy without ossiculoplasty in the treatment of COM did not cause significant SNHL. In addition, using the DHI and THI measures, patient-perceived disability from dizziness and tinnitus, respectively, was shown to decrease after mastoid surgery.