Evaluation of Inner Ear Damage by Using Otoacoustic Emissions in Patients Who Underwent Mastoidectomy and Tympanoplasty Operations in the Early Period.

Objective We aim to demonstrate inner ear damage caused by drilling in the early period. Healthy contralateral ears of patients who underwent mastoidectomy using drill or tympanoplasty without using drill were compared. Methods A total of 38 patients (mastoidectomy: 22, tympanoplasty: 16) who were diagnosed as chronic otitis media and were scheduled for surgery were included. Distortion product (dp) otoacoustic emissions measurements were performed on healthy contralateral ears of patients on pre- and post-operative 1. hour, 1. day, 2. day, 3. day, and 4. day. Results In mastoidectomy group, dp otoacoustic emission values on post-operative 1. hour, 1. day, 2. day, 3. day, and 4. day at a frequency of 4000 Hz were significantly lower than in tympanoplasty group (p<0.05). In mastoidectomy group, dp values on post-operative 1. hour, 1. day, 2. day, 3. day, and 4. day at 4000 Hz significantly decreased in comparison with pre-operative period (p<0.05). In comparison with pre-operative period, decrease in dp values on post-operative 1. hour, 1. day, and 2. day at 4000 Hz in mastoidectomy group is significantly higher than those in tympanoplasty group (p<0.05). In tympanoplasty group, dp values on post-operative 1. hour at 4000 Hz significantly decreased in comparison with pre-operative period (p<0.05). Conclusion Drilling used in mastoidectomy operation damage healthy contralateral ears by causing acoustic trauma. This damage can be determined by otoacoustic emissions in the early period. According to our study, hearing loss is temporary and more distinct at higher frequencies.