Hearing results of surgery for tympanosclerosis

Abstract

Between January 1990 and December 2003, 117 patients were surgically treated for tympanosclerosis at a tertiary referral center. The objective of our study was to review the hearing results in this cohort. The patients were divided into three groups: predominant involvement of tympanic membrane (33 cases), predominant fixation of malleus or/and incus (72 cases), and stapedial fixation (12 cases). Preoperative and postoperative air-bone gap (ABG), and pure tone average (PTA) were compared after short-term and long-term follow-up, and statistical significance was determined. After surgery, air-bone gap was improved by 11.7 dB after short-term, and by 10.9 dB after long-term observation period. The improvement of ABG was not significantly different between the groups. Pure tone average (PTA) was improved by 15.2 dB in short-term period, with decrease of results in the long-term follow-up to 10.3 dB. Successful hearing result as judged by ABG was obtained in 66.7% with affected tympanic membrane, in 65.3% with malleus or/and incus fixation, and in 50.0% with stapedial fixation. Statistical analysis confirmed significant improvement of hearing for all groups. Highly significant difference was noted for low frequency ABG (0.5, 1, and 2 kHz). Hearing improvement on ABG was preserved after long-term observation. No significant sensorineural hearing loss was seen in this series. Surgery for tympanosclerosis results in significant improvement of ABG and PTA. Most of the improvement is obtained in lower frequencies. Long-term results are comparable to short-term results, with slight hearing deterioration in stapedial fixation.