The Effect of Middle Ear Surgery on Sensory Neural Hearing Level Patients Suffering from Chronic Otitis Media

Introduction: Since middle ear surgery may lead to sensory neural hearing impairments, this study was carried out to evaluate the sensory neural hearing level after middle ear surgeries in Kashani’s educational and Therapeutic center, affiliated by Isfahan University of Medical sciences during 2002-4.

Materials and Methods: This study was designed as a clinical trial. 90 cases with Chronic Otitis Mecdia (COM), who were admitted in hospital for Tympanoplasty and Mastoidectomy were  selected for the study. A pre and post, bone conduction hearing test was performed on the abnormal ear in Frequencies 250 to 4000 HZ. By means of AMPLID319, Auditory tests were performed in one Audiometry Center by one expert audiologist. Other variables like age, gender,  kind of surgery, diagnosis of the lesion of the middle ear and duration of drilling were investigated and evaluated too. Then descriptive statistics (frequency, correlation ,…) and inferential statistics (Paired t-test, Chi-square) were utilized to evaluate hearing level before and after surgery.

Results: Mean age of subjects were 25.17. 53.3% of cases were females, and the rest were males. 33.3% underwent left Tympano-mastoid surgery, and 25.6%1right Tympano-mastoid. Chelesteatoma was the most common diagnosed disease in middle ear(37.8%). Drilling duration was 31.19± 16.51 minute. There was not a statistically significant difference between the mean of hearing levels in pre and post operated cases except for the point of 250 HZ. Also, no significant difference was found between duration of drilling and diagnosis of the lesion of middle ear, and hearing loss.

  Conclusion: As the results of this study showed no difference in hearing level was found between pre and post operated cases, therefor it seems that by observing and considering the primary principles of ear surgery, no more sensory neural hearing loss will appear, and there is no need to be much more worried or sensitive in this regard.