Change of Tympanogram after Chronic Otitis Media Surgery / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Pre-operative eustachian tube function (ETF) is an important factor for the postoperative success after tympanoplasty, though much debates have been reported. In this study, we investigated the tympanogram changes after tympanoplasty, indirectly checking up ETF, to find out the relationship between tympanogram changes and associated factors of tympanoplasty. SUBJECTS AND METHOD: Included in this study were 238 cases of tympanoplasty (canal wall up mastoidectomy with tympanoplasty type I or tympanoplasty type I only) performed by one surgeon for chronic otitis media from January, 2012 to June, 2017. In all cases, tympanometric tests were undertaken at one month, three month, six month, and one year post-operatively, and pure tone audiometry tests were taken at 1 year, post operatively. RESULTS: The average hearing level and air-bone gap were 41.8±19.7 dB, and 17.1±9.3 dB, pre-operatively, and 29.9±21.1 dB, and 6.9±8.5 dB, 1 year post-operatively, respectively. Most of the cases showed improvement in hearing. The results of tympanometry showed that hearing improvement was greater for the A type than for the B or C type (p<0.001). The smaller the size of the tympanic membrane was, the higher, the type A tympanogram appeared to be (p=0.008). CONCLUSION: The estimation of pre-operative ETF using post-operative tympanogram changes can give insight to the degree and process of recovery of the normal middle ear after tympanoplasty.