Correlation of middle ear risk indices and hearing outcome in tympanoplasty: a prospective study of chronic otitis media patients

Abstract Background Chronic otitis media is a permanent abnormality of the pars tensa or pars flaccida which is predisposed by a middle ear pathology (Flood, J Laryngol Otol 132:1042–4, 2018). The most important clinical feature is conductive hearing loss. The treatment of choice is reconstructive surgery called tympanoplasty which is performed once the ear is dry to prevent graft failure. There are various risk factors which influence graft uptake and hearing outcome following tympanoplasty. The most important risk factors are ear discharge, presence of cholesteatoma, erosion of ossicles, history of previous surgery or smoking. Middle Ear Risk Index is one such prognostic tool which helps in predicting the outcome following tympanoplasty in patients of Chronic Otitis Media. Objective To correlate middle ear risk indices and hearing outcome in patients undergoing tympanoplasty with/without mastoidectomy. Methodology This study was conducted in the Department of Otorhinolaryngology at KS Hegde Charitable Hospital. Subjects diagnosed with chronic otitis media who underwent tympanoplasty with/without mastoidectomy were included in this study after written informed consent. Details were recorded in the performa. All cases were subjected to Pure Tone Audiometry and findings were recorded. Based on the details, Middle Ear Risk Index was calculated. Three months post-operatively, patients were assessed on parameters such as graft uptake by otoscopy, evaluation of hearing, tinnitus, and any other complaints, and repeat PTA was done. These findings were then evaluated and compared with preoperative findings. All data was tabulated in an Excel sheet and analyzed. Result The study was conducted on 82 subjects diagnosed with Chronic Otitis Media who underwent tympanoplasty with/without mastoidectomy. Subjects were divided into 3 categories according to the Middle Ear Risk Index. Forty-three subjects were in mild category, 29 subjects were in moderate category and 10 subjects were in severe category. Subjects undergoing tympanoplasty with/without mastoidectomy showed statistically significant graft uptake as well as hearing improvement in both left and right ear for all three categories of the Middle Ear Risk Index. Conclusion According to our study, MERI may not accurately predict the outcome in patients under undergoing tympanoplasty with/without mastoidectomy. The individual risk factors of MERI can also be used as prognostic indicators. It was observed that external factors such as sterility and post-operative care as well as the patient’s own hygiene practices greatly influenced the outcome of tympanoplasty.