Otoendoscopy and Audiometry Findings as Predictors of Ossicular Dysfunction in Mucosal Chronic Suppurative Otitis Media: A Cohort Study

Introduction: Chronic Suppurative Otitis Media (CSOM) is chronic inflammation of epithelial lining of the middle ear cleft. Ossicular discontinuity and or erosion is known in CSOM with cholesteatoma but at times it can be associated with tubotympanic CSOM which surprises the operating surgeon. This study to determine the relationship between preoperative and otoendoscopic findings in cases of CSOM was undertaken to facilitate surgeon in planning about dealing the disease before rather than having surprise at exploration. Aim: To study predictors of ossicular dysfunction in cases of mucosal CSOM. Materials and Methods: This prospective cohort study of 64 cases was undertaken at Krishna Institute of Medical Sciences, Karad, Maharashtra, India, from November 2018 to April 2020. All cases were subjected to detailed clinical, otoscopic, and microscopic examination to assess the size of perforation, granulation tissue, tympanosclerosis, exposure of incudostapedeal joint, and condition of middle ear mucosa. A pure tone audiogram was also done. All cases underwent tympanoplasty with or without cortical mastoidectomy and the intraoperative findings of ossicular erosion were noted. All cases with granulation or polypoidal mucosa on otoscopic examination as well as mastoid exploration were subjected to histopathological examination for confirmation of disease pathology. Using Chi-square test with Yates continuity correction the variables data was processed and results were analysed. Results: Out of the 64 cases, 15(23.4%) had ossicular erosion. Bivariate analysis showed a positive association for middle age group between 31-40 years (p-value<0.001), long-duration of disease (p-value<0.004), polypoidal middle ear mucosa (p-value<0.002), granulations in the middle ear (p-value<0.001), and also when the incudostapedeal joint was exposed (p-value<0.005) through the subtotal perforation (p-value<0.022). On audiological evaluation moderate to moderately severe hearing loss (41-70 dB HL) (p-value<0.0015), and air-bone gap >40 dB (p-value<0.001) were associated with incus erosion. Intraoperative findings like aditus block (p-value<0.001) and mastoid granulations (p-value<0.001) were also found to be significant risk factors associated with incus erosion. Conclusion: Preoperatively identifying the predictors of ossicular dysfunction like granulation tissue in the middle ear and raised pure tone audiometric average threshold can help the surgeon to better understand pathology of the disease and helpful too while counselling the patients to meet the realistic expected outcome of surgery.