Pre-operative predictors of ossicular necrosis in chronic otitis media-mucosal type

Abstract

Background: Chronic suppurative otitis media can cause a wide range of pathologies in the middle ear that include irreversible mucosal changes, granulation tissue formation, cholesteatoma, tympanosclerosis, and destruction of ossicles. Knowledge regarding ossicular discontinuity before surgery enables the surgeon to be prepared for ossiculoplasty. Objective was to study the pre-operative clinical, audiological and microscopic findings in chronic otitis media mucosal type and correlate preoperative findings with intra-operative ossicular necrosis. 

Methods: Study design was observational, descriptive and cross sectional study. All patients were subjected to detailed clinical, otoscopic and microscopic examination to assess the size and site of perforation, presence or absence of ear discharge, granulation tissue, tympanosclerosis in the middle ear, exposure of incudostapedeal joint and condition of middle ear mucosa. Pure tone audiogram was also done. All patients underwent tympanoplasty±cortical mastoidectomy and the intraoperative findings of ossicular necrosis were noted.  

Results: Of the 105 patients, 18(17.1%) had ossicular necrosis. Bivariate analysis showed positive correlation for long standing disease (p=0.004), presence of discharging ear (p=0.014), polypoidal middle ear mucosa (p=0.000) granulations in middle ear (p=0.000) and also when incudostapedeal joint was exposed (p=0.005). Mean Air bone gap was higher with 35 dB in ossicular necrosis and 22.7 dB in intact ossicular chain was also statistically significant (p=0.0001).

Conclusions: Ossicular necrosis was best indicated by the presence of polypoidal mucosa, granulation in the middle ear and higher air-bone gap on audiometry. However longer duration of disease, persistent active stage of disease and exposure of incudostapedeal joint were also found to be significant.