Preoperative predictors of incudal necrosis in chronic suppurative otitis media

Abstract

Objective: To determine the predictive value of preoperative clinical, audiological, and radiological factors in diagnosing incudal necrosis in patients with tubotympanic chronic suppurative otitis media (CSOM).

Study design: Case series with planned data collection.

Setting: Tertiary care referral center.

Subjects and methods: Patients older than five years of age diagnosed with tubotympanic CSOM who underwent tympanomastoid surgery were recruited. Findings on otoscopy, x-ray mastoid, pure-tone audiometry, and intraoperative otomicroscopy were recorded.

Results: Incus necrosis occurred in 24 (16%) of a total of 150 patients. On bivariate analysis, findings of active ear discharge (P = 0.01), anterosuperior location of perforation (P = 0.03), exposure of incudostapedial joint (P = 0.05), edematous middle ear mucous membrane (P = 0.05), middle ear granulations (P = 0.004), foreshortening of the handle of malleus (P = 0.04), moderate to moderately severe hearing loss (41-70 dB HL) (P = 0.000), and air-bone gap > 40 dB (P = 0.001) were found to be associated with incus necrosis. Intraoperative findings of aditus block (P = 0.001) and mastoid granulations (P = 0.005) were also found to be significantly associated with incus necrosis. Mastoid pneumatization and perforation size and site were not associated with incus necrosis. On multivariate analysis, only middle ear granulations (P = 0.04; odds ratio [OR] 3.161; 95% confidence interval [95% CI] 1.087-9.196) and a moderate to moderately severe hearing loss (41-70 dB HL) (P = 0.03; OR 1.720; CI 1.064-2.782) were found to be significant risk factors.

Conclusion: Incus necrosis is best predicted by the presence of middle ear granulations and moderate to moderately severe hearing loss (41-70 dB HL). Knowledge of this information preoperatively can influence surgical decision making and preparedness regarding ossiculoplasty and patient consent.