Clinical Study of Labyrinthine Fistula in Cholesteatomatous Chronic Otitis Media: A Tertiary Care Hospital-Based Retrospective Study in a South Indian Population

Abstract

Introduction: Among the extracranial complications of cholesteatoma, the most common is labyrinthine fistula (LF). The causes are still poorly understood for cholesteatoma-induced labyrinthine fistula. Some of the possible factors described in the literature are the patient's age, duration of the disease, growth pattern of cholesteatoma, and disease aggressiveness. These affect the site of development of labyrinthine fistula. Cholesteatoma and its complications pose a great burden on the economic and health sector of developing nations.

Aim and objective: The objective is to estimate the incidence of labyrinthine fistula in cholesteatomatous chronic otitis media (COM) and analyze the clinical presentation and post-surgical improvement in hearing and vertigo in the study cohort.

Materials and method: The study was conducted in the Department of Otorhinolaryngology. It involved retrospective data collection of case records between 2018 and 2022. All patients diagnosed with chronic otitis media (COM) with cholesteatoma were reviewed retrospectively in a tertiary healthcare center. Of the 324 cases reviewed, 21 had an LF.

Results: The incidence rate of LF in our study was 6.48%. Sixteen (76.1%) patients were male, and five (23.9%) were female. The youngest patient was a 10-year-old male, and the oldest was a 51-year-old female. The mean ± standard deviation (SD) age was 34.09 ± 10.05 years. The left ear (76.1%) was affected more than the right ear. All cases were from rural areas, and 16 (76.1%) of them were farmers. Ear discharge (85%) was the most common symptom, followed by hearing loss (76%) and then vertigo (47%). A very peculiar risk factor of self-cleansing the ear was noticed in all patients. Out of the 21 patients who underwent surgery, it was observed that the lateral semicircular canal (LSCC) was the commonest site of the fistula. According to the Dornhoffer and Milewski classification, type II LF was the commonest type. In one patient with a type III LF, a foreign body (a piece of a twig) was found intraoperatively near the LSCC fistula site. Two patients had multiple fistulae. Six patients had associated mastocutaneous fistula, and one had facial nerve paralysis. All patients, except one, were free of vertigo following surgery. Postoperatively, the bone conduction thresholds were similar to the pre-surgical values in 12 of 16 (74%) patients.

Conclusion: The incidence of LF is still higher in developing countries, predominantly in rural populations, where the habit of self-cleansing the ear is a common practice. The common symptoms of COM with LF are ear discharge, hearing impairment, and vertigo. All the cases had a habit of frequent self-cleansing of the external ear as an important risk factor. Therefore, implementing awareness programs on maintaining aural hygiene in rural health centers may reduce the incidence of cholesteatomatous LF, thereby preserving hearing and vestibular functions and improving the quality of life. However, the above statement needs further validation with large multicenter studies.