Relationship between Eustachian tube function and location of the perforation in chronic otitis media

Abstract

Background: Eustachian tube function (ETF) has been the center of focus as a prognostic factor because of its presumed primary role in the pathogenesis of otitis media and clearance of the middle ear cavity. There is a general agreement that adequate ETF is necessary for middle ear surgery. In this study, the incidence of ET dysfunction and its patency has been evaluated in inactive mucosal variety of chronic otitis media, in relation to the types of central perforation. Materials and Methods: A cross-sectional study was done with 54 patients presenting with inactive mucosal type of chronic otitis media. All the recruited patients were first examined clinically and under microscope and then their audiological (impedance audiometry) and radiological assessment of mastoid was done. Alongside otoendoscopy, nasal endoscopy, dye test were done. In all these cases, other routine investigations were also performed. Results: Impedance audiometry offers an easy means of assessing ETF. The automatic Toynbee test can be a practical, objective and suitable method to assess ventilatory function of ET. The saccharin test is a simple, cost-effective and is valuable diagnostic tool to assess the mucociliary function of the ET. Mucociliary and ventilatory function may vary in the same patient. Saccharin test and methylene blue tests are comparable. Patients having poor saccharin test, methylene blue test, and ventilatory test are more prone to develop central perforation posterior to the handle of the malleus. The most frequent abnormal finding at nasal endoscopy was edema about the tubal orifice. Conclusion: A clinically useful test for ETF is still lacking. Impedance audiometry offers an easy means of assessing ETF. Ventilatory function of ET which is the single most important contributory factor in the pathogenesis of chronic otitis media should be evaluated with the objective method before tympanoplasty.