Vol. 6, Issue 2, Part A (2024)

Background: The Eustachian tube (ET) is a connecting tube between the tympanic cavity and the nasopharynx, which has three main functions: maintaining middle ear pressure, draining middle ear secretions through mucociliary clearance, and protecting the middle ear from nasopharynx sound and pathogen reflux. The success of tympanoplasty depends on many factors, one of which is the proper functioning of the Eustachian tube. To find out the evaluation of Eustachian tube function using impedance audiometry and comparison of surgical outcomes in terms of graft incorporation in normal and abnormal Eustachian tube function.
Methods: A prospective study included 100 patients with chronic suppurative otitis media with central perforation (CSOM) who visited the Department of Otolaryngology-Head and Neck Surgery, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from January to December 2023. The study included 100 patients diagnosed with mucosal-type chronic suppurative otitis media in the quiet or inactive phase. A detailed medical history was collected for all patients, an ENT examination was performed, and radiological examinations were performed. Eustachian tube function was assessed using impedance audiometry. Preoperative and postoperative results of Eustachian tube function were compared, and the results were analyzed.
Results: Out of 100 patients between age group of 17 to 45 years with mucosal type of CSOM, either in inactive or quiescent stage were included in study. All cases were of unilateral ear disease. 40% patients (40/100) were in the age group of 17-20 years. Male to female ratio was 1:1.5. Otorrhoea was the main complaint in all cases with 52% patients (52/100) having duration of discharge between 1-10yrs. Majority of patients were seen in quiescent stage of the disease i.e 65% (65/100) during first visit. On impedance audiometry 60% patients had normal Eustachian tube function and 40% had impaired function. Overall graft takes up rate was 91.0% and failure rate was 9.0%. Tympanoplasty was successful in 93.3% patients with normal Eustachian tube function and in 87.5% with impaired function and difference was not statistically significant (P >0.05). Hearing improvement in terms of air-bone gap closure (AB gap < 20db) was more in patients with normal Eustachian tube function (60%). 
Conclusion: Impedance audiometry is a simple and direct method to assess Eustachian tube function. Not only the anatomical patency but also the physiological function of the Eustachian tube is evaluated. The outcome of tympanoplasty is successful if the Eustachian tube is functioning normally, but Eustachian tube dysfunction is not a reason to refuse the procedure.