Exploratory Tympanotomy For Conductive Hearing Loss with Intact Tympanic Membrane: What To Expect Intraoperatively?

Background: Exploratorytympanotomy is done to identify the cause ofconductivehearingloss in a patient withintacttympanic membrane. Objective: Toenlist and analyze the middle ear pathologies in patients with conductive hearing loss with intact tympanic membrane. Methods: 50 patients in age group between 20 years and 50 years, with hard of hearing, consulting department of ENT at a tertiary care hospital, were evaluated. Clinical examination, pure tone audiometry and tympanometry were done for all patients. Patients with conductive hearing loss with intact tympanic membrane were taken up for exploratory tympanotomy. Results: Most common middle ear pathology in the study was otosclerosis. Differential diagnoses for clinical and audiological findings suggestive of otosclerosis were anatomical abnormalities of ossicles& restricted ossicular mobility. Other middle ear causes for conductive hearing loss were ossicular necrosis and adhesive otitis media. Tympanic membrane abnormalities in the form of thin tympanic membrane, retracted tympanic membrane and myringosclerosis were found to be associated with conductive hearing loss in the absence of any middle ear cause. Patients with history suggestive of healed chronic middle ear infection were found to have more probability of middle ear sequalae in the form of middle ear adhesions, tympanosclerotic patches over the ossicular joints resulting in restricted ossicular mobility and ossicular necrosis. Conclusion:The study provide saninsight in to different causes of conductive hearing loss behind anintacttympanic membrane and illustrates fewinstances where abnormal middle earanatomy inter feres with surgical correction of conductive hearingloss.