Reliability of high-resolution CT scan in diagnosis of ossicular tympanosclerosis.

Objectives: To evaluate the reliability of high-resolution CT scans (HRCT scans) in the diagnosis of tympanosclerosis and to determine its benefit to predict the post-surgical hearing outcome based on comparing radiological and surgical findings.

Methods: A retrospective study at a tertiary institute included 940 ears that underwent tyampanoplasty for chronic suppurative otitis media (CSOM) between January 2013 and March 2017. Preoperative temporal bone HRCT scans were analyzed to check for the prediction of tympanosclerosis and ossicular fixation. Intraoperatively, ossicular chain integrity was checked. Preoperative and postoperative audiometric evaluations using air-bone gap (ABG) were compared. A postoperative pure-tone ABG of 20 dB or less was considered as a successful hearing result. Results are compared with historical control groups, the study has been reviewed and approved by the IRB at the medical research center in Hamad Medical Corporation; however, it is a retrospective study so no informed consent was obtained from the patients.

Results: The study included 940 ears that underwent tympanoplasties due to CSOM, where 238 out of 940 (25.3%) of ears showed tympanosclerosis during tympanoplasty, intraoperatively, tympanosclerosis was localized to the eardrum in 174 of the 238 involved ears (73.1%), A 64 out of 238 (26.9%) of the ears with tympanosclerosis showed ossicular fixation, divided as 45 ears with Incudo-malleal fixation, 14 ears with stapes fixation, and 5 ears with triple ossicular fixation. HRCT scan of the temporal bone was suggestive of ossicular chain fixation in 79 cases distributed as 55 incudo-malleal fixations, 19 stapes fixation, and 5 complete ossicular fixations, with a sensitivity of 96.8%, and specificity of 98%. The audiological results were analyzed, with a patient follow-up after 6 months.

Conclusions: Our study showed that CT scans when combined with the clinical findings can be an informative guide to otolaryngologists for preoperative evaluation and counseling of tympanosclerosis surgeries.