Correlation of Preoperative HRCT Temporal Bone Findings with Intraoperative Findings in Patients Undergoing Tympanomastoidectomy

Abstract

Background: High-resolution computed tomography (HRCT) of the temporal bone is routinely used for the preoperative evaluation of chronic suppurative otitis media (CSOM) with cholesteatoma. However, its accuracy in predicting intraoperative findings remains variable. This study aimed to evaluate the correlation between preoperative HRCT temporal bone findings and intraoperative findings in patients undergoing tympanomastoidectomy, and to assess the diagnostic usefulness of HRCT in preoperative surgical planning. Materials and Methods: This prospective longitudinal observational study was conducted in the Department of Otorhinolaryngology at a tertiary care teaching hospital from June 2020 to November 2022. A total of 129 patients aged >6 years with CSOM planned for tympanomastoidectomy were included. All patients underwent clinical evaluation, otoendoscopy, otomicroscopy, pure tone audiometry and HRCT temporal bone followed by surgery. HRCT findings regarding disease extent, ossicular chain, facial nerve canal, tegmen plate, sigmoid sinus plate, lateral semicircular canal and other anatomical structures were compared with intraoperative findings. Diagnostic accuracy was assessed using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Statistical analysis was performed using Chi-square/Fisher's exact test, with p<0.05 considered statistically significant. Results: The majority of patients were aged 21–30 years (24.8%), with a male predominance (55.8%). HRCT showed significant agreement with intraoperative findings for the extent of cholesteatoma (p<0.001). It demonstrated excellent diagnostic accuracy for tegmen plate, sigmoid sinus plate and high-riding jugular bulb, and good accuracy for malleus erosion, lateral semicircular canal erosion and fallopian canal dehiscence. Lower diagnostic accuracy was observed for incus and stapes erosion. Conclusion: Preoperative HRCT temporal bone demonstrated good correlation with intraoperative findings and is a valuable adjunct for preoperative assessment and surgical planning in tympanomastoidectomy. However, it has limitations in differentiating cholesteatoma from mucosal disease and in accurately predicting certain ossicular erosions.

Keywords: Chronic suppurative otitis media; Cholesteatoma; High-resolution computed tomography; Temporal bone; Tympanomastoidectomy; Diagnostic accuracy.