Comparison of preoperative computed tomography findings with peroperative surgical findings of ossicular chain status inchronic otitis media

Chronic otitis media (COM) is a chronic infection and inflammation of the middle ear and mastoid, most of the time clinically manifested by discharge and hearing loss. Chronic otitis media is usually a result of recurrent acute otitis media episodes or chronic otitis media with effusion. Changes in the ossicular chain is one of the distinct pathologic findings due to COM. The risk of ossicular erosion increase especially in presence of cholesteatoma. Many factors like duration of pathology, concomitance of cholesteatoma may play a role in destruction of the ossicular chain. Computed tomography (CT) has been widely used in recent years for the evaluation of the middle ear and temporal bone pathology. Direct graphies and conventional tomography have been replaced by CT after 1980s. Today the chance to obtain more and detailed information about pathology of the middle ear has become available via high-resolution computed tomography technology that provides decreased slice thickness and increased resolution. The aim of our study was to determine the accuracy of CT scan by comparing the preoperative CT findings with the peroperative findings in patients with chronic otitis media. In this study, preoperative CT findings of 208 patients, who underwent to open or closed technique tympanomastoidectomy due to 43 chronic otitis media in Afyon Kocatepe University Faculty of Medicine, Ear Nose Throat Department between September 2009 and May 2015, were compared with their surgical findings. In our study, we observed that there was distruction of middle ear ossicles in patients with chronic otitis media. We found ossicular erosion was higher in patients with cholesteatoma when compared to the patients without cholesteatoma. In our study, when we compared preoperative computed tomography findings with peroperative findings of patients; CT could determine cholesteatoma in mastoid and middle ear space with 74% sensitivity, 64% specificity, 85% positive predictive value (PPV) and 24% negative predictive value (NPV), respectively. Considering ossicular defect, CT could demonstrate the destruction of malleus with 83% sensitivity, 71% specificity, 67% PPV and 66% NPV, destruction of incus with 74% sensitivity, 87% specificity, 92% PPV and 40% NPV, destruction of stapes with 69% sensitivity, 52% specificity, 59% PPV and NPV 51%, respectively. We found out icus was the most frequently damaged ossicle in chronic otitis media, followed by malleus and stapes. We observed that preoperative temporal bone CT could assess the ossicular chain status rather accurately, especially for incus and malleus. In determining ossicular chain destruction in patients with cholesteatoma, we reached the conclusion that findings of ossicular chain destruction in CT could be judged in favor of cholesteatoma with values of 81% sensitivity, 75% specificity, 93% PPD and 48% NPV. As a result, we found out CT had a higher rate of sensitivity in showing the damage of malleus and incus rather than stapes.On the other hand we observed that CT was not enough to demonstrate minimal ossicular erosions. 44 We reached the conclusion that it would be beneficial to evaluate the patients with chronic otitis media by preoperative temporal bone CT for planning the operation in the most accurate way and minimizing complications that may be encountered during the surgery.