The evaluation of surgical findings with preoperative computed tomography findings in chronic otitis media cases

Chronic otitis media (COM) is defined as the ear drum perforation with or without ear discharge for three months despite the medical treatment. The purposes of surgery in COM are to eradicate the infection in the middle ear, to preserve and even, if possible, to improve hearing and to prevent recurrencies after obtaining a safe and dry ear with closing the perforation.The aim of this study is to compare the operative and temporal bone computed tomography (CT) findings of the 70 patients that were planned to undergo open or closed tympanomastoidectomy operations due to COM between February 2006-February 2008 in the otorhinolaryngology department of the School of Medicine, Afyon Kocatepe University.Age and genders of all patients were recorded and they all underwent a thoroughly otorhinolaryngologic examination and audiologic evaluation. The patients that were planned to operate underwent high resolution CT scanning of the temporal bones with a spiral MDCT (6 raws) (Philips Brilliance, Holland) in the radiology department of the School of Medicine, Afyon Kocatepe University. All the scanning were performed with axial images, if required, coronal reformatted images were obtained after 3-dimension volume rendering of the axial images. It was planned to compare the presence of soft tissue in the middle ear and mastoid cavities, mastoid pneumatization pattern, the presence of soft tissue in sinus tympani, the erosion of ossicular chain, the dehiscence of facial canal, the dehiscence of labyrinthine canal, dural exposure and erosion of sigmoid sinus wall in the questionnaire which was designed before the study.The temporal bone CT and operative findings of the patients were recorded according to the mentioned criteria above. Sensitivity, spesificity, positive and negative predictive values of each criteria was calculated with using the temporal bone CT and operative findings.Thirty-five (50%) of the 70 cases were male and 35 (50%) of them were female. The mean age of the cases was 30.6±14.4, ranged from 4 to 64 years. While cholesteatoma was accompanying with 35 (50%) of the 70 cases, it was not accompanying with 35 (50%) of them.The sensitivity of temporal bone CT in the determination of erosion of sigmoid sinus wall, mastoid pneumatization pattern, the presence of soft tissue in the middle ear and mastoid cavities was found to be 100%, 97%, 93% and 90% respectively. The sensitivity of temporal bone CT in the determination of erosion of ossicular chain and the presence of soft tissue in sinus tympani was found to be 79% and 67%, respectively. The sensitivity of temporal bone CT in the determination of the dehiscence of labyrinthine canal, the dehiscence of facial canal and dural exposure was found to be 50%, 46% and 36%, respectively. Since the erosion of ossicular chain, the presence of soft tissue in sinus tympani, the dehiscence of labyrinthine canal and facial canal, dural exposure and erosion of sigmoid sinus wall in temporal bone CT is accompanied with COM with cholesteatoma peroperatively with high rates, COM with cholesteatoma should be considered when the presence of soft tissue in the middle ear and mastoid cavities in temporal bone CT is accompanied with the findings mentioned above.In conclusion, we suggest that spiral computed tomography is so beneficial in the preoperative evaluation of chronic otitis media; with the advantages of the parallel improvement in accordance with the development of computer technology, and high resolution and 3-dimensional imaging in the aspects of preoperative patient counselling, medicolegal status and the decreasing of probable peroperative complications to the least.