Evaluation of HRCT parameters that could predict surgical complications in patients with otosclerosis - A pilot study

Purpose/Objectives In order to avoid intraoperative surgical complications during stapes surgery for otosclerosis, middle ear anatomy assessment in preoperative HRCT plays an important role. As stated in the literature, preoperative HRCT should provide information about the width of the oval window of the niche (Wown), depth (Down) and facial-promontory angle (FPA), preferably cochlear aqueduct dimensions and possible inner ear malformations. The aim of this study was to determine if these morphological parameters and conditions differ between the group of patients with otosclerosis and the control group, thus whether they are determined by this specific condition. Methods and materials This prospective study included 37 patients with radiologically detectable foci of otosclerosis (47 ears) and 41 patients with a diagnosis of noise-induced hearing loss. Their HRCT scans of the temporal bones were analysed for the previously mentioned morphological parameters and presence of inner ear malformations. Result FPA, Wown and Down showed overall lower values in otosclerotic compared to the control group, but with the significant decrease only in the value of FPA (p=0.034). Cochlear aqueduct dimensions showed a slight increase in length in otosclerotic patients but without significant difference. Regarding inner ear malformations, we detected only one patient with enlarged vestibular aqueduct in the control group. Conclusion We could suggest that morphological differences in the middle ear morphology occur as a diffuse effect on bone turnover within a temporal bone in patients with otosclerosis; however, due to the sample size limitation, we cannot exclude morphological variations.