Assessment of the preoperative classification for computed tomography predictability of round window niche visibility through posterior tympanotomy during cochlear implant surgery

Abstract

Background Transmastoid facial recess is the classical approach for cochlear implant. Many methods have been reported in the literature to detect round window niche (RWN) visibility through posterior tympanotomy during that approach. Many had unclear methodology or complex software needed for their application.Objective The aim of the present study was to assess the preoperative predictability of multislice computed tomography for RWN visibility posterior tympanotomy.Patients and methods Computed tomography scans of 32 pediatric cochlear implant patients with otherwise normal temporal bone anatomy were studied for RWN visibility through posterior tympanotomy, using two methods. The first was a modification of a method by Kashio and colleagues and another by Mandour and colleagues. The visibility of the RWN was assessed intraoperatively after performing the posterior tympanotomy. Statistical analysis was then performed.Results The method of Kashio and colleagues was of statistical significance (P=0.002), whereas the method of Mandour and colleagues was statistically insignificant (P=0.465).Conclusion Kashio and colleagues is an easy and accurate method to preoperatively predict the visibility of the RWN through posterior tympanometry.