Round window accessibility in transcanal approach

Abstract

AimOur aim of this study is to evaluate the transcanal approach to visualize the round window whose visualization is a very important and challenging topic as it is used as a portal for electrode insertion during cochlear implantation.MethodsThis study was carried out over fifty patients suffered from conductive or mixed hearing loss with intact tympanic membrane suggested to be otosclerotic patients irrespective to their age or sex. The exploratory tympanotomy procedures were performed. The tympanomeatal flap is considered to be completely elevated when the posterior edge of long process of malleus, the long process of incus, the stapes and the stapedial tendon were visible and the flap is reflected anteriorly without tension. At this step, visualization of round window is assessed microscopically and endoscopically by using an oto-endoscope of 2.7mm diameter and 30 angle.ResultsBy using the microscope, we found that 48 cases were fully visible (Type 1), 1 case was partially visible (Type 2) and 1 case was not visible (Type 3). By using the endoscope, we found that the round window details are fully visible in all the fifty cases.ConclusionWe experienced that better exposure of round window could be achieved with less effort via transcanal approach. Using the endoscope gives panoramic view with clear details. So, transcanal approach can be used instead of classic posterior tympanotomy to visualize the round window.