الفهرس | Only 14 pages are availabe for public view |
Abstract Summary and conclusion The present study’s main objective was to compare between the two most commonly used techniques for insertion of the cochlear implant electrode into the scala tympani of the cochlea to optimize cochlear implantation results and to allow patients with severe to profound SNHL to get the most benefits of their implant devices. For that purpose, the present study recruited large sample of patients (n = 200) and divided them equally on two groups. The first group received the cochlear implant device through the round window approach and named the RW group while the second group received the cochlear implant device through the standard cochleostomy technique and named the C group. The C group acted as a control group for comparison and patients of both groups were evaluated for their cochlear implantation outcomes via standardized, validated and reliable tests for each outcome, for speech perception the patients were tested using the CNC word recognition test and the BKB open-set sentence recognition. For language acquisition the patients were tested by the Preschool Language Scale-fourth edition (PLS-4) and the Peabody Picture Vocabulary Test, Fourth edition (PPVT-4). For speech production the patients were tested by using the Diagnostic Evaluation of Articulation and Phonology (DEAP). All the participants in this study had to take all the previous tests twice after they received the cochlear implant for their results to be included in this study, the first time was between 24 to 30 months post-implantation while the second time they were tested between 31 to 36 months post-implantation. The results of this study indicated that patients who received cochlear implantation by using the round window approach demonstrated significantly higher scores in all tests regarding speech perception, language acquisition and speech production when compared with patients who received the device through the standard cochleostomy insertion technique. These results were consistent with the results of several studies that indicated that the round window insertion, being less traumatic method for insertion of the electrode, is associated with better electrical stimulation for the cochlear neural elements, minimal production of fibrous tissue around the electrode, minimal production of neo-ossification inside the cochlea and associated with better perimodiolar placement of the electrode which brings the electrode closer to the modiolus and the osseous spiral lamina of the cochlea. The present study concluded and recommends the following points: Round window insertion is associated with better cochlear implantation outcomes regarding speech perception, language acquisition and speech production than the standard cochleostomy insertion. Insertion of the electrode through the round window of the cochlea is safe and effective method for cochlear implantation. In patients with favorable temporal bone anatomy, the round window should be clearly visible and easily accessible. However, in some cases of cochlear implantation the round window is obscured and in that case the surgeon must look for the round window by all available means including widening of the facial recess opening, using angled endoscopes or even sacrificing the chorda tympani to visualize the round window. However, some round windows will remain obscured for the surgeon’s view and in that case cochleostomy will be the last choice to insert the electrode. The new modified St Thomas’ Hospital (STH) classification suggested by the current study is strongly recommended to be taken into consideration for CI surgeons to do the round window insertion with all the possible means to get the best benefits of cochlear implantation. The study results recommend more future prospective studies and systematic reviews to compare between the round window and the cochleostomy insertion in the future to set the round window insertion as the standard method for electrode insertion in cochlear implantation. |