Evaluation of the implant electrode inside the cochlea and damage to cochlear structures associated with implantation using cone beam computed tomography techniques (CBCT)

Objectives: The aim was to evaluate the position of the cochlear implant electrode inside the cochlea and damage to cochlear structures associated with the implantation itself using cone beam computed tomography technique (CBCT). Material and methods: Nine human cadaver temporal bones were used, five were implanted with round window approach and in other four anterior cochleostomy was used for insertion. After implantation the temporal boneswere scanned with CBCT scanner and the images were then analyzed. The degree of insertion damage was evaluated in two-tier scale, where the first degree included damage to basilar membrane, and the second degree covered damage associated with pushing up into the scala vestibuli. Results: The first degree of cochlear damage was noted in three temporal bones implanted with the round window approach and in two with cochleostomy, and the second degree of damage was noted in two and one temporal bones respectively. The analysis did not show any correlations between depth of insertion and degree and extend of damage in both analyzed groups, also no significant differences were found between the two groups. Conclusions: The good quality of the images presents CBCT as a good method for the evaluation of the cochlear implant electrode position in the inner ear structures. CBCT holds the promise for intraoperative imagining during cochlear implantation.