A surgical approach for a cochlear implant: an anatomical study.

This study has demonstrated the anatomical relations of the cochlea to structures in the medial wall of the tympanum, and has shown that surgical access can be obtained to the terminal auditory nerve fibres supplying the basal, middle and apical turns of the cochlea. It is suggested that a cochlear implantation should be carried out in two stages. The first stage should be modified radical mastoidectomy, and in the second stage electrode arrays should be implanted into the three cochlear turns through openings made in the proximal and distal portions of the basal turn, and the distal portion of the middle turn.