[The non-damaging method for the insertion of a standard electrode for cochlear ossification].

The objective of the present study was to develop the non-damaging method for the insertion of a standard electrode for cochlear ossification with a view to improving the results of hearing and speech rehabilitation of the patients presenting with grade IV sensorineural impairment of hearing. Twenty preparations of the cadaveric temporal bone were used to investigate topographic and anatomical relationships in the main structures of the middle and internal ears, viz. the second cochlear coil, vestibulum and its windows, processus cochleaformis, spiral lamina, and modiolus. The optimal method for the insertion of a standard electrode into the spiral canal of the cochlea after the removal of the ossified structures is proposed. The optimal site for constructing the second colostomy is determined that allows the spiral plate and modiolus to be maximally preserved. The proposed method was employed to treat 11 patients with grade IV sensorineural impairment of hearing and more than 5 mm ossification of the basal cochlear coil. With this method, it proved possible to insert the maximum number of electrodes into the cochlear spiral canal and thereby to obtain excellent results of hearing and speech rehabilitation in the patients with the ossified cochlea.