Cochlear Implantation in the Cochlea with an Anteriorly-Located Sigmoid Sinus

The standard surgical technique for cochlear implantation consists of mastoidectomy, posterior tympanotomy and cochleostomy (facial recess approach). We performed cochlear implantation in a patient with an anteriorly-located sigmoid sinus, which made posterior tympanotomy impossible. Since the short process of the incus was partly defective in this case, the electrodes of the cochlear implant (Nucleus 24) were introduced through the space from the epitympanum to mesotympanum after opening the epitympanum from the area superior to Macewen's triangle. The cochleostomy was performed by a transmeatal approach. All 22 electrodes and 10 dummies were inserted into the cochlea without any resistance.