Poznań's program of cochlear and brainstem implantation: a general review

The cochlear implantation program in Poznań started in January 1994. Within 8 years, 151 patients were implanted (149 cochlear and 2 auditory brain-stem implants). The implanted group comprised 111 children and 40 adults. We have extended the lower age limit for cochlear implant candidates, and the youngest implanted patient was 18-months-old at the time of surgery. We have also implanted six multi-handicapped subjects. All patients were implanted with different nucleus devices (22, 24 M, 24 K, 24 Contour, 24 Double Array and 24 ABI). Insertion of the Nucleus 24 Contour electrode carrier requires a little larger cochleostomy in comparison with conventional straight array. After insertion, the intraoperative measurements are taken (impedance telemetry, electrically evoked stapedius reflex and NRT). The day after surgery, each patient undergoes an X-ray examination (the cochleogram or cochlear view). The calculated length of the electrode array insertion was 12.75-24.0 mm (mean: 22.05 mm) and the degree of electrode rotation was 180-540 degrees (mean: 292.82 degrees). After speech processor switch-on, we performed NRT measurements. Our results indicated that the NRT threshold was in 51.4% of the dynamic range within the group of examined patients. The adults' progress of rehabilitation was checked during individual sessions. The rehabilitation of children included two rehabilitation schedules: continuous ones and weekly rehabilitation camps. The progress of the recovery process of implanted children enabled them to change their school profile from hearing impaired to mainstream. Voice rehabilitation is often monitored by acoustic analysis using the Multi Dimensional Voice Program (MDVP).