[Ionomer cement in cochlear implant surgery--applications and long-term outcome]

Over the last ten years about 850 cochlear implant operations were performed at the ENT department of Hannover Medizinische Hochschule. In most cases, intracochlear nucleus implants were used. For about two years the intracochlear Clarion device has also been used in 150 adults and children. For several years we have used ionomeric cement (lonocap, supplied by lonos, Seefeld/Germany) to fix the electrode array in the region of the posterior wall and the facial recess. Previously, the implant package was fixed by ionomeric cement. To evaluate the outcome of cement application, we conducted a prospective study of our implant patients during the period from 1991 to 1993. During regular reexamination over a period of two years postoperatively in 244 patients (122 male and 122 female patients, average age 17.6 years), we did not observe any complication related to the cement. Nearly all revision cases (n = 8) showed a stable contact between electrode array, bone, and cement. With increasing experience, we reduced the cement application and fixed the package with vicryl sutures in a precisely drilled bony bed. Contact of the cement with neural and cerebral structures should be avoided. In our experience ionomeric cement is a helpful tool in cochlear implant surgery with long-term stability and no rejection reactions.