NUCLEUS DOUBLE ELECTRODE ARRAY - A NEW APPROACH FOR OSSIFIED COCHLEAE

Introduction: The ossified cochlea is still a special surgical issue t hat requires a special surgical procedure. The current cochlear implan ts only have one electrode lead, which can be placed only partially in the drilled out basal turn. The small number of used active electrode s leads to worse performance as compared with patients with full inser tion. Methods: To overcome this limitation, a special electrode was de veloped consisting of two arrays. One array with 11 active electrode r ings is placed in the drilled out basal turn, the second array with 10 active electrodes in the opened second turn. The number of inserted e lectrodes can be significantly increased. The surgery is similar to th at in nonossified cochleae. After the posterior tympanotomy, the bridg e is removed and the incus is located. A cochleostomy is performed at the basal turn and the new-built tissue removed. A second cochleostomy is placed below the cochleariform process. In most cases, the second turn is not obliterated and the second electrode array can be fully in serted. Results: The surgical procedure was in all nine cases uneventf ul. Intraoperative stapedius reflex could be recorded with elevated th resholds. The wide variety of stimulation modes and sites allows an in dividual fitting to maximize the performance. All patients show a gap in the pitch scale between the apical and the basal array. The pitch v ariation is much smaller in the apical array. All patients have some b enefit from the additional apical array and an improved performance. C onclusion: The nucleus double electrode array is an advanced treatment option for patients with ossified cochleae. The receiver/stimulator i s a regular nucleus cochlear implant.