New Technique for Fixation of Cochlear Implant Electrodes Preventing Extrusion and Rotation of the Array

BACKGROUND: Cochlear implants (CIs) have evolved to address diverse hearing impairments, expanding indications to include patients with residual hearing. Preserving residual hearing enables electro-acoustic stimulation, potentially improving CI outcomes. While “soft surgery” techniques are widely adopted to minimize immediate cochlear trauma, post-insertion electrode movements during the coiling of the electrode lead in the mastoid remain understudied. This study proposes novel surgical techniques of electrode fixation to minimize post-insertion movement. METHODS: A pilot study, in collaboration with Cochlear® (Mechelen, Belgium), examined the feasibility of stabilization grooves in the mastoid and removable stabilization material in the posterior tympanotomy during coiling. Objectives included minimizing axial rotation of the precurved perimodiolar 532/632 electrodes, improving electrode lead fixation, preventing intraoperative changes in the insertion depth, and assessing pediatric applicability. RESULTS: Combination of both proposed techniques allowed for stable electrode placement. The use of a removable sterile sponge in the posterior tympanotomy prevented axial rotation of the electrode beyond 90° and alterations in insertion depth, particularly during placement of the electrode in the attical groove and the subsequent coiling of the excess lead in the mastoid. The study also confirmed the feasibility of these techniques in pediatric models. CONCLUSION: The proposed techniques seem to be effective in securing electrode placement in the cochlea after insertion. These techniques involve only minor adaptations to the standard procedure, without the need for costly material or a substantially longer operating time. The authors therefore believe they have the potential for systematic implementation. Further research is required to validate these techniques and explore their impact on overall CI performance.