Biologic Fixation of the Electrode Cable of Cochlea Implants

Objectives: To verify the necessity for special surgical techniques or clips for fixation of the electrode cable of a cochlea implant against dislocation, and to test the stability of postoperative biologic cicatrization as the sole and solid anchoring of the cable. Material: Temporal bone experiments with a simulated connective tissue sheath around conventional (Med El Combi 40+) and prototype (profiled surface) electrode cables. Results and Conclusions: The electrode cable is anchored securely in a sheath of scar tissue, since unphysiologic loads are needed for pulling it out of its anchorage. The drag during one extraction trial with a profiled cable even resulted in the rupture of the cable. These results confirm our confidence in this biologic fixation of the electrode cable inside its postoperative cicatric tissue sheath. More than 80 cochlea implantations with the electrode simply imbedded in a drop of fibrin glue in the posterior tympanotomy never demonstrated a shift of the electrodes in the last 8 years. Therefore, special fixation of the electrode cable with clips or surgical techniques is not necessary.