Cochlear reimplantations: technical and surgical failures.

Conclusion: Cochlear implant surgeons should have a good knowledge of how to diagnose device failures and how to deal with medical complications related to cochlear implantation. Electrode array misplacement may be due to unidentified inner ear malformation. Use of peroperative telemetry and radiographic examination should help to avoid such complications.
Objectives: To review our experience of cochlear implant revision surgery and to compare our series to the literature. To report two cases of electrode array misplacement into the vestibular system and to discuss how to prevent this complication.
Subjects and Methods: This was a retrospective review of cochlear implant revision surgery in a tertiary reference center.
Results: Of 487 cochlear implantations, 3.8% of adults and 4.5% of children underwent a revision surgery. The mean time to device failure was 7.6 years in children and 1.5 year in adults. Causes of revision were seven hard failures, four soft failures, and nine medical reasons. Among the medical reasons, four patients had skin flap infection associated with an extended endaural approach. Audiologic performances were stable or improved following reimplantation in 90% of cases. We had two cases of electrode array misplaced into the vestibular system.