Tip Fold-over with the Slim Modiolar electrode (CI 532), a retrospective case series

Introduction:

When implanting a cochlear implant from Cochlear, several types of electrodes are available. The choice depends on the audiological results of the patient and the anatomy of his cochlea. This case series illustrates a special feature of the CI electrode (CI 532) after insertion in comparison to the other types of electrodes from the same manufacturer.

Material methods:

In 300 patients, conventional CI surgery (posterior tympanotomy) performed an insertion of 100 nucleus contours (CI512), 100 nucleus SRA (CI 522), and 100 nucleus MRA (CI 532) by experienced CI surgeons. The operations took place within one year, were gender-specific and included an age group of 1 to 79 years. In addition to the technical examination of the implant (impedance test, stapedius reflex measurement), DVT imaging of the petrous bone was performed to check the position of the CI electrode.

Results:

In the DVT posture control performed in 6 patients (2% of cases) a tip fold-over of the electrodes was detected. Taking into account the types of electrodes, bending could only be detected with the MRA (CI 532) electrode. The tip fold over rate for the MRA electrode is thus 6%.

Conclusion:

The radiologically proven tip foldover in the Slim Modiolar electrode (CI 532) has crucial clinical relevance. A corrective insertion is required which can lead to prolonged surgery times and trauma to the cochlea. The intraoperatively performed DVT imaging is thus obligatory in order to avoid a new operation for the position correction. Reasons for the MRA electrode to be twisted might be special anatomical features of the cochlea.

Publication History

Publication Date:
18 April 2018 (online)