Preservation of Low frequency residual hearing after implantation of a perimodiolar CI532-electrode

The perimodiolar CI532-electrode (Cochlear Ltd.) enables the preservation of high levels of residual hearing due to a low diameter and flexible electrode design. This study’s aim was to assess the levels of frequency-dependant residual hearing after implantation.

A number of 57 Cochlear Implants with CI532-electrodes were inserted at our clinic from 2015-2018. In six cases a revision surgery was necessary due to misplacement of the electrode. The implant was replaced by a different implant. Accordingly, 51 implantations were retrospectively analysed (age at surgery 58±16 years). Residual hearing was tested at 3 appointments: audiograms were done preoperatively (T0), within 30 days after surgery (T1) and at a second aftercare appointment (15,5 ±10,4 months, T2).

Within the time interval T0-T1 there was no significant deterioration of residual hearing at the frequency levels 125 and 250 Hz. However, at frequency levels >250 dB a significant decline of on average 10 dB (p <0,05) was shown.

Within the time interval until the second aftercare appointment (T1-T2) residual hearing at 250Hz declined significantly by 17 dB. At the remaining frequency levels, no differences were shown.

The CI532-electrode allows the preservation of residual hearing at low frequencies. However, in this study’s observation period a significant deterioration at 250 Hz was shown. Further research is necessary to analyse residual hearing in long-term follow-up.

Poster-PDF A-1637.PDF

Publication History

Article published online:
10 June 2020