Residual Hearing Outcomes After Cochlear Implant Surgery Using Ultra-flexible 28-mm Electrodes.

OBJECTIVE

To evaluate the preservation of low frequency residual hearing after cochlear implant surgery using an electrode for atraumatic implantation and complete cochlear stimulation.

STUDY DESIGN

Retrospective clinical record study.

SETTING

Tertiary referral center.

PATIENTS

Fifty-six patients with functional deafness who had undergone cochlear implant surgery and received a Flex electrode (MED-EL GmbH, Innsbruck, Austria) between 2011 and 2014.

INTERVENTION

Audiometric testing was performed before surgery and at the time of initial fitting.

MAIN OUTCOME MEASURE

Change in low frequency residual hearing measured by pure tone audiometry.

RESULTS

Preoperative hearing was relatively poor. After surgery low frequency residual hearing was partially preserved in most cases, however there was a significant hearing loss at all frequencies compared with the preoperative state. In only 23% of all cases complete hearing preservation was observed.

CONCLUSION

Despite the use of a flexible electrode, complete preservation of low frequency residual hearing can only be achieved in a minority of patients. The use of a full insertion electrode of 28 mm in patients with poor preoperative thresholds does not allow for usable additional hearing at present.