Hearing Preservation With Full Insertion of the FLEXsoft Electrode

Abstract

Objectives Hearing preservation (HP) in the context of cochlear implantation (CI) is indicative of an atraumatic insertion, which could potentially offer a clinical advantage to performance, whether such preservation was intended for the application of electoacoustic stimulation (EAS). Our goal was to determine the degree of HP after the implantation of a full-length electrode array (MedEl FLEXsoft). Study Design Prospective, within-subject repeated measure design. Methods Adult patients with residual low-frequency hearing who received a 31.5-mm FlexSoft electrode array were included. Implantation using soft surgery techniques occurred at a single tertiary referral center between 2008 and 2011. Preoperative and postoperative audiometric data were compared. Results In 36 consecutive patients at 1 year postimplantation, 6 (21%) maintained complete HP (an increase of low-frequency pure-tone average (PTA) ≤10 dB from the preoperative value), and 19 (65%) maintained partial HP (an increase in low-frequency PTA ≤40 dB from the preoperative values) throughout the follow-up period (average, 368 d). Higher preoperative hearing threshold levels (HTLs) at 1,000 Hz were associated with HP. Conclusion Low-frequency HP is possible in patients implanted with the full-length FlexSoft electrode. Longer follow-up is required to determine if results are maintained over time and if such preservation is in fact advantageous to clinical outcomes. Level of Evidence: 4