Hearing Preservation With Full Insertion of the FLEXsoft Electrode

Abstract

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). Prospective, within-subject repeated measure design. 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. 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. 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. 4.