Speech Performance Following Intraoperative Correction of Cochlear Implant Electrode Array Tip Fold-Overs

Cochlear implant (CI) electrode array tip fold-overs occur at an increased rate with perimodiolar electrode arrays, necessitating removal and re-insertion. The degree to which an intra-operative correction of tip fold-over affects CI performance and hearing preservation has not been previously reported.

Retrospective chart review of CI recipients receiving a slim perimodiolar electrode array from 2016 to 2023.

Tertiary referral center.

Low-frequency pure tone average (LFPTA) was defined as the average of thresholds at 125, 250, and 500 Hz. We defined hearing preservation candidacy as LFPTA < 60 dB HL preoperatively, and successful hearing preservation was defined as LFPTA < 80 dB HL at activation. Consonant-nucleus-consonant (CNC) word recognition and AzBio scores in quiet and in +10 dB signal-to-noise ratio (SNR) were collected preoperatively, and at 3- and 6-months postoperatively.

From 663 implants, 35 (5.3%) experienced tip fold-over that was identified and corrected intra-operatively. There was no significant difference in 3-month CNC scores between those with fold-overs (44.9%, SD 20.9%) and those without (46.2%, SD 21.0%; P = .98). Similarly, there was no difference in AzBio in quiet (53.1%, SD 21.7% vs 60.8%, SD 28.0%; P = .26) or in AzBio +10 dB SNR (19.1%, SD 23.7% vs 31.5%, SD 27.2%; P = .60). Of 19 hearing preservation candidates that experienced tip fold-over, 6 (31.6%) had preserved hearing at activation compared to 31 of 59 candidates (52.5%; P = .11) without fold-over.

While tip fold-over remains a clinical concern, speech performance does not appear to be negatively affected if the fold-over is identified and corrected.