Functional hearing and low frequency hearing preservation after cochlear implant surgery is achievable with FLEX electrode arrays: Real world evidence from the MEHS Registry

This study uses data from the MED-EL Hearing Solutions (MEHS) multicenter registry to examine the impact of a series of flexible lateral wall electrode arrays on postoperative low frequency hearing preservation (LFHP) of cochlear implant (CI) users. Participants were members of the MEHS registry who had received a MED-EL CI with a FLEX electrode array. LFHP was evaluated using 2 formulae: the Vienna Consensus (VC), which assesses hearing preservation at 250‒1000 Hz; and the Minimum Reporting Standards for Adult Cochlear American Academy of Otolaryngology-Head and Neck Surgery (AAO), which assesses hearing preservation at 125‒500 Hz. LFHP was assessed via air conduction preoperatively and between 6 and 36 months postoperatively. LFHP was achievable with all the FLEX arrays evaluated, regardless of length. With the VC, 60% of ears (n = 95) had complete or partial LFHP at 6‒12 months postoperatively and 68.4% (n = 19) had complete or partial LFHP at 24‒36 months postoperatively. With the AAO, 43.4% of ears (n = 83) had LFHP at 6‒12 months postoperatively and 84.2% (n = 19) had functional low frequency residual hearing at 24‒36 months postoperatively. In conclusion, implantation with FLEX electrode arrays can preserve functional low-frequency residual hearing up to three years after implantation. The MEHS multicenter registry appears to be a valuable tool for collecting large amounts of real-world data from CI users despite challenges in harvesting usable data.