Dexamethasone eluting electrodes for cochlear implantation: Effect on residual hearing

Abstract

Electrode array with prolonged release of DXM improved short-term preservation of residual hearing after implantation for the frequencies 500, 1000, 4000, and 16 000 Hz in gerbils. The long-term results at 1 year confirmed these data for higher frequencies, but must be verified for the lower frequencies of 500 and 1000 Hz.

Effects of a dexamethasone-releasing implant on cochleae: A functional, morphological and pharmacokinetic study

“…Stathopoulos et al (2014) demonstrated no significant difference in ABR thresholds compared to a no-eluting electrode in guinea pigs. The present study used both ABR with DPOAE measurements and found that significant hearing recovery occurred in the DEXA group at frequencies of 8e24 kHz (ABR thresholds) and 4e16 kHz (DPOAE measurements), which is consistent with Douchement et al (2014). The electrode in the present study was implanted via cochleostomy approximately 1 mm above the edge of the round window niche, and the insertion depth in the scala tympani was 3 mm.…”

“…The significant recovery of postoperative auditory function in the DEXA group suggests that dexamethasone released from an electrode for at least 12 weeks protects inner ear function after cochlear implantation by inhibiting inflammation and delaying immune responses in the cochlea (Astolfi et al, 2014). Douchement et al (2014) implanted gerbil cochleae with a dexamethasone-incorporated electrode and found that hearing was better preserved at frequency of 16 kHz 1 year postoperatively. Stathopoulos et al (2014) demonstrated no significant difference in ABR thresholds compared to a no-eluting electrode in guinea pigs.…”

“…The longest study to date is a 1-year postoperative study reported by Douchement et al (2014), wherein gerbil cochleae were implanted with dexamethasone-incorporated rods. Some studies in guinea pigs had a duration of approximately 3 months (Braun et al, 2011;Lee et al, 2013;Stathopoulos et al, 2014), but most studies were limited to 4e5 weeks postoperatively (Eshraghi et al, 2007;Huang et al, 2007).…”

“…Using pharmaceutical methods, dexamethasone can be incorporated into electrodes. The drug-releasing profiles and functional effects of these electrodes are an ongoing subject of research (Farahmand Ghavi et al, 2010;Jolly et al, 2010;Farhadi et al, 2013;Nguyen et al, 2015;Douchement et al, 2014).…”

Cochlear Implants: An Excursus into the Technologies and Clinical Applications

“…This provides the possibility for stimulating the region responsible for high-frequency hearing in cochlea without stimulating regions responsible for low frequency hearing. Primary studies have revealed that hybrid implant application is associated with better hearing preservation and increased speech perception [35,36,57,58].…”