Cochlear implant and inflammation reaction: safety study of a new steroid-eluting electrode.

Cochlear implant and inflammation reaction: safety study of a new steroid-eluting electrode. Hear Res. 2016 Apr 21; Authors: Astolfi L, Simoni E, Giarbini N, Giordano P, Pannella M, Hatzopoulos S, Martini A Abstract Dexamethasone is a common anti-inflammatory agent added to cochlear implants to reduce hearing loss due to electrode insertion trauma. We evaluated the safety of eluting silicone rods containing 10% dexamethasone in a Guinea pig model. Animals were implanted with a dexamethasone eluting silicone electrode (DER) or with a non-eluting electrode (NER). The control group only underwent a cochleostomy (CS). Prior to implantation and during the two weeks following implantation, the hearing status of the animals was assessed by means of Compound Action Potentials (CAPs) with an electrode placed near the round window. Two weeks after implantation, the mean click threshold shifts were 1dB +/- 10dB in the DER group, 10dB +/- 10dB in the NER group and -4dB +/- 10dB in the control group. After two weeks the bullae of each animal were extracted to verify the presence of macrophages, the percent of tissue growth in the scala tympani and the tissue sealing around cochleostomy. Silicone electrodes samples were also explanted and examined for bacterial infection. Neither bacterial infection nor enhanced number of macrophages were observed. A limited, but not significant, tissue growth was found in the scala tympani between the experimenta...
Source: Hearing Research - Category: Audiology Authors: Tags: Hear Res Source Type: research