Development of a safe dexamethasone-eluting electrode array for cochlear implantation

Abstract

The dexamethasone doses used were safe in the guinea pig cochlea. Dexamethasone did not inhibit formation of a cochleostomy seal. The level of hearing protection afforded by dexamethasone eluting from an intracochlear array may depend upon the degree of elution and level of trauma inflicted.

Effects of Round Window Opening Size and Moisturized Electrodes on Intracochlear Pressure Related to the Insertion of a Cochlear Implant Electrode

“…Electrode surfacing was observed so far either to decrease insertion forces by lubricants applied [Kontorinis et al, 2011] or to carry neuroprotective substances into the cochlea via the electrode array [Stathopoulos et al, 2014]. In our model experiments, the contact of a hydrophobic silicon electrode array with the intracochlear fluid led to measureable pressure changes inside the cochlea.…”

Long-Term in vivo Release Profile of Dexamethasone-Loaded Silicone Rods Implanted Into the Cochlea of Guinea Pigs

“…However, due to the fast clearance of glucocorticoids in the inner ear fluid spaces achieving constant drug levels over a certain time period in local application is only feasible with sustained administration of the drug (38,39). Taken together, these data strongly support the approach that uses the electrode carrier as a drug reservoir to realize long-term intracochlear corticosteroid application to the inner ear over the course of several weeks after implantation (40,41).…”

Endolymphatic hydrops is prevalent in the first weeks following cochlear implantation

“…Steroids have failed to reduce fibrosis when injected directly into the inner ear (Huang et al, 2007), or applied locally to the round window (James et al, 2008;Lee et al, 2013). Steroid eluting arrays have produced mixed results (Stathopoulos et al, 2014;Wrzeszcz et al, 2015). We suggest this might be because none of these strategies would influence clot formation.…”