Protecting against electrode insertion trauma using dexamethasone

Objective: To compare the benefits of a dexamethasone-eluting array for hearing preservation and cochlear histopathology in low trauma (soft-surgery) and high trauma models of cochlear implant surgery.Methods: Adult guinea pigs were implanted with an intra-cochlear array using two different surgical procedures: either a soft-surgery approach or following generation of electrode insertion trauma (high trauma). Two methods of dexamethasone delivery were evaluated: elution from an electrode array alone, and elution from a cochlear implant electrode array in combination with a pre-operative systemic injection. All electrode arrays were implanted for a period of 4 weeks. Outcome measures at 4 weeks post-implantation included auditory brainstem response (ABR) thresholds, histological analysis of spiral ganglion neuron density, fibrotic tissue, new bone growth, and cochlear damage.Results: Animals exposed to high surgical trauma showed greater hearing loss than those in the low trauma model, irrespective of the ...