News & Events
October 22, 2014
Growth factor-eluting cochlear implant electrode: impact on residual auditory function, insertional trauma, and fibrosis

Kikkawa et al. Journal of Translational Medicine 2014, 12:280

Cochlear implants (CIs) provide auditory perception to individuals with severe to profound sensorineural hearing loss by electrically stimulating spiral ganglion neurons (SGNs) via an electrode array implanted into the cochlea. Recent advances in CI technology have led to the development of a new generation of hearing-preserving CIs with less traumatic electrodes that minimize inner ear trauma during electrode insertion. This is particularly true for those with some residual hearing who may benefit from newly emerging stimulus strategies that employ a combination of electrical and acoustic stimulation. Moreover, insertional trauma can also lead to scar and fibrous tissue formation that could result in impedance increase and residual hearing decrease.

Two surgical strategies have been used to reduce insertional trauma: soft surgery and targeted drug delivery. However, even with the introduction of minimally traumatic “soft” surgical techniques and electrodes that have been modified to reduce intracochlear trauma during their insertion, residual hearing is lost or incompletely preserved in one-third of cases. Some researchers have begun to explore the possibility that better hearing preservation may be achieved by the application of protective pharmacological agents to the inner ear at the time of surgery.