Subscribe to RSS
Dose dependent decrease of impedances after Cochlea Implantation by injection of triamcinolone via cochlea catheter
18 April 2018 (online)
Triggered by the insertion trauma, connective tissue develops around the electrode. The postoperatively measurable impedances seem to correlate with the extent and can be used for interpreting measures to curb this. Previous publications have demonstrated a positive effect of triamcinolone, at least in basal areas, when injected into the round window prior to insertion. In order to achieve this reduction of impedances even in apical areas, a catheter for intracochlear pharmacotherapies has been developed together with Med-El (Innsbruck, Austria).
The catheter consists of a 20 mm long, hollow silicone tube with the dimensions of a standard electrode with an outlet for liquids at the top. In each case, 5 patients without functional residual hearing (> 80 dB hearing loss at 250 Hz) were treated with triamcinolone (low dose: 4 mg/ml vs. high dose: 20 mg/ml) with a cochlear catheter before implantation with a Med-El Flex 28 electrode. Impedances, electric evoked compound action potentials and amplitude growth function were measured intraoperatively and at defined intervals after implantation and compared with a control group of patients with the same electrode, similar residual hearing but without catheter application.
There were no adverse events during and after the intervention. While in the low dose group the impedances decreased only in the first weeks compared to the control group, the effect in the high dose group was detectable both basal and apical beyond first fitting. 3 and 6 month data will be presented.
The investigated method seems suitable as a safe and effective form of drug delivery even for apical areas of the cochlea.