A Single Intratympanic Triamcinolone Acetonide Administration Elicits Long-Term Reduction in Impedances Following...

Area of Science:

• Otolaryngology
• Neurosurgery
• Biomedical Engineering

Background:

• Intracochlear fibrosis and inflammation are significant challenges in cochlear implantation (CI).
• Glucocorticoids are commonly used to manage post-CI inflammatory responses.
• This study evaluates the long-term impact of intratympanic triamcinolone acetonide on intracochlear impedance.

Purpose of the Study:

• To investigate the long-term effects of intratympanic triamcinolone acetonide suspension on intracochlear impedance changes in CI recipients.
• To compare the efficacy of different drug concentrations (10 vs. 40 mg/ml) and injection time points (1 vs. 24 hours prior to CI).

Main Methods:

• Eighty-seven patients undergoing CI were included; 39 received intratympanic triamcinolone acetonide, and 48 served as controls.
• Triamcinolone acetonide was administered at 10 or 40 mg/ml, 1 or 24 hours before surgery.
• Electrode impedances were measured and compared for up to 3 years post-implantation.

Main Results:

• Preoperative triamcinolone acetonide significantly reduced mean electrode impedances at first fitting compared to controls (P=.0001).
• Sustained impedance reduction was observed for up to 3 months, with significant improvements in middle and basal cochlear regions over 24 and 6 months, respectively.
• Higher drug concentration (40 mg/ml) and a 24-hour pre-operative interval resulted in lower impedances than 10 mg/ml and a 1-hour interval.

Conclusions:

• A single preoperative intratympanic injection of triamcinolone acetonide effectively reduces electrode impedances throughout the cochlea.
• The impedance-lowering effect persists for up to 2 years, after which impedances gradually equalize.
• This approach may attenuate the immediate tissue response following cochlear implantation.