Dose-Dependent Transient Decrease of Impedances by Deep Intracochlear Injection of Triamcinolone With a Cochlear...

Area of Science:

• Otolaryngology
• Biomedical Engineering
• Neurosurgery

Background:

• Electrode impedances in cochlear implants can affect device performance.
• Previous low-dose steroid applications via cochlear catheter did not achieve long-term impedance reduction.

Purpose of the Study:

• To investigate the effect of high-dose intra-cochlear triamcinolone on electrode impedances in cochlear implant recipients.
• To determine if a dose-dependent reduction in impedances could be achieved.

Main Methods:

• Patients received either low-dose (4 mg/ml) or high-dose (20 mg/ml) triamcinolone via cochlear catheter before Med-El Flex28 electrode insertion.
• Impedances were measured intra-operatively up to 12 months post-fitting.
• Results were compared to a control group without steroid application.

Main Results:

• High-dose triamcinolone significantly reduced initial electrode impedances compared to controls.
• Low-dose triamcinolone did not show a significant impedance reduction at first fitting.
• Impedance reduction was significant at basal and medial electrode contacts but not permanent, with no differences at later time points.

Conclusions:

• This study demonstrates a dose-dependent impedance reduction with high-dose intra-cochlear triamcinolone injection prior to cochlear implantation.
• A single high-dose application can significantly reduce impedances up to the first fitting.
• The observed impedance reduction effect is not permanent.