Incidence of Trans-Impedance Matrix Pattern Variants in Patients With Normal Anatomy Receiving Cochlear Implantation

Area of Science:

• Otolaryngology
• Biomedical Engineering
• Neurosurgery

Background:

• Transimpedance (TIM) heatmap patterns can indicate cochlear implant electrode integrity.
• Understanding TIM pattern variants is crucial for assessing cochlear implant outcomes.

Purpose of the Study:

• To apply a transimpedance (TIM) heatmap classification scheme in patients with normal cochlear anatomy and in revision cochlear implant (CI) cases.
• To determine the incidence of TIM pattern variants and their clinical implications in these cohorts.

Main Methods:

• A single-center retrospective review of 321 cochlear implantations (CI) between June 2020 and June 2024.
• TIM heatmap patterns were analyzed intraoperatively in patients with normal cochlear anatomy and in a separate cohort undergoing revision surgery.
• TIM patterns were correlated with intraoperative X-ray findings of electrode position.

Main Results:

• Of 321 implants, 310 were primary surgeries and 11 were revision surgeries.
• 86.4% of primary CI surgeries showed normal TIM heatmaps, while only 45.5% of revision surgeries did.
• One revision case presented a novel 'double X' TIM pattern, which corresponded to a normal electrode position.

Conclusions:

• A decreased incidence of transimpedance (TIM) heatmap pattern variants occurs in cochlear implant (CI) recipients with normal cochlear anatomy.
• TIM heatmap analysis may offer insights into electrode function, particularly in revision CI scenarios.