Cochlear implantation through intracochlear fibrosis: A comparison of surgical techniques.

Abstract

Objective: While the implications of ossification on cochlear implantation (CI) have been extensively described, there is a paucity of data regarding the fibrotic stage. We examined the outcomes of different insertion techniques for managing intracochlear fibrosis.

Study design: Retrospective review of case series with case-control comparison.

Setting: University-based tertiary-referral otology-neurotology practice.

Patients: Between 2009 to 2020, 384 patients underwent CI. Of those, 7 patients (8 ears) demonstrated intracochlear fibrosis.

Interventions: CI performed 1-4 months following meningitis/labyrinthitis and 12-24 months after idiopathic sudden SNHL. Fibrosis removal (38%) or dilation (63%) permitted implantation. A styleted-electrode was used in 63% due to dense fibrosis.

Main outcome measures: Postoperative audiometry with CI in place, additional comparisons with audiometric outcomes in age-matched controls.

Results: Full insertion achieved in all except one ear with partial ossification. Mean ipsilateral pure tone average (PTA) improved to 29 ± 15 dB and speech discrimination to 72 ± 28%. Fibrosis removal vs. dilation resulted in no PTA differences (p = 0.76). Poorest outcomes occurred with the longest time to surgery.

Conclusions: Good CI audiologic outcomes in the setting of cochlear fibrosis can be achieved and are independent of technique. Instead, they vary with time to implantation. Every attempt should be made to intervene as early as possible.