Can Electrocochleography Help Preserve Hearing After Cochlear Implantation With Full Electrode Insertion?

Area of Science:

• Otolaryngology
• Neurosurgery
• Audiology

Background:

• Cochlear implant (CI) surgery aims to restore hearing in individuals with severe to profound sensorineural hearing loss.
• Hearing preservation after CI surgery is a critical factor influencing patient outcomes and device benefit.
• Intracochlear electrocochleography (ECochG) is a technique that measures electrical potentials within the cochlea.

Purpose of the Study:

• To evaluate the effectiveness of intraoperative intracochlear electrocochleography (ECochG) monitoring in preserving hearing after cochlear implant (CI) surgery.
• To determine if real-time ECochG feedback during electrode insertion impacts postoperative hearing outcomes.

Main Methods:

• A prospective, randomized clinical trial was conducted across ten high-volume CI centers.
• Adult patients received cochlear implants, randomized to either surgery with audible ECochG monitoring or without.
• Hearing preservation was assessed by comparing pre- and post-operative low-frequency pure-tone averages (LF-PTA); electrode position was verified by CT scans.

Main Results:

• Eighty-five adult patients were enrolled; 43% experienced poor hearing preservation (LF-PTA change ≥30 dB).
• There was no significant difference in LF-PTA change between the ECochG-on group (27 dB) and the ECochG-off group (27 dB) (p = 0.89).
• Electrode translocation occurred in 7% of patients, exclusively in the ECochG-off group.

Conclusions:

• Intracochlear ECochG monitoring during CI surgery demonstrates prognostic utility.
• However, this study did not find significantly improved hearing preservation in patients randomized to ECochG monitoring compared to those without.