Intraoperative Visual Identification of Extra-Cochlear Electrodes in Cochlear Implantation Using Stimulation...

Area of Science:

• Otolaryngology
• Biomedical Engineering
• Neurosurgery

Background:

• Extra-cochlear electrodes (EEs) are a common complication in cochlear implant (CI) surgery, potentially impairing speech perception.
• Standard intraoperative monitoring tools often fail to detect misplaced electrodes accurately.

Purpose of the Study:

• To evaluate Stimulation Current-Induced Non-Stimulating Electrode Voltages (SCINSEVs) as a rapid and accurate intraoperative method for identifying EEs.
• To assess the clinical utility of SCINSEVs for enabling immediate surgical correction of misplaced electrodes.

Main Methods:

• A prospective intraoperative study involving adult CI candidates or users undergoing surgery.
• Electrical field imaging (EFI) measurements were recorded during electrode insertion, with surgeons intentionally placing a variable number of electrodes outside the cochlea.
• SCINSEVs data were analyzed by blinded expert reviewers to identify the number of EEs, with results correlated to visual confirmation and surgical outcomes.

Main Results:

• A significant correlation (r = 0.63, p < 0.0001) was found between the number of extra-cochlear electrodes and their detection via SCINSEVs.
• SCINSEVs achieved an overall sensitivity of 95.9% and a specificity of 40.7% for identifying the presence or absence of EEs.
• The method demonstrated effectiveness regardless of surgery type or simulated postoperative conditions (blood or fascia).

Conclusions:

• SCINSEVs provide a rapid, reliable, and non-radiative intraoperative tool for detecting extra-cochlear electrodes during cochlear implant surgery.
• This technique offers high sensitivity, enabling timely surgical correction and potentially improving CI outcomes.
• Clinical implementation and staff training for SCINSEVs are recommended to enhance surgical precision and patient results.