Electrode Afterload: A Valuable Technique in a Case of Short Electrode Insertion

Area of Science:

• Otolaryngology
• Neurosurgery
• Audiology

Background:

• Electrode position in the cochlea is crucial for speech performance.
• Factors like array length, insertion depth, and anatomy influence intracochlear electrode placement.
• Deep insertions (>20 mm) and revision surgeries pose risks to residual hearing and electrode integrity.

Observation:

• A 73-year-old female patient with hearing loss underwent multiple surgeries for cholesteatoma, followed by cochlear implant (CI) surgery.
• Poor speech understanding post-CI led to revision surgery, revealing the electrode's initial marker at 20 mm.
• The electrode was advanced an additional 4 mm deeper into the cochlea.

Findings:

• Speech perception improved significantly, reaching 25% at six months and 45% at twelve months post-revision, as measured by the Freiburger monosyllabic speech test.
• Hearing preservation was achieved despite the deeper insertion (to 24 mm).
• A partially obliterated open cavity facilitated surgical access for the deeper insertion.

Implications:

• Revisional deeper insertion of cochlear implant electrodes is feasible and can enhance speech understanding while preserving hearing.
• This technique challenges the assumption that deeper insertions inherently risk hearing loss.
• Careful surgical planning and execution are vital, especially in revision cases, to optimize outcomes and minimize iatrogenic risks.