Minimally invasive surgical techniques in vestibular function preservation in patients with cochlear implants

Area of Science:

• Otolaryngology
• Neuroscience
• Audiology

Background:

• Cochlear implantation (CI) effectively treats severe-to-profound sensorineural hearing loss (SNHL).
• CI surgery carries a risk of vestibular damage, but advancements aim for hearing preservation (HP) and reduced vestibular impact.
• Systematic studies on vestibular function changes after minimally invasive CI at various follow-ups are limited.

Purpose of the Study:

• To systematically investigate short- and long-term changes in vestibular function after minimally invasive CI surgery.
• To assess vestibular function recovery and potential damage across different time points post-implantation.

Main Methods:

• Retrospective study of 72 patients with bilateral SNHL and pre-operative residual hearing undergoing unilateral minimally invasive CI.
• Longitudinal vestibular function testing (caloric, cVEMP, oVEMP, vHIT) at 5 days pre-op and 1, 3, 6, 9, 12 months post-op.
• Comparison of vestibular test failure rates between implanted and non-implanted sides and across different follow-up intervals.

Main Results:

• Higher caloric and oVEMP failure rates than vHIT were observed at 1, 3, and 9 months post-op.
• No significant differences in failure rates among vestibular tests were found at 6 and 12 months.
• Vestibular function showed a trend towards decreased failure rates over time, with similar patterns observed in early and late recovery stages.

Conclusions:

• Minimally invasive CI surgery generally preserves vestibular function, with no significant discrepancies among otolith and semicircular canal functions at 12 months.
• Vestibular function changes exhibit a consistent pattern during both early and late recovery phases after CI.
• The study highlights the potential for vestibular function preservation with modern CI surgical techniques.