Individual Hearing Preservation Cochlear Implantation Using the Concept of Partial Insertion

Area of Science:

• Otolaryngology
• Audiology
• Neurosurgery

Background:

• High-frequency hearing loss affects many individuals, impacting speech comprehension.
• Electric-acoustic stimulation (EAS) offers a solution for patients with residual hearing.
• Partial electrode insertion is a technique explored for cochlear implantation.

Purpose of the Study:

• To evaluate the efficacy of partial insertion of flexible lateral wall electrodes in patients with residual hearing.
• To assess the potential for electric-acoustic stimulation (EAS) in these patients.
• To determine the impact on hearing preservation and speech understanding.

Main Methods:

• Six patients with high-frequency hearing loss underwent partial insertion of atraumatic lateral wall electrodes.
• Electrode lengths of 24mm and 28mm were used for targeted insertion depths of 16mm and 20mm, respectively.
• Pre- and postoperative pure tone thresholds, speech perception tests (Freiburg monosyllables, Hochmair-Desoyer sentence test), and cochlear imaging were analyzed.

Main Results:

• Residual hearing was preserved in all six patients and remained stable for up to six months.
• All patients successfully utilized EAS, achieving average speech understanding scores of 65% for monosyllables and 76% for sentences in noise.
• Significant benefits were observed compared to the preoperative best-aided condition.

Conclusions:

• Partial insertion of atraumatic lateral wall electrodes demonstrates good hearing preservation rates.
• This technique yields very good speech perception results in electric-acoustic stimulation (EAS).
• Partial insertion offers an individualized approach to cochlear implantation, allowing for future electrode advancement if needed.