Forces and trauma associated with minimally invasive image-guided cochlear implantation

Area of Science:

• Otorhinolaryngology
• Neurosurgery
• Medical Engineering

Background:

• Minimally invasive image-guided cochlear implantation (CI) offers a precise approach to the cochlea.
• Patient-customized microstereotactic frames facilitate single drill-pass access.
• Understanding insertion forces and potential trauma is crucial for electrode placement.

Purpose of the Study:

• To investigate the average insertion force and associated trauma of lateral wall CI electrodes.
• To evaluate the efficacy of a minimally invasive, image-guided CI technique.

Main Methods:

• Utilized 6 fresh cadaveric temporal bones with CT-guided microstereotactic frames.
• Manually inserted lateral wall CI electrodes via a drilled tunnel using surgical forceps.
• Recorded insertion forces with a 6-axis load sensor.
• Performed histological analysis of the otic capsule and intracochlear tissues.

Main Results:

• Successful cochlear access was achieved in all specimens.
• Average insertion forces ranged from 0.009 to 0.078 N, with peak forces up to 0.469 N.
• Histology revealed no identifiable intracochlear trauma, with deep insertions achieved (360°–600°).

Conclusions:

• Minimally invasive image-guided CI with lateral wall electrodes shows insertion forces comparable to traditional methods.
• The technique allows for deep electrode insertion without significant trauma.
• This approach holds promise for improving CI surgical outcomes.