Ex Vivo Evaluation of a Minimally Invasive Approach for Cochlear Implant Surgery

Area of Science:

• Neurosurgery
• Medical Devices
• Otolaryngology

Background:

• Minimally invasive inner ear access for cochlear implant (CI) surgery presents significant surgical challenges.
• Computer-assisted surgical systems offer potential solutions to enhance precision and safety.

Purpose of the Study:

• To design and experimentally evaluate a novel micro-stereotactic targeting system for cochlear implant surgery.
• To assess the system's accuracy and feasibility for minimally invasive posterior tympanotomy.

Main Methods:

• A reusable, bone-anchored reference frame and a patient-specific drilling jig were developed.
• The system was tested on twelve human cadaver donors using cone beam computed tomography (CBCT) for trajectory planning.
• Drilling was performed manually, guided by the jig, targeting the cochlea's basal part.

Main Results:

• The system successfully enabled drilling with preservation of the facial nerve in all specimens.
• The mean system error at the cochlear target was 0.30 mm ± 0.11 mm.
• The accuracy of counterboring the guiding aperture into the jig was 0.09 mm ± 0.03 mm.

Conclusions:

• The proposed micro-stereotactic targeting system is feasible for minimally invasive posterior tympanotomy in cochlear implant surgery.
• The system demonstrated sufficient accuracy in ex vivo evaluations.
• This study provides the first comprehensive evaluation of the system's concept and performance.