Robotic keyhole access to the semicircular canals for vestibular implantation: an anatomical feasibility study

Vestibular implants are a promising treatment for patients with severe bilateral vestibulopathy. However, precise and minimally invasive access to the semicircular canals remains a key surgical challenge.

To evaluate the anatomical feasibility of robotic keyhole access to the three semicircular canals for vestibular implantation using image-guided drilling.

High-resolution computed tomography scans from 30 ears were analyzed to simulate drill trajectories to the superior, lateral, and posterior semicircular canals. Trajectories were evaluated for surgical accessibility, safety margins relative to critical structures, and approach angles suitable for electrode insertion. Mutually optimized entry points within a simple cortical mastoidectomy were identified.

Safe access to the three canals was feasible in all cases. The lateral and posterior canals were consistently accessible at favorable semicircular canal entry angles. The superior canal required steeper semicircular canal entry angles but remained within acceptable limits. In all cases, three suitable trajectories could be planned to originate from a single 15 mm retroauricular mastoidectomy region.

Robotic keyhole access to the semicircular canals is anatomically feasible across a range of patient anatomies. These findings support the clinical potential of minimally invasive, image-guided vestibular implantation.