Robot-Assisted Placement of Convection-Enhanced Delivery Infusion Cannulas

Indications for convective delivery of putative therapeutics are rapidly expanding. Cerebellar targets, such as the dentate nucleus, will be crucial to target in certain conditions. Current skull-mounted, magnetic resonance (MR) imaging-compatible platforms preclude infratentorial approach to cerebellar targets. We assessed the feasibility, effectiveness, and accuracy of computed tomography (CT) and MR imaging guided, robot-assisted placement of convection enhanced delivery (CED) cannulas.

Cadaveric (n = 5) specimens underwent preoperative CT and MR-imaging for trajectory and target (bilateral dentate nuclei) planning followed by robot-assisted placement of suboccipital cannulas (n = 10). Placement accuracy was assessed using CT and MR-imaging.

All cadaveric (3 female, 2 male) specimens underwent successful suboccipital placement of bilateral CED cannulas to the dentate nuclei along defined trajectories. Mean incision to cannula placement time was 22 ± 0.6 minutes (range, 13-35 minutes). Medial-lateral error was 1.2 ± 1.1 mm (range, 0.1-3.6 mm), rostral-caudal error was 1.0 ± 0.6 mm (range, 0.1-2.1 mm), and depth error was 0.7 ± 0.4 mm (range, 0.2-1.5 mm) on CT. Mean medial-lateral error was 1.4 ± 0.9 mm (range, 0.1-2.8 mm), rostral-caudal error was 0.9 ± 0.5 mm (range, 0.3-1.8 mm), and depth error was 0.9 ± 0.6 mm (range, 0.1-2.0 mm) on MR imaging. CT accuracy errors were analogous to MR imaging errors (t-test, P ≥ .3).

Image-guided, robot-assisted placement of CED cannulas is feasible, accurate, and efficient. This paradigm can provide advantages in placing convective infusion cannulas compared with existing methods.