We describe the use of custom-made, 3D-printed patient models in preoperative planning of robot-assisted depth electrode placement for epilepsy monitoring in twelve pediatric patients with 132 total electrodes.

Frameless stereotactic robotic technology has become increasingly ubiquitous since FDA approval of the Robotic Surgical Assistant (ROSA) in 2012. While use of the ROSA robot has greatly augmented stereotactic placement of intracranial depth electrodes for the purposes of epileptogenic focus identification, the preoperative planning stages remain limited to computer software.

Anatomically accurate, custom-made 3D models were created by our Center for 3D Design and Innovation before each case. In preoperative rehearsal sessions, each model was registered, positioned, and pinned using the ROSA platform. After standard software-based electrode trajectory planning, depth electrodes were placed in each 3D model with a focus on maximizing efficiency and minimizing intraoperative conflicts.

Utilization of the 3D-printed model enabled workflow optimization and early recognition of difficulties with patient positioning, registration, and electrode insertion. Average lead placement time during the real operation was six minutes per lead; we achieved these results without a single intraoperative trajectory change and without any registration errors/do-overs, postoperative complications, or electrode inaccuracies. In total, 132 electrodes were placed as follows: 37 temporal, 38 insular, 23 frontal, 17 cingulate, 10 parietal, and 7 occipital. The total production cost per model, including labor and parts, was $35.00 (USD). Considering the reduction in operative time provided by the increase in efficiency (45 minutes per case, on average), we estimate an overall cost savings of over $6500 per case.

Use of 3D-printed patient models greatly enhances presurgical positioning and trajectory planning in the placement of stereotactic depth electrodes for epilepsy monitoring in pediatric patients. The rehearsal session decreases operative time and increases efficiency of electrode placement, resulting in increased patient safety and cost-savings.