Accuracy and Feasibility Analysis of SEEG Electrode Implantation using the VarioGuide Frameless Navigation System in Patients with Drug-Resistant Epilepsy.

OBJECTIVE: The objective of the study was to evaluate the feasibility and accuracy of frameless stereoelectroencephalography (SEEG) electrode implantation in patients with drug-resistant epilepsy using the VarioGuide system. METHODS: The VarioGuide frameless navigation system was used to implant SEEG electrodes in patients with medically drug-resistant epilepsy. Demographic data, surgery duration, number of electrodes, and complications were retrospectively analyzed. Accuracy was compared by measuring the distance between the planned and actual electrode positions as determined by postoperative computed tomography images. RESULTS: A total of 141 SEEG electrodes were implanted in 19 patients from May 2015 to December 2018 with an average of 7.42 (range: 4-10) leads per patient. The average entry point localization error (EPLE) was 1.96 ± 0.47 mm (range: 0.32-3.29) and average target point localization error (TPLE) was 2.47 ± 0.79 mm (range: 0.72-4.83). The average operating time per lead (OTPL) was 14.16 ± 2.68 minutes (range: 8.64-21.58). No complications occurred. CONCLUSION: The VarioGuide frameless navigation system can be an effective method for SEEG electrode implantation in patients with drug-resistant epilepsy, particularly when the electrodes are concentrated in a relatively small region and the number of implanted electrodes is small.