Surgical Technique for Repositioning Deep Brain Stimulation Electrodes

Accuracy in deep brain stimulation (DBS) surgery is critical. The literature lacks a systematic approach, including surgical technique, for repositioning DBS electrodes when first pass accuracy is suboptimal. This is especially true of "asleep" DBS surgery.

A retrospective analysis was performed for DBS with an image-guided image-verified robotic technique performed from July 2018 to November 2024. Surgical technique for repositioning was based on the direction and magnitude of the first pass radial error. Radial error was measured as distance (mm) in the plane perpendicular to the planned trajectory from the center of the electrode on intraoperative O-arm computed tomography to the planned trajectory.

We analyzed 506 passes for 441 electrodes. Final radial error after repositioning (0.96 ± 0.38 mm) was comparable with previous reports (0.9 mm). An average 1.14 ± 0.51 passes per electrode was similar to literature values for asleep cases (1.4 passes). Average radial error from trajectory 1 to electrode 1 was 2.39 mm and for trajectory 2 to electrode 2 was 2.23 mm, with a significant correlation between the 2 passes (Pearson r = 0.68, P < .001). Direction of radial error was identical from pass 1 to pass 2 in 71.74% of revisions. The relationship between the direction of the initial radial error and subsequent error was statistically significant (χ 2 statistic 45.04, P < .001). This did not differ with or without the use of a rigid cannula ( U -statistic: 77.0, P = .46) and did not depend on the presence of pneumocephalus (Pearson correlation coefficient 0.008, P = .96).

For DBS electrodes placed with suboptimal radial error, direction and magnitude of that error can be reliably used to correct that error. This error is likely due to a reproducible systematic error influenced by both procedural variables and patient-specific anatomical factors.