Side slit guide pipe for precise placement of depth electrodes.

BACKGROUND: Using a stereotaxic technique, surgeons can accurately place a depth electrode (DE), but sometimes the DE deviates from the intended target due to movement of the electrode or leakage of cerebrospinal fluid when placing the electrode. If DEs can be anchored before removing the catheter insertion guide pipe, more accurate placement may be possible.

METHODS: We made a side slit guide pipe. When the DEs were anchored to the dura or the edge of the burr hole, the DE did not move when the guide pipe was removed. We measured the distance between the planned target and the tip of the electrode in eight patients with medically intractable epilepsy who underwent DE placement with stereotactic neuronavigation guidance (3 females, 10 males; 7 to 43 years old; mean, 23.0 years; median, 27 years).

RESULTS: Thirty DEs were implanted. The distance from the planned target to the tip of the DE ranged from 0.3 to 1.2 mm (mean, 0.570 mm; median, 0.5 mm; standard deviation, 0.212). The distance from the planned target to the tip of the DE with dural anchoring was 0.467 mm (range, 0.3 to 0.6 mm; mean, 0.467 mm; median, 0.45 mm; standard deviation, 0.121), and with burr hole edge anchoring was 0.596 mm (range, 0.3 to 1.2 mm; mean, 0.596 mm; median, 0.50 mm; standard deviation, 0.224; p = 0.205).

CONCLUSION: DEs can be anchored using the side slit guide pipe for more precise placement.