The use of multiplanar trajectory planning in the stereotactic placement of depth electrodes.

OBJECTIVE: To assess the value of multiplanar reconstruction software in trajectory planning for depth electrode insertion in medically refractory epilepsy.
METHODS: A series of 29 patients undergoing frame-based hippocampal depth electrode insertion were identified. In 19 patients, preoperative trajectory planning was conducted in axial, coronal, and sagittal planes using standard-axis software. In 10 patients, preoperative trajectory planning was conducted with multiplanar reconstruction software. Postoperative magnetic resonance imaging scans were evaluated to study the quality of insertion. Target accuracy was assessed by measuring the mean shortest distance to strictly defined hippocampal borders in the coronal plane ("coronal deviation"). Additionally, the number of electrode contacts placed within the amygdalohippocampal structure was assessed.
RESULTS: With the use of multiplanar reconstruction software, there was a statistically insignificant increase in coronal deviation (standard-axis software group, 0.09 +/- 0.50 mm; multiplanar reconstruction group, 0.37 +/- 1.16 mm). However, the use of multiplanar planning strategies resulted in approximately one additional electrode contact inserted in the amygdalohippocampal structure (standard-axis software group, 3.42 +/- 0.89; multiplanar reconstruction group, 4.36 +/- 0.93; P < 0.01).
CONCLUSION: The use of reconstructed planes in preoperative trajectory planning allows for the insertion of additional electrode contacts within the target structure.