Challenges and Solutions in SEEG Using the Leksell Vantage Frame

Overview

Stereo-electroencephalography (SEEG) with the Leksell Vantage frame presents unique challenges related to frame setup and trajectory planning, especially for temporal and complex extratemporal targets. A preoperative planning routine addressing frame restrictions can optimize electrode placement, reduce intraoperative adjustments, and enhance procedural safety and efficiency.

Background

SEEG is an invasive technique used to localize seizure onset zones in patients with pharmaco-resistant epilepsy, supplementing non-invasive EEG. It involves stereotactic implantation of depth electrodes, typically using frames like the Leksell Vantage or ZD Inomed. Accurate planning of electrode trajectories is critical to avoid vascular injury, minimize electrode deviation, and ensure coverage of suspected epileptogenic regions, including complex extratemporal areas such as the insula. The Leksell Vantage frame, introduced in 2018, is a lightweight, MRI-compatible system designed to improve stereotactic accuracy and safety.

Data Highlights

Typical SEEG procedures use 6–15 electrodes with 5–18 contacts each, spaced 2–5 mm apart and 0.86 mm in diameter. The risk of clinically relevant hemorrhage is approximately 1%, with trajectories planned to avoid sulci and vascular structures. The Leksell Vantage frame allows for multiple adjustments including y-axis orientation, z-axis ring direction, arc-angle, and x-coordinate to accommodate electrode trajectories, though improper alignment can limit instrument positioning and require intraoperative trajectory changes.

Key Findings

• SEEG electrode implantation requires interdisciplinary planning using 3D MRI and CT angiography to delineate safe, avascular trajectories.
• The Leksell Vantage frame offers MRI compatibility and lighter weight but imposes spatial constraints that can conflict with optimal electrode entry points, especially for temporal lobe targets.
• Frame setup parameters such as y-axis orientation, z-axis ring direction, arc-angle, and x-coordinate critically influence electrode trajectory feasibility and instrument accessibility.
• Preoperative planning routines that consider frame limitations can prevent intraoperative trajectory adjustments, reducing operating time and enhancing safety.
• Electrode trajectories should ideally be perpendicular to the skull to minimize deviation, avoid sulci and vessels to reduce hemorrhage risk, and consider cosmetic and pressure point factors for entry site selection.
• Use of bone anchors and precise measurement of insertion angles and bone thickness via imaging are essential for stable and accurate electrode placement.

Clinical Implications

Clinicians performing SEEG with the Leksell Vantage frame should incorporate detailed preoperative planning that accounts for frame-specific spatial constraints to optimize electrode trajectories. Awareness of frame setup parameters and their impact on instrument positioning can prevent intraoperative adjustments, reduce operative time, and minimize complications such as hemorrhage. Multidisciplinary collaboration and use of advanced imaging for trajectory planning remain essential for safe and effective SEEG implantation.

Conclusion

The Leksell Vantage frame enhances SEEG procedures through MRI compatibility and improved ergonomics but requires careful preoperative planning to navigate its spatial limitations. Tailored planning protocols can ensure safe, accurate electrode placement and improve surgical outcomes in complex epilepsy cases.

References

1. Mullin et al. 2021 -- Systematic review of SEEG hemorrhage risk
2. Vakharia et al. 2020 -- Meta-analysis of SEEG placement techniques
3. Elekta 2018 -- Leksell Vantage Stereotactic System