Stereotactic Frame-Based Electrode Insertion: The Accuracy of Increasingly Oblique Insertion Angles.

Area of Science:

• Neurosurgery
• Medical Devices
• Epilepsy Treatment

Background:

• Stereotactic electrode placement is crucial for treating drug-resistant epilepsy.
• The Cosman-Roberts-Wells (CRW) frame is a common tool for intracranial electrode implantation.
• Understanding the impact of planned angles on electrode accuracy is essential for surgical planning.

Purpose of the Study:

• To evaluate the relationship between planned drill approach angle and the actual angular deviation of stereotactically placed intracranial electrodes.
• To determine if the magnitude of the planned angle affects the accuracy of electrode tip placement.

Main Methods:

• Stereotactic electrode implantation in 13 patients with drug-resistant epilepsy (136 electrodes total).
• Electrode targets planned on MRI; implantation via CRW frame with Ad-Tech drill guide and electrodes.
• Post-operative CT scans used to measure actual electrode angles (axial, coronal, sagittal) and compare with planned angles via Bland-Altman plots and linear regression.

Main Results:

• Linear relationships observed between planned and actual electrode angles across axial, coronal, and sagittal planes.
• No significant angular deflection was detected for any planned angle magnitude.
• The Ad-Tech drill guide and electrodes, used with the CRW frame, demonstrated consistent performance.

Conclusions:

• The planned drill approach angle does not significantly impact the accuracy of CRW frame-based stereotactic electrode placement.
• Oblique electrode insertion is a safe and accurate neurosurgical procedure.
• Findings support the use of varied planned angles for optimal electrode targeting in epilepsy surgery.