IMPROVING SAFETY AND EFFICACY OF RADIOFREQUENCY TRIGEMINAL RHIZOTOMY OF THE FORAMEN OVALE: PROCEDURAL TECHNIQUES TO OPTIMIZE TARGET LOCALIZATION AND CANNULATION
Study type: Retrospective, single center
Publication: Acta Neurochirurgica 2019; 161(7):1427-34 (Link to PubMed)
Key Words: Refractory TN – Foramen Ovale – Thermal RF and Image iCT-MRI fusion
To improve radiofrequency trigeminal rhizotomy (RF-TR) safety and precision by optimizing the visualization of the Trigeminal Cistern and Ganglion and by facilitating the localization of the RF lesion target (Foramen Ovale)
This study enrolled 252 consecutive patients diagnosed with refractory TN. These patients underwent a total of 340 RF-TN procedures.
Guidance: The target structure (FO) was visualized either on intraoperative Computed Tomography (iCT) or magnetic resonance images (MRI) and iCT fused images (Brainlab AG).
Clinical outcomes: Pain severity pre- and post-treatment and the occurrence of postoperative complications. Patients were followed up for 2-8 years via outpatient visits or phone interviews.
RF procedure: RF-TN was performed with a Tew electrode kit and a Radionics RTG-3CF generator. A sensory test was performed (50Hz; 1ms PW; 0-1V) before performing two consecutive RF lesions at 60-95°C for 100 seconds.
STUDY RESULTS AND CONCLUSIONS
- iCT with MRI fusion was significantly associated with a greater degree of immediate pain relief, and a higher likelihood of a sustained response lasting over two years (p<0.01).
- iCT with MRI fusion was also linked to a higher occurrence of CSF outflow; which is associated with better heat transfer and less tissue charring.
- Accurate anatomical localization of the FO using iCT-MRI image fusion could avoid puncture-related complications and provide sustained pain relief.