Percutaneous Trigeminal Rhizotomy Using a Custom Electromagnetic Neuronavigation-Compatible Cannula: Technical Note and Comparative Study

BACKGROUND AND OBJECTIVES: Trigeminal neuralgia causes debilitating facial pain. Treatments, including decompression, radiosurgery, and minimally invasive percutaneous procedures such as mechanical compression, are low risk and offer immediate relief, making them a preferred option. Successful percutaneous treatment depends on safely and successfully accessing the foramen ovale. This study evaluated a novel electromagnetic (EM)-guided cannula used for percutaneous trigeminal rhizotomy. METHODS: The cannula's accuracy and EM neuronavigation compatibility were evaluated in a cadaveric study. Subsequently, we evaluated a retrospective series of patients who underwent percutaneous trigeminal rhizotomy between June 2017 and April 2024 using either the novel cannula or a traditional method using fluoroscopic guidance. The exposure variables included preoperative characteristics, comorbidities, and intraoperative variables such as operation duration, balloon inflation time, and fluoroscopy exposure. Primary outcomes were pain relief, assessed using the Barrow Neurological Institute score for trigeminal neuralgia pain at immediate postoperative, 4-month, and last follow-up time points, and pain recurrence during follow-up. RESULTS: The cadaveric testing had a 100% cannulation success rate, with millimeter precision from the stylet to the center of the foramen ovale. A total of 61 percutaneous trigeminal rhizotomy procedures with a mean follow-up of 8.5 ± 9.9 months were studied. The EM navigation technique was used in 28 and conventional fluoroscopic guidance in 33. Fluoroscopy exposure time was significantly lower with EM navigation (1.3 ± 0.6 minutes vs 7.0 ± 3.8 minutes; P < .001). Multivariable regression analysis found no difference in patient outcomes between the 2 techniques. CONCLUSION: The EM-guided cannula may assist surgeons in performing trigeminal rhizotomies accurately and efficiently while also reducing operation time and radiation exposure.