Application of MRI and intraoperative CT fusion images with integrated neuronavigation in percutaneous radiofrequency trigeminal rhizotomy.

Abstract

Percutaneous radiofrequency trigeminal rhizotomy (RF-TR) has been an effective treatment modality for medically refractory trigeminal neuralgia. Our group has established a protocol for this procedure that includes intraoperative computed tomography (iCT) navigation. The depth of the puncture needle in our protocol was based on cadaveric studies, and anatomical localization was mainly by electric stimulation test. The limitation of the invisibility of the trigeminal cistern on CT imaging and bias from the patient's subjective expression during neurophysiologic stimulation might affect the accuracy of the needle tip and the treatment effect.This study aimed to evaluate the feasibility and preliminary results of the application of magnetic resonance imaging (MRI) and iCT fusion imaging in RF-TR. The study included 13 patients who received RF-TR with iCT navigation and with recurrence within 3 years. Repeated RF-TR was performed with real-time guidance by MRI and iCT fusion imaging. A pain-free or partial satisfactory response was reported with 12 patients (92 %). There was a statistically significant difference in the depth of the needle tip before and after application of MRI and iCT fusion imaging. This preliminary study demonstrated that the application of MRI and iCT fusion could help with anatomical localization of the trigeminal cistern intraoperatively. The improvement in neuronavigation provides a choice in the treatment of recurrent or persistent trigeminal neuralgia after previous intervention. Long-term follow-up of the result is necessary to evaluate the benefit in terms of durability of therapeutic efficacy.