Positioning technology in trigeminal notch in treatment of primary trigeminal neuralgia

Abstract

Objective To study the ovale or trigeminal notch positioning and puncture techniques using thin slice CT scan in treatment of trigeminal neuralgia through radiofrequency thermocoagulation, and analyze its efficacy. Methods The clinical data of 43 patients with primary trigeminal neuralgia, admitted to our hospital from August 2009 to September 2012, were retrospectively analyzed. According to the positioning marks, two groups were divided. Both group A (n=21) and group B (n=22) adopted Hartel anterior approach; puncture in group A was through foramen ovale, adjusting the direction and depth of the puncture needle, observing the patient's response to electrical stimulation, and damaging the sensory fiber; puncture in B group was through trigeminal gasserian ganglion notch, damaging neurons through radiofrequency thermocoagulation. Transverse and longitudinal positioning was performed in the two groups, and mandibular neuralgia, maxillary neuralgia and ophthalmic neuralgia were located in the trigeminal notch from outside to inside, and the longitudinal location targeted in the trigeminal notch bone surface in front of 5 mm. The puncturing time, puncturing success rate and complications rate between the two groups were recorded. The visual analog scale (VAS) was scored, respectively, one d, and one, 6, 12 and 24 months after the surgery. The outcome responses of pain relief were evaluated. Results The puncture success rate in both two groups was 100%; the puncturing time in group A ([5.0±0.4] min) was significantly shorter than that in group B ([12.0±0.7] min, P<0.05); the puncturing complication rate in group A (4.8%) was significantly lower than that in group B (13.6%, P<0.05), but the complication rate of radiofrequency in group A was significantly higher than that in group B (involving normal nervi trigeminus branches: 42.9% vs. 13.6%, involving motor fibers: 14.3% vs. 4.5%, P<0.05). The treatment effect of group B was better than that group A 12 and 24 months after surgery (P<0.05). Conclusions A new method of radiofrequency thermocoagulation targeted pathogenic neurons in trigeminal notch owes more advantages, including low complication rate caused by radiofrequency thermocoagulationa, high target selectivity and low recurrence rate. However, its technical requirement is high. Key words: Foramen ovale; Trigeminal notch; Trigeminal neuralgia; Radiofrequency thermocoagulation