CT-guided radiofrequency thermocoagulation of trigeminal nerve via foramen rotundum route: analysis of the three - dimensional puncture pathway and the influence factors / 介入放射学杂志

ABSTRACT

Objective Based on CT imaging measurements to investigate the relevant parameters of 3D positioning that are used for the puncturing of trigeminal nerve via foramen rotundum route, and to discuss the influences of gender, age, and BMI on the measurements of these parameters in order to improve the success rate of puncturing. Methods A total of 64 patients with trigeminal neuralgia (second branch), who were successfully treated with CT - guided radiofrequency thermocoagulation of trigeminal nerve via foramen rotundum route during the period from August 2015 to March 2017, were included in this study. Their CT images were retrospectively analyzed. The line from the opening of the external auditory canal to the root of the nose (ear-nose line) was used as the base line on sagittal plane, and the angle between the ear-nose line and the puncture needle (angle α) was measured. On transverse section drawing a line between the midpoint of nose bridge and the midpoint of the posterior edge of the ethmoid sinus (M line), the angle between M line and the puncture needle (angle β) was determined. The vertical distance from the midpoint of the foramen rotundum to M line(D1), the vertical distance from needle puncture point to M line(D2), and the puncture depth (D3) were respectively measured. Results The angle α varied from 44. 10° to 63. 50° with a mean of (55. 05°±5. 48°). The angle β ranged from 26. 42° to 68. 37° with an average of (38. 19°±8. 58°). The distance of D1 was (19. 55±2. 67) mm, the distance of D2 was (58. 50±5. 41) mm, and the depth of D3 was (64. 89+8. 21) mm. The gender, age and BMI value showed a close correlation with the puncture angle and the puncture depth (P＜0. 05), and no statistically significant differences in these indexes existed between the left side and the right side (P＞0. 05). Conclusion The angle a and the other puncture parameters can roughly determine the three dimensional spatial orientation of foramen rotundum, which can be further adjusted according to patient's gender, age and BMI value. (J Intervent Radiol, 2018, 27 234-237)