[A study of the relations of foramen rotundum structure direction and the approach of percutaneous puncturing of radiofrequency thermocoagulation for treating V2 of primary trigeminal neuralgia].

Objective: To investigate the relations of foramen rotundum structure direction and surrounding structure systematically in order to choose the best approach of percutaneous puncturing of radiofrequency thermocoagulation for treating V2 of primary trigeminal neuralgia. Methods: A total of 122 patients with V2 of primary trigeminal neuralgia for radiofrequency thermocoagulation were enrolled from August 2012 to May 2017 at the First Hospital of Jiaxing. CT scan images were observed retrospectively, to find the inside and outside of the foramen rotundum. The direction of foramen rotundum were recorded and the best approach of puncturing were analyzed. Results: The images were divided into four quadrants with the semi - coronal CT scan plane of the lower margin of the zygomatic arch and the outer edge of foramen rotundum for horizontal axis, and the sagittal plane for the vertical axis. In 122 cases, foramen rotundum direction in outer upper quadrant were 77 cases(63.1%), and in outer under quadrant were 22 cases(18.0%), and in inner upper quadrant were 19 cases(15.6%), and in inner under quadrant were 4 cases(3.3%). Conclusion: The most common foramen rotundum direction is in outer upper quadrant, so the best approach of percutaneous puncturing of radiofrequency thermocoagulation for treating V2 of primary trigeminal neuralgia is the upper side against zygomatic and the inner side against the wall of maxillary sinus.