ABSTRACT
Objective:To investigate specificity of neurovascular compression in patients with primary trigeminal neuralgia (PTN) by three-dimension reconstruction and computational fluid dynamics.Methods:Clinical characteristics and preoperative magnetic resonance imaging (MRI) data of 20 patients with both PTN and single artery compression (PTN group) and 10 patients without PTN but having neurovascular contact in MRI images (control group) in the Second Affiliated Hospital of Zhengzhou University from January 2018 to December 2019 were collected and analyzed. After three-dimension reconstruction of the MRI images, curvature of the arterial loop, angle between the plane of arterial loop and the trigeminal nerve and location of the compression were observed. Then bidirectional structure-fluid coupling based on the optimized stereolithography models of arterial loop and nerve were processed by ANSYS 19.2 software. In the location of the compression of contact, equivalent stress (ES) of arterial loop on the nerve, shearing stress (SS) of the blood flow and local deformation of the nerve were iteratively computed. All parameters were analyzed and compared between the PTN group and the control group, and the correlation analysis was proceeded between the anatomical parameters and hemodynamical parameters.Results:The curvature of arterial loop [0.21(0.12) mm -1vs 0.13(0.07) mm -1, U=34.00, P<0.05], the angle between vascular loop and nerve [69.70(30.67)° vs 43.40(37.21)°, U=38.00, P<0.05] in the PTN group were significantly greater than those in the control group, and the location of compression was significantly closer to the root of nerve in the PTN group [PTN group: (4.23±1.29) mm vs control group: (5.54±1.85) mm, t=-2.26, P<0.05]. The average SS [15 952.48(5 365.56) Pa vs 12 501.97(6 355.26) Pa, U=53.00, P<0.05], ES [24 965.65(7 693.22) Pa vs 14 992.99(9 824.08) Pa, U=32.00, P<0.05] in the PTN group were significantly greater than those in the control group. The curvature of arterial loop was positively correlated with the SS ( r=0.931, P<0.05) and ES ( r=0.962, P<0.05), and the latter two ( r=0.787, P<0.05; r=0.853, P<0.05) were positively correlated with the local neural deformation. Conclusions:In patients with PTN, offending artery compresses the root of nerve by greater arterial curvature and angle between the arterial loop and nerve. These anatomical differences will cause significantly greater SS, ES and local neural deformation.