Hemodynamic investigation of incomplete stent angioplasty with percutaneous transluminal angioplasty and stenting for severe intracranial atherosclerotic stenosis

Abstract

Objective To explore the clinical efficacy and changes in hemodynamic parameters before and after incomplete stent angioplasty with percutaneous transluminal angioplasty and stenting (PTAS) for severe intracranial atherosclerotic stenosis. Methods A total of 52 patients with severe intracranial artery stenosis (> 70%) who underwent incomplete stent angioplasty with PTAS at Shijiazhuang People's Hospital in Hebei from February 2018 to February 2023 were selected. The residual stenosis rate after implantation of stent was evaluated, and neurological function was evaluated before and 6 months after surgery by modified Rankin Scale (mRS). The MeshLab software was used to analyze three⁃dimensional imaging data of arterial vessels, perform virtual repair of arterial stenosis approaching normal vessel diameter, and obtain hemodynamic parameters of each segment of the arterial wall and lumen before and after implantation of stent. Results The residual stenosis rate after stent implantation was (15.34 ± 6.12)%, which was better than the stenosis rate before stent implantation [(84.60 ± 7.20)%; t = 98.672, P =0.000]. The mRS score 6 months after surgery was (0.38 ± 0.21) points, which was lower than before surgery [(1.21 ± 0.43) points; t = 24.124, P = 0.000]. Compared with the hemodynamic parameters of each segment of the arterial wall before stent implantation, the dynamic pressure, total pressure, shear stress,shear rate, and cell Reynolds number of the proximal normal segment, stenotic and distal normal segment of the artery decreased after stent implantation (P = 0.000, for all), also the dynamic pressure (P = 0.000), total pressure (P = 0.000), shear stress (P = 0.000), shear rate (P = 0.008), and cell Reynolds number (P = 0.000) of the narrowed branch root decreased. Compared with the hemodynamic parameters related to the lumen of each segment of the artery before stent implantation, the dynamic pressure (P = 0.000), total pressure (P = 0.000), blood flow velocity (P = 0.000), vorticity (P = 0.005), turbulence kinetic energy (P = 0.000), turbulence intensity (P = 0.000), turbulence dissipation rate (P = 0.000), and turbulence Reynolds number (P = 0.000) of the proximal normal segment of the artery decreased after stent implantation, while the cell Reynolds number increased (P = 0.000). Excluding blood flow velocity (P = 0.138), the dynamic pressure, total pressure, vorticity, turbulence kinetic energy, turbulence intensity, turbulence dissipation rate, and turbulence Reynolds number of the root and segment of the artery decreased (P = 0.000, for all). The dynamic pressure, total pressure, blood flow velocity, vorticity, turbulence kinetic enery, turbulence intensity, turbulence dissipation rate, and turbulence Reynolds number of stenotic segment of the artery decreased (P = 0.000, for all). The dynamic pressure (P = 0.000), total pressure (P = 0.000), blood flow velocity (P = 0.001), vorticity (P = 0.000), turbulence kinetic energy (P = 0.000), turbulence intensity (P =0.000), turbulence dissipation rate (P = 0.000), and turbulence Reynolds number (P = 0.000) of the distal normal segment decreased, while the cell Reynolds number increased (P = 0.000). The hemodynamic parameters of the wall and lumen after virtual repair of artery stenosis were close to those after stent implantation. Conclusions The use of incomplete stent angioplasty with PTAS for severe intracranial atherosclerotic stenosis can significantly alleviate clinical symptoms, improve hemodynamic parameters in each segment of the stenosis, reduce the damage of turbulent blood flow to the arterial wall, and lower the risk of plaque fragmentation, detachment, and embolism of distal brain tissue caused by complete dilation of the stenosis.

Keywords

• anterosclerosis; intracranial arterial diseases; hemodynamics; angioplasty; stents