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 vE_locity (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 vE_locity (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 vE_locity, 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 vE_locity (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.

Key words: Anterosclerosis, Intracranial arterial diseases, Hemodynamics, Angioplasty, Stents

摘要：

目的: 探讨重度颅内动脉粥样硬化性狭窄（以下简称颅内动脉狭窄）非完全扩张管腔经皮血管内成形术和支架植入术（PTAS）的临床疗效和支架植入前后血流动力学变化。方法: 选择2018年2月至2023年2月在河北省石家庄市人民医院行非完全扩张管腔PTAS治疗的52例重度颅内动脉狭窄（狭窄率 > 70%）患者。记录术中植入支架后的残余狭窄率并采用改良Rankin量表（mRS）评估术前和术后6个月神经功能。采用MeshLab软件将血管三维影像学资料进行编辑，虚拟修复狭窄接近正常管腔，并获得支架植入前后狭窄动脉各段管壁和管腔内血流动力学参数。结果: 支架植入后的残余狭窄率为（15.34 ± 6.12）%，优于支架植入前[（84.60 ± 7.20）%；t= 98.672，P = 0.000]。术后6个月mRS评分（0.38 ± 0.21）分，低于术前[（1.21 ± 0.43）分；t= 24.124，P = 0.000]。与支架植入前狭窄动脉各段管壁血流动力学参数相比，支架植入后动脉近端正常段、狭窄段、远端正常段动态压力、总压力、剪切力、剪切率、单元雷诺数降低（均P = 0.000），狭窄分支根部动态压力（P = 0.000）、总压力（P = 0.000）、剪切力（P = 0.000）、剪切率（P = 0.008）、单元雷诺数（P = 0.000）亦降低。与支架植入前狭窄动脉各段管腔内血流动力学参数相比，支架植入后动脉近端正常段动态压力（P = 0.000）、总压力（P = 0.000）、血流速度（P = 0.000）、涡度（P = 0.005）、湍流动能（P = 0.000）、湍流强度（P = 0.000）、湍流耗散率（P = 0.000）、湍流雷诺数（P = 0.000）降低，单元雷诺数升高（P = 0.000）；除外血流速度（P = 0.138），狭窄分支根部动态压力、总压力、涡度、湍流动能、湍流强度、湍流耗散率、湍流雷诺数值降低（均P = 0.000）；狭窄段动态压力、总压力、血流速度、涡度、湍流动能、湍流强度、湍流耗散率、湍流雷诺数、单元雷诺数降低（均P = 0.000）；远端正常段动态压力（P = 0.000）、总压力（P = 0.000）、血流速度（P = 0.001）、涡度（P = 0.000）、湍流动能（P = 0.000）、湍流强度（P = 0.000）、湍流耗散率（P = 0.000）、湍流雷诺数（P = 0.000）降低，单元雷诺数升高（P = 0.000）。虚拟修复狭窄后各段管壁和管腔内血流动力学参数接近支架植入后血流动力学参数。结论: 非完全扩张管腔PTAS治疗重度颅内动脉狭窄可以改善狭窄动脉各段管壁和管腔内血流动力学参数，降低紊乱血流对管壁的损害，降低完全扩张狭窄可能造成的斑块破碎脱落栓塞远端脑组织的风险。

关键词: 动脉粥样硬化, 颅内动脉疾病, 血流动力学, 血管成形术, 支架