摘要
动静脉内瘘(AVF)是血液透析患者首选的血管通路.AVF钙化是术后常见的并发症之一,其会引起AVF功能障碍、降低AVF的存活率、导致手术失败,然而关于AVF钙化的机制以及血流动力学的改变对AVF钙化的影响的研究并不充分.研究血流动力学参数与AVF钙化之间的关系,可为早期预测钙化位置提供依据.本文基于计算机断层扫描技术获得的患者AVF数据,用MIMICS 17软件重构了患者血管的三维几何模型,并对得到的三维几何模型的表面进行了光滑处理;用快速傅里叶变换对相应的多普勒超声图像数据进行处理,取前11阶重构得到的流速作为桡动脉进出口流速;根据以上基础,用计算流体动力学模拟软件ANSYS Fluent中基于不可压缩非牛顿流体的雷诺平均的Navier-Stokes方程求解血管内的流场.对数值模拟结果进行处理和计算,得到血管壁面剪切应力τW分布图、振荡剪切指数Ios、平均剪切应力τa和相对停留时间tRR.对以上指标与病人实际钙化区域进行对比和分析的结果表明:在Ios值较高且τa值较低的区域,血管壁更倾向于钙化,综合Ios和τa这2个指标可判断血管壁某区域是否倾向于发生钙化;tRR可以作为描述动脉粥样硬化问题的单一指标,但在预测钙化发生位置的问题中并没有表现出更强的相关性,仅可以辅助Ios和τa预测钙化出现的范围.
Arteriovenous fistulas(AVFs)are the primary vascular access for patients undergoing hemodialysis.AVF calcification is one of the most common postoperative complications,which can cause AVF dysfunction,reduce AVF survival rates,and lead to surgical failure.However,research on the mechanism of AVF calcification and the impact of hemodynamic factors contributing to it is not sufficient.Investigating the relationship between hemodynamic parameters and AVF calcification can provide a basis for early prediction of calcification sites.This study employs patient AVF data obtained through computed tomography to reconstruct a detailed three-dimensional geometric model of blood vessels.MIMICS 17 software was used to smooth the surface of the modeled geometry.Doppler ultrasound image data were analyzed using fast Fourier transform,reconstructing the flow velocity based on the first 11 orders to define the radial artery inlet and outlet flow velocities.On this basis,the flow field inside blood vessels was solved using the Navier-Stokes equations based on Reynolds averaged incompressible non-Newtonian fluids in the computational fluid dynamics simulation software ANSYS Fluent.The numerical simulation results were processed and calculated to obtain the distribution map of wall shear stressτW,oscillatory shear index Ios,time-averaged wall shear stressτa,and relative residence time tRR on the vascular walls.The comparison and analysis of these indicators with the actual calcified areas of patients showed that in areas with high Ios values and lowτa values,the vascular wall is more prone to calcification.By combining Ios andτa measurements,identifying certain areas of the vascular wall prone to calcification is possible.tRR can be used as a single indicator to describe atherosclerosis;however,it shows a weaker correlation for predicting the location of calcification.Instead,tRR primarily complements Ios andτa to predict the extent of calcification.
作者
袁德奎
宁慧慧
王喆
王耀宏
Yuan Dekui;Ning Huihui;Wang Zhe;Wang Yaohong(State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation,Tianjin University,Tianjin 300072,China;School of Mechanical Engineering,Tianjin University,Tianjin 300350,China;Department of Kidney Disease and Blood Purification,The Second Hospital of Tianjin Medical University,Tianjin 300211,China;Center for Applied Mathematics,Tianjin University,Tianjin 300350,China)
出处
《天津大学学报(自然科学与工程技术版)》
北大核心
2025年第10期1076-1082,共7页
Journal of Tianjin University:Science and Technology
基金
天津市教委科研计划项目(2022KJ254).
关键词
动静脉内瘘
血管钙化
壁面剪切应力
振荡剪切指数
平均剪切应力
相对停留时间
arteriovenous fistula
vascular calcification
wall shear stress
oscillatory shear index
time-averaged wall shear stress
relative residence time
