Observation of hemodynamics in human descending aorta after V-shaped stent implantation

YANG Jin-you; WANG Yan; LIU Jing; YU Hang; HONG Yang

doi:10.3969/j.issn.1002-266X.2015.07.004

Abstract：Objective To observe the hemodynamic parameters of the descending aorta with expanded V-shaped stent implantation , and to investigate the relationships between the stent number and vascular restenosis in the distal stents . Methods The enhanced CT image of the descending aorta with the V-shaped stents implanted was input into the medical image processing software with Dicom format , and the three-dimensional reconstruction model of aortic and stent was recon-structed by reverse engineering methods .On the basis of setting the boundary condition and initial condition , the vascular wall shear stress , wall oscillation shear stress , stent cross section flow velocity vector and other related hemodynamic pa-rameters were obtained with the application of ANSYS simulation software after several times of iterative calculation .Re-sults From the near to the distant , the wall shear stress values on the different positions were 3.56 Pa, 3.26Pa and 3.26 Pa, and the average values of oscillating shear index were 0.002 140, 0.005 677 and 0.010 852, respectively.In the sys-tolic peak period (0.08 s), the blood flow velocities of the cross sections of three stents were larger with changeable direc -tions and had a great impact on the stent .While in the end-systolic and diastolic period , the flow velocity was slow down , but the flow velocity was still high in the contact point , and the eddy current was obvious in the diastolic phase .Conclu-sion With the stent increases , the wall shear stress value of the descending aorta decreases in the distal end but the wall oscillatory shear index value increases , meanwhile, the blood flow velocity vector of the stent cross section becomes more complex, and the risk of vascular restenosis increases .