Study On The Influence Of Corolla Iliac Vein Stent On Flow Field Of Bifurcation

Iliac vein compression syndrome is a series of clinical symptoms with the level of the right common iliac artery across the left common iliac artery.Because of the right iliac artery in front of the left iliac vein,the posterior iliac crest is pushed forward,causing the left iliac vein to be compressed for a long time,ending with venous return disorders of the lower extremities and femoral vascular insufficiency.At present,the treatment of stenosis or occlusion of the iliac vein is mainly includes surgical or interventional.Surgery includes iliac vein incision,radial artery extraction,radial artery posterior surgery,venous bypass and other procedures,but these methods have the disadvantages of large trauma,many complications,and poor long-term efficacy.Interventional therapy mainly includes balloon dilatation and stenting.The balloon dilatation for the treatment of iliac vein stenosis or occlusion often causes stenosis or occlusion due to intimal tear and elastic retraction.Simple and minimally invasive,it has gradually replaced traditional open surgery.A novel nitinol iliac vein stent was used to simulate the flow field after iliac vein implantation with a hydrodynamic method.The blood flow of the iliac vein bifurcation was explored by the number of stent corollas and the height of the implantation.The influence law of kinetics provides an important reference for the prevention and treatment of sacral vein compression syndrome.Firstly,by studying the influence of number of corollas(no corolla,5 corollas and 15 corollas)on the average exit velocity and pressure difference between the inlet and outlet of the basin and the high and low wall shear stress areas,the influence of number of corollas on the contralateral blood flow was revealed.Secondly,by studying the effect of stent height(0,10 and 20 mm)on the average exit velocity of the basin segment,the pressure difference between the inlet and outlet and high and low wall shear stress regions,the stent implantation height was explored for the treatment of axillary stenosis or occlusion.Finally,rationality and correctness of the theoretical analysis were verified by in vitro experiments and control animal experiments(14,30,60 and 90 days),and provided a reference for reducing the impact of the stent on the contralateral blood flow and reducing the risk of thrombosis.Through the above studies,it is confirmed that the stent corolla not only plays a good role in the operation,but also reduces the influence on the contralateral blood flow and reduces the risk of thrombosis.It was found that the area of low wall shear stress in the iliac vein is not only related to the number of stent corollas and the height of the implant,but also directly related to the contact between the stent and the blood vessel.The hemodynamic study of the iliac vein implanted stent not only lays a theoretical foundation for the development of the new iliac vein stent,but also provides a scientific reference for clinical application.