Objective To study the hemodynamic characteristics of autologous arteriovenous fistula(AVF)and provide a theoretical basis for reducing its stenosis rate.Methods Bidirectional fluid-structure interaction(FSI)simulations were conducted on a modified AVF model.Flow field and wall shear stress(WSS)distributions in the internal fistula at different periods and angles in a cardiac cycle were analyzed for retrograde flow(confluence)and anterograde flow(shunt)modes in models with varying anastomosis angles.Results Under confluence modes,the WSS＜1 Pa area in the 60° anastomosis angle model was the smallest(7.027 mm2),while the 45°,60°,and 90° models showed no significant differences in eddy current size and intensity.Under shunt modes,the 45° anastomosis angle model had the smallest WSS＜1 Pa area(9.079 mm2),but the 60° model exhibited the lowest eddy current intensity and distribution area.In addition,the difference in the WSS＜1 Pa area between the 60° and 45° models was only 2.661 mm2.Conclusions Under both confluence and shunt flow modes,establishing an AVF with 60° anastomosis angle is conducive to reducing the risk of vascular stenosis in arteriovenous fistula.

Objective To study the hemodynamic characteristics of autologous arteriovenous fistula(AVF)and provide a theoretical basis for reducing its stenosis rate.Methods Bidirectional fluid-structure interaction(FSI)simulations were conducted on a modified AVF model.Flow field and wall shear stress(WSS)distributions in the internal fistula at different periods and angles in a cardiac cycle were analyzed for retrograde flow(confluence)and anterograde flow(shunt)modes in models with varying anastomosis angles.Results Under confluence modes,the WSS＜1 Pa area in the 60° anastomosis angle model was the smallest(7.027 mm2),while the 45°,60°,and 90° models showed no significant differences in eddy current size and intensity.Under shunt modes,the 45° anastomosis angle model had the smallest WSS＜1 Pa area(9.079 mm2),but the 60° model exhibited the lowest eddy current intensity and distribution area.In addition,the difference in the WSS＜1 Pa area between the 60° and 45° models was only 2.661 mm2.Conclusions Under both confluence and shunt flow modes,establishing an AVF with 60° anastomosis angle is conducive to reducing the risk of vascular stenosis in arteriovenous fistula.