Non-Invasive Evaluation Of Fluid Dynamic Of Aortoiliac Atherosclerotic Disease: Impact Of Bifurcation Angle And Different Stent Configurations

Objectives: To non-invasively evaluate by computational fluid dynamic (CFD) analysis the physiology and rheology of aortoiliac bifurcation disease at different angles and different stent configurations. Material and Methods: For the analysis, we considered a physiologic model of abdominal aorta with an iliac bifurcation set at 30 degrees, 45 degrees and 70 degrees without stenosis. Subsequently, a bilateral ostial common iliac stenosis of 80% was considered for each type of bifurcation. For the stent simulation, we reconstructed Zilver vascular self-expanding (Zilver, Cook, Bloomington, MN) and Palmaz Genesis Peripheral (Gordis, Miami, FL) stents. Results: The physiologic model, across the different angles, static pressure, Reynolds number and stream function, were lower for the 30 degrees bifurcation angle with a gradient from 70 degrees to 30 degrees angles, whereas all the other parameters were inversely higher. After stenting, all the fluid parameters decreased homogenously independent of the stent type, maintaining a gradient in favour of 30 degrees compared to 45 degrees and 70 degrees angles. The absolute greater deviation from physiology was observed for low kissing when self-expandable stents were used across all angles; in particular, the wall shear stress was high at at 45 degrees angle. Conclusion: Bifurcation angle deeply impacts the physiology of aortoiliac bifurcations, which are used to predict the fluid dynamic profile after stenting. CFD, having the potential to be derived both from computed tomography scan or invasive angiography, appears to be an ideal tool to predict fluid dynamic profile before and after stenting in aortoiliac bifurcation.