Computational studies of renal artery hemodynamics induced by breathing in patient-specific models of abdominal aortic aneurysms

Abdominal Aortic Aneurysm (AAA) is treated predominantly by endovascular aneurysm repair (EVAR), a minimally invasive insertion of a stent-graft (SG) into the aorta and, in some cases, fenestrated SGs in the renal arteries (RA). RA stenting can lead to occlusion. This study focuses on the effect of breathing-induced deformation on RA hemodynamics, a problem on which there are no studies to date. This motion is characterized by in vivo imaging. Changes in RA curvature and branching angle, associated with respiration, were measured in AAA patients. Numerical simulations are conducted to evaluate hemodynamic changes pre- and post-operatively. This research aims to assess if breathing-induced motion induces hemodynamic changes in the renal arteries that could result in thrombosis and occlusion. CFD simulations are conducted for two patients before and after EVAR, using a moving mesh, with motion prescribed by previous finite-element simulations of renal artery stenting and SG deformation. Hemodynamics in the renal arteries is assessed from Eulerian and Lagrangian metrics for thrombosis, with the goal of predicting EVAR complications.