Computational Chemo-Fluidic Modeling of Thrombotic Occlusion in Aneurysms due to Flow Diverting Stents

Intracranial Aneurysms (IA) pose a significant risk of rupture, leading to subarachnoid hemorrhage with high fatality rates. Traditional treatments involve surgical clipping, endovascular coiling, and cerebral bypass surgery. In the last decade, Flow Diverting Stents (FDS) have emerged as a promising alternative. These stents are placed within the artery to reduce blood flow into the aneurysm, inducing flow stagnation and triggering thrombosis. The resulting thrombus restricts flow, preventing subsequent growth and rupture. Additionally, the stent acts as a scaffold for endothelium reconstruction. Despite these advancements, some IA cases still experience post-treatment rupture due to insufficient occlusion. To address this, we propose a more precise analysis using Computational Fluid Dynamics (CFD) modeling and simulation. Our approach models the stent as a porous membrane, allowing efficient computation. We use an inhomogeneous force model to account for tangential and normal component of the stent resistance force separately. By placing the membrane as an immersed boundary, we avoid complex meshing procedures. Our results demonstrate improved flow reduction inside the aneurysm and accurately capture the stent’s deflecting effect. For thrombosis modeling, we adopt a simplified approach based on platelet binding controlled by fibrin concentration, residence time, and shear stress. Our chemo-fluidic coupled simulations provide valuable insights for optimizing IA treatment.