Abstract TP224: Clotting Analysis Of Computational Model Of Direct Thrombosis In Cerebral Aneaurysms

Introduction: Many direct thrombosis models for cerebral aneurysms include complicated clotting mechanisms. For example there are models accounts for biochemical reactions and hemodynamics, using a level-set method to track the surface of the expanding clot and models with a coupled direct thrombosis CFD model that predicts thrombus stability and platelet composition. The presented model simplifies clotting in favor of being better able to meet computational time demands whilst retaining sufficient accuracy for use in clinical settings. Methodology: A pulsatile-flow direct thrombosis-model has been created in ANSYS® Fluent using a transient-solution implicit pressure-based solver, wherein two patient-derived cerebral aneurysm geometries are applied, and a porous model and Michaelis Menten formulation inclusive of fibrinogen, thrombin and fibrin are applied to model clotting. Clotting is regulated by the concentration of fibrin and flow shear rate. Solutions are computed for each patient-derived cerebral aneurysm geometry with and without the inclusion of a stent and clotting outcomes are evaluated. Results: Total occlusion occurs in both patient-derived cerebral aneurysm geometries with the inclusion of a stent. Without stents installed, one patient-derived cerebral aneurysm geometry that included a giant aneurysm occluded fully, while the other aneurysm geometry partially occluded. Conclusion: The clotting outcomes for the aneurysms resulting in full occlusion make sense given significant reduction of flow into the aneurysm and wall-shear stress along the aneurysm wall. The isolated interaction between thrombin and fibrinogen to produce fibrin shown that the model is reasonable in comparison to clot times measured for a previously published thrombin-fibrinogen in vitro experiment . Future work incorporates the results of an in-vitro particle image velocimetry validation experiment inclusive of clotting for adjustment of the presented model.