A new heterogenous porous model to simulate effects of intracranial aneurysm coiling for clinical risk prediction, validated using coil-resolved synchrotron scans.

We study intracranial aneurysms treated with endovascular coils deployed in the aneurysm dome to reduce flow, thereby allowing the aneurysm to heal. Standard model for the coils is a homogenous, isotropic porous medium. However, we have found that the distribution of coils produces a highly heterogeneous porosity field. Exploiting the observed pattern of larger porosity values near the wall and lower, more homogenous mass towards the aneurysmal core, a bi-linear model is proposed. This model is resolvable from information known a priori through standard treatment protocols: target porosity and aneurysm volume/shape. To validate this model and gain further insight into effects of the coil mass on intra-aneurysmal flow and treatment effectiveness, simulations of fully resolved coiled aneurysms are performed and compared against the novel model results. The data shows that the bi-linear model is a significant improvement over the standard model for prediction of hemodynamics. This model is being implemented in a large cohort study to predict coil treatment outcomes.