Lattice Boltzmann Simulations of Drug Delivery in Stented Brain Arteries

Cerebrovascular diseases such as brain aneurysms are a primary cause of adult disability and mortality. A possible treatment of aneurysms is the implantation of flow-diverting stents to stabilize the affected vessel. However, angioplasty procedures have adverse effects including in-stent restenosis. This risk can be reduced by using drug-coated stents that interrupt restenosis through local drug delivery, and knowledge of the spatio-temporal drug concentration in the blood vessel is a critical factor in improving stent design. The lattice Boltzmann method has been successfully applied to simulate blood flow in patient-specific models of brain arteries that are reconstructed from three-dimensional angiography images of the vasculature. In this contribution, we present an extension of this framework that uses virtual angioplasty to insert a drug-eluting stent into the segmented blood vessel. A lattice Boltzmann solver for the advection-diffusion equation is coupled to the fluid flow in order to study the diffusion of drug in the blood stream. We present results on the spatio-temporal distribution of drugs for different diffusion coefficients, stent-geometries, and coating patterns that can be used to optimize the design of vascular stents.