Particle Adhesion on a Patient Specific Abdominal Aorta Aneurysm

Computational fluid particle dynamics techniques are employed to investigate particle adhesion on the vascular wall of a patient specific infrarenal abdominal aorta aneurysm (AAA). The particles are decorated with ligands that are assumed to interact with receptors expressed on the inflamed endothelium. In-house software is used for the generation of the computational grid from anonymous medical data, the calculation of the time-dependent flow field over a cardiac cycle, and the solution of the particle convection-diffusion equation. The effect of particle size and flow field on adhesion efficiency and location is investigated. It is found that for the 500nm particles high area average vascular deposition parameter (AAVDP) corresponds to areas of low Area average shear rate (AASR), whereas for the 50nm particles, AAVDP increases monotonically with AASR. In all cases, particles adhere predominately around the proximal and distal AAA necks and maximum deposition occurs at the areas of high flow residence time. Moreover, 50nm particles adhere diffusely on the vascular wall, whereas adhesion of 500nm particles is highly localized. For all particle diameters, however, the adhesion efficiency is almost negligible, as more than 99.9% of the released particles escape the AAA.