The effect of plaque eccentricity on blood hemodynamics and drug release in a stented artery

Abstract

Atherosclerosis in the coronary arteries is one of the leading causes of death in the world. Percutaneous coronary interventions (PCI) associated with the implantation of drug eluting stents (DES) is one of the most common forms of revascularization in patients with atherosclerotic coronary artery disease. The use of DES is considered as an effective tool to reduce restenosis after PCI. However despite all the progress made in DES procedures, the rate of restenosis remains relatively high. Mathematical modeling and numerical simulation are believed to play an essential role in identifying zones with a higher risk of in-stent restenosis. In this work the local delivery of a therapeutic agent, from a stent implanted in a coronary artery, is mathematically modeled and numerically simulated. The mathematical model includes the diffusion of the dissolved drug in the biodegradable polymeric coating of the stent, the diffusion and convection of the drug with reversible binding in the viscoelastic arterial wall with plaques of different morphology and the local hemodynamics. The study is an attempt to detect zones with a higher risk of in-stent restenosis and their relation to plaque eccentricity. The location of zones with highest risk of thrombosis and plaque rupture is also addressed. The results are in agreement with claims presented in clinical papers.

Keywords: Drug distribution; Eccentricity; In-stent restenosis; Numerical simulation; Wall shear stress.