In-stent restenosis occurs in coronary arteries after implantation of drug-eluting stents with non-uniform restenosis thickness distribution in the artery cross section. Knowledge of the spatio-temporal drug uptake in the arterial wall is useful for investigating restenosis growth but may often be very expensive/difficult to acquire experimentally. In this study, local delivery of a hydrophobic drug from a drug-eluting stent implanted in a coronary artery is mathematically modelled to investigate the drug release and spatio-temporal drug distribution in the arterial wall. The model integrates drug diffusion in the coating and drug diffusion with reversible binding in the arterial wall. The model is solved by the finite volume method for both high and low drug loadings relative to its solubility in the stent coating with varied isotropic-anisotropic vascular drug diffusivities. Drug release profiles in the coating are observed to depend not only on the coating drug diffusivity but also on the properties of the surrounding arterial wall. Time dependencies of the spatially averaged free- and bound-drug levels in the arterial wall on the coating and vascular drug diffusivities are discussed. Anisotropic vascular drug diffusivities result in slightly different average drug levels in the arterial wall but with very different spatial distributions. Higher circumferential vascular diffusivity results in more uniform drug loading in the upper layers and is potentially beneficial in reducing in-stent restenosis. An analytical expression is derived which can be used to determine regions in the arterial with higher free-drug concentration than bound-drug concentration.
|Number of pages||12|
|Journal||Computer Methods in Biomechanics and Biomedical Engineering|
|State||Published - Feb 2014|
Bibliographical noteFunding Information:
Support is acknowledged from the National Institutes of Health NIBIB 5RO1EB005181 and the National Science Foundation (Grant no.0426328). The last author thanks David Mooney for hosting him at Harvard University while this paper was being written.
- anisotropic diffusivity
- arterial drug distribution
- drug-eluting stents
- mathematical modelling
ASJC Scopus subject areas
- Biomedical Engineering
- Human-Computer Interaction
- Computer Science Applications