Numerical analysis of the impact of atherosclerotic plaque and different stent spacing on drug deposition

Objectives: To investigate the influence of atherosclerotic plaque and different drug-eluting stent (DES) spacing on drug deposition in the curved artery wall. Methods: Based on the computational fluid dynamics (CFD) method, the numerical investigation on distributions of drug concentration in the artery wall was carried out considering three different interstrut distances and five values of the plaque diffusion coefficients. The results were compared with those of the model without plaque. Results: Under the same stent spacing, drug deposition weakly increased with the increasing plaque diffusion coefficient. When the same diffusion coefficient value was taken, drug deposition presented steady growth with the expansion of stent spacing. When the stent spacing was of 1-strut length or the diffusion coefficient of plaque was much smaller than the diffusion coefficient of tissue (an order of magnitude or more), the drug deposition would be evidently reduced. Conclusions: In a curved artery, the stent spacing is still an important factor in drug deposition. The diffusion coefficients of plaque have little influence on the average drug concentration, but they show a relatively obvious effect on drug distributions.