A simple model of intimal thickening-effects of hypertension

A vast amount of death in the world has been attributed to atherosclerosis. This disease causes plaque formation and finally lack of blood supply to an organ. The prominent aim of this study is proposing an accurate and simple model to investigate the process of arterial wall thickening. In order to investigate LDL (low density lipoprotein) accumulation in arterial wall which is considered the first stage of atherosclerosis, a four layer model for arterial wall consisting of endothelium, intima, IEL and media is presented. All layers are treated as homogenous porous media. The four-layer arterial wall model is the most powerful and reliable tool for modeling LDL transport within arterial wall for various clinical conditions. This model has been solved both numerically using finite volume method and analytically. Obtained accumulated LDL in the intima is used to calculate oxidized LDL flux. Finally, the presented model and correlation between oxidized LDL and intimal growth obtained from clinical data afford the growth model for arterial wall. Furthermore, effect of hypertension on filtration velocity and rate of wall thickening has been studied which is in consistent with experimental data. Our results show that the average rate of intima thickening of hypertensive patients with 120 mmHg and 160 mmHg transmural pressure are 5.87µm/year and 6.12 µm/year, respectively. And this rate for healthy subjects with 70mmHg transmural pressure has been calculated 4.5 µm/year.