Drug-eluting stent (DES) as the newly developed treatment for the cardiovascular disease has been the preferred treatment option for most of the patients with significant reduction of restenosis incidents. However, the follow-up complications such as late thrombosis after stent implantation limit the further widespread use of DES which has caused extensive attention from the researchers. Numerical method has been widely employed to predict the DES performance in human body during the past decades, contributing to the stent design optimization and a better understanding of drug release mechanisms in a cost-effective way compared to the experiments. Among the existing numerical investigations, different modelling methods of DES inside artery can be found to study the drug transport process, and adopting the proper models physically and mathematically plays a key role to obtain the results well fitting with the practical case. Therefore, in this review article, the existing numerical researches regarding DES mainly in the last two decades have been focused and summarized including the established modeling methods and the controlling parameters investigations related to drug release from DES. In addition, the common results obtained have been discussed collectively aiming to guide the following researches.
2
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Tortuosity in coronary artery has been found to be greatly related to the potential sites of stenosis in these last years. Many investigations have been carried out based on the tool of Computational Fluid Dynamics (CFD) mainly focusing on the influences of curved artery in blood flow. Within the limited investigations of coupling between stenosis and tortuosity, the stenosis has been considered to be located at the tortuous segment. However, with recent clinical studies, the case of stenosis occurred at non-tortuous segment before tortuosities has been confirmed which has not been paid enough attention yet. Therefore, the present study aims to investigate the disturbed streamlines and hemodynamics in curved and spiral artery considering symmetrical and asymmetrical stenosis upstream these tortuosities. Different stenosis severities, pulse rates and distances between stenosis and tortuosity as controlling parameters have been studied. The distribution of time averaged wall shear stress (TAWSS) and streamlines through tortuous segment have been displayed in order to determine the potential disease sites. Artery surface of TAWSS below critical value has been quantified as well to evaluate the risks of atherosclerosis. The results reveal that larger artery surface of TAWSS below critical value generally goes with smaller pulse rate, larger stenosis severity and distance between stenosis and tortuosity both for curved and spiral artery. However, exceptions were found in the cases of distance of 6 mm in curved artery with symmetrical stenosis and stenosis severity of 50% in spiral artery. Moreover, the spiral tortuosity tends to suppress the potential risks of atherosclerosis compared to curved tortuosity.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.