Keyes Joseph T, Simon Bruce R, Vande Geest Jonathan P
Graduate Interdisciplinary Program in Biomedical Engineering, The University of Arizona,Tucson, AZ 85721, USA.
J Biomech Eng. 2013 Jun;135(6):61008-11. doi: 10.1115/1.4024137.
Drug-eluting stents have a significant clinical advantage in late-stage restenosis due to the antiproliferative drug release. Understanding how drug transport occurs between coronary arterial locations can better help guide localized drug treatment options. Finite element models with properties from specific porcine coronary artery sections (left anterior descending (LAD), right (RCA); proximal, middle, distal regions) were created for stent deployment and drug delivery simulations. Stress, strain, pore fluid velocity, and drug concentrations were exported at different time points of simulation (0-180 days). Tests indicated that the highest stresses occurred in LAD sections. Higher-than-resting homeostatic levels of stress and strain existed at upwards of 3.0 mm away from the stented region, whereas concentration of species only reached 2.7 mm away from the stented region. Region-specific concentration showed 2.2 times higher concentrations in RCA artery sections at times corresponding to vascular remodeling (peak in the middle segment) compared to all other segments. These results suggest that wall transport can occur differently based on coronary artery location. Awareness of peak growth stimulators and where drug accumulation occurs in the vasculature can better help guide local drug delivery therapies.
药物洗脱支架由于抗增殖药物的释放,在晚期再狭窄方面具有显著的临床优势。了解药物在冠状动脉不同位置之间的转运方式,有助于更好地指导局部药物治疗方案。利用特定猪冠状动脉节段(左前降支(LAD)、右冠状动脉(RCA);近端、中段、远端区域)的特性创建有限元模型,用于支架植入和药物输送模拟。在模拟的不同时间点(0 - 180天)输出应力、应变、孔隙流体速度和药物浓度。测试表明,最高应力出现在LAD节段。在距支架区域向上3.0 mm以上的位置,应力和应变高于静息稳态水平,而物质浓度仅在距支架区域2.7 mm处达到峰值。在与血管重塑相对应的时间(中段峰值),RCA动脉节段的区域特异性浓度比所有其他节段高2.2倍。这些结果表明,基于冠状动脉位置的壁内转运可能会有所不同。了解峰值生长刺激因子以及药物在脉管系统中的积聚位置,有助于更好地指导局部药物输送治疗。