Mechanical role of intraluminal thrombus in aneurysm growth: A computational study
Mechanical role of intraluminal thrombus in aneurysm growth: A computational study
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DOI：
10.1007/s10237-021-01478-w
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发表时间：
2021-06-20
影响因子：
3.5
通讯作者：
Karsaj, Igor
中科院分区：
文献类型：
--
作者：
Horvat, Nino;Virag, Lana;Karsaj, Igor
在过去的几十年里，寻求改善我们目前对生化过程的理解并预测疾病进展的模型得到了越来越多的使用。最近，我们提出了一种用于腹主动脉瘤(AAAs)的动脉壁生长和重塑的有限元方法。这项研究侧重于主动脉壁内的变化，不包括管腔内血栓(ILT)在AAA演变过程中的复杂作用。因此，在这项工作中，我们用ILT的逐渐沉积及其对AAA生长的力学影响来扩展该模型。尽管我们忽略了由于ILT的蛋白水解性腔层的存在而增加的生化活性，从而低估了破裂的风险潜力，但我们发现ILT通过将血压负荷从轴向-径向重定向到主要的径向，有助于减缓动脉瘤在轴向的生长。这很可能降低了破裂的可能性。ILT体积与体积囊的比值是AAA稳定的一个重要因素，与部分血栓形成的动脉瘤相比，完全血栓形成的动脉瘤稳定得更快，最大直径更小。此外，我们还发现，ILT的形成和相关壁应力的降低对壁组分的产量和厚度产生了负面影响。尽管还需要进一步的研究，包括ILT形成后壁的生化降解增加以及基于血流动力学的ILT沉积，但目前的发现强调了ILT在AAA进展中所起的双重作用。
Models that seek to improve our current understanding of biochemical processes and predict disease progression have been increasingly in use over the last decades. Recently, we proposed a finite element implementation of arterial wall growth and remodeling with application to abdominal aortic aneurysms (AAAs). The study focused on changes within the aortic wall and did not include the complex role of intraluminal thrombus (ILT) during the AAA evolution. Thus, in this work, we extend the model with a gradual deposition of ILT and its mechanical influence on AAA growth. Despite neglecting the increased biochemical activity due to the presence of a proteolytically active luminal layer of ILT, and thus underestimating rupture risk potential, we show that ILT helps to slow down the growth of the aneurysm in the axial direction by redirecting blood pressure loading from the axial-radial plane to predominately radial direction. This very likely lowers rupture potential. We also show that the ratio of ILT volume to volume sac is an important factor in AAA stabilization and that fully thrombosed aneurysms could stabilize quicker and at smaller maximum diameters compared to partially thrombosed ones. Furthermore, we show that ILT formation and the associated mural stress decrease negatively impact the wall constituent production and thickness. Although further studies that include increased biochemical degradation of the wall after the formation of ILT and ILT deposition based on hemodynamics are needed, the present findings highlight the dual role an ILT plays during AAA progression.