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.

在过去的几十年中，旨在提高我们目前对生化过程的理解和预测疾病进展的模型越来越多地被使用。最近，我们提出了一种用于腹主动脉瘤 (AAA) 的动脉壁生长和重塑的有限元实施方案。该研究侧重于主动脉壁内的变化，不包括 AAA 演变过程中腔内血栓 (ILT) 的复杂作用。因此，在这项工作中，我们通过 ILT 的逐渐沉积及其对 AAA 生长的机械影响来扩展模型。尽管忽略了由于 ILT 的蛋白水解活性管腔层的存在而增加的生化活性，从而低估了潜在的破裂风险，我们表明，ILT 通过将血压负荷从轴向-径向平面重新定向到主要是径向方向，有助于减缓动脉瘤在轴向上的生长。这很可能会降低破裂的可能性。我们还表明，ILT 体积与体积囊的比率是 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可以更快地稳定且最大直径更小。此外，我们表明 ILT 的形成和相关的壁面应力降低会对壁成分的产生和厚度产生负面影响。尽管需要进一步的研究，包括 ILT 形成后壁的生化降解增加和基于血流动力学的 ILT 沉积，但目前的研究结果强调了 ILT 在 AAA 进展过程中所起的双重作用。