Atherosclerosis is a disease in blood vessels that often results in plaque formation and lumen narrowing. It is an inflammatory response of the tissue caused by disruptions in the vessel wall nourishment. Blood vessels are nourished by nutrients originating from the blood of the lumen. In medium-sized and larger vessels, nutrients are additionally provided from outside through a network of capillaries called vasa vasorum. It has recently been hypothesized (Haverich in Circulation 135:205–207, 2017) that the root of atherosclerotic diseases is the malfunction of the vasa vasorum. This, so-called outside-in theory, is supported by a recently developed numerical model (Soleimani et al. in Arch Comput Methods Eng 28:4263–4282, 2021) accounting for the inflammation initiation in the adventitial layer of the blood vessel. Building on the previous findings, this work proposes an extended material model for atherosclerosis formation that is based on the outside-in theory. Beside the description of growth kinematics and nutrient diffusion, the roles of monocytes, macrophages, foam cells, smooth muscle cells and collagen are accounted for in a nonlinear continuum mechanics framework. Cells are activated due to a lack of vessel wall nourishment and proliferate, migrate, differentiate and synthesize collagen, leading to the formation of a plaque. Numerical studies show that the onset of atherosclerosis can qualitatively be reproduced and back the new theory.

动脉粥样硬化是一种血管疾病，通常会导致斑块形成和管腔变窄。它是由血管壁营养破坏引起的组织炎症反应。血管由来自管腔血液的营养物质滋养。在中型和大型血管中，营养物质还通过称为滋养管的毛细血管网络从外部提供。最近有人假设（Haverich in Circulation 135:205–207, 2017）动脉粥样硬化疾病的根源是血管滋养管的功能障碍。这种所谓的由外向内理论得到了最近开发的数值模型的支持（Soleimani 等人，Arch ComputMethods Eng 28:4263–4282, 2021），该模型解释了血管外膜层炎症的起始。基于之前的发现，这项工作提出了一种基于由外向内理论的动脉粥样硬化形成的扩展材料模型。除了生长动力学和营养扩散的描述之外，单核细胞、巨噬细胞、泡沫细胞、平滑肌细胞和胶原蛋白的作用也在非线性连续介质力学框架中得到解释。细胞因缺乏血管壁营养而被激活并增殖、迁移、分化和合成胶原蛋白，导致斑块的形成。数值研究表明，动脉粥样硬化的发生可以定性地再现并支持新理论。