Vascular mechanics has been studied in depth since the early 1970s mainly following classical concepts from continuum mechanics. Yet, an important distinction of blood vessels, in contrast to typical engineering materials, is the continuous degradation and deposition of material in these living tissues. In this paper we examine mechanical consequences of such mass turnover. Motivated by Lyapunov’s stability theory, we introduce the new concepts of mechanobiological equilibrium and stability and demonstrate that blood vessels can maintain their structure and function under physiological conditions only if new material is deposited at a certain prestress and the vessels are both mechanically and mechanobiologically stable. Moreover, we introduce the concept of mechanobiological adaptivity as a third corner stone to understand vascular behavior on a continuum level. We demonstrate that adaptivity represents a key difference between the stability of mechanobiological and typical human-made systems. Based on these ideas, we suggest a change of paradigm that can be illustrated by considering a common arterial pathology. We suggest that aneurysms can be interpreted as mechanobiological instabilities and that predictions of their rupture risk should not only consider the maximal diameter or wall stress, but also the mechanobiological stability. A mathematical analysis of the impact of the different model parameters on the so-called mechanobiological stability margin, a single scalar used to characterize mechanobiological stability, reveals that this stability increases with the characteristic time constant of mass turnover, material stiffness, and capacity for stress-dependent changes in mass production. As each of these parameters may be modified by appropriate drugs, the theory developed in this paper may guide both prognosis and the development of new therapies for arterial pathologies such as aneurysms.

自 1970 年代初以来，血管力学一直在深入研究，主要遵循连续介质力学的经典概念。然而，与典型的工程材料相比，血管的一个重要区别是材料在这些活组织中的持续降解和沉积。在本文中，我们研究了这种大规模周转的机械后果。受李雅普诺夫稳定性理论的启发，我们引入了机械生物学平衡和稳定性的新概念，并证明只有在一定的预应力下沉积新材料并且血管在机械和机械生物学上都稳定时，血管才能在生理条件下保持其结构和功能。而且，我们引入了机械生物学适应性的概念，作为在连续层面上理解血管行为的第三个基石。我们证明了适应性代表了机械生物学和典型人造系统的稳定性之间的关键区别。基于这些想法，我们建议改变范式，可以通过考虑常见的动脉病理来说明。我们建议动脉瘤可以被解释为机械生物学不稳定性，并且其破裂风险的预测不仅应考虑最大直径或壁应力，还应考虑机械生物学稳定性。不同模型参数对所谓机械生物稳定性裕度的影响的数学分析，用于表征机械生物稳定性的单个标量，表明这种稳定性随着质量周转、材料刚度和大规模生产中应力相关变化的能力的特征时间常数而增加。由于这些参数中的每一个都可以通过适当的药物进行修改，因此本文中开发的理论可以指导预后和动脉瘤等动脉病变新疗法的开发。