Blood pressure-driven rupture of blood vessels

To develop better diagnosis and treatment techniques of cardiovascular disease such as aneurysm, further understandings of the biomechanical mechanisms and failure behaviors of blood vessels is urgent. Importantly, blood pressure, residual stress, loads from surrounding tissues, and fluid-structure interactions greatly influence the spatiotemporal evolution of deformation and damage of blood vessels. However, directly incorporating these effects into a fluid-structure interaction mechanism analysis of blood vessels remains challenging. Here, we proposed a novel virtual bar model for surrounding tissues and correlated residual stress and loads from the surrounding tissues with perivascular pressures of blood vessels based on a strategy of pressure decomposition. Meanwhile, we developed a pristine meshfree framework incorporating both the Fung-type hyperelasticity and the Casson's non-Newtonian fluid model for modeling the deformation and rupture of blood vessels. An essential physical phenomenon, blood pressure-induced spontaneous ruptures of blood vessels, are successfully captured using our method. It should be highlighted that the effects of material constitutive model, loads from surrounding tissues, the off-axis distance of aneurysm and outlet resistance can be systematically characterized using the proposed model. Another valuable finding is that surrounding tissues have significant effects on the deformation and damage behaviors of blood vessel, however, it was ignored in most of biomechanics simulations. Our work will provide a landmark computational framework for studying surrounding tissues and a potential numerical implementation for fluid-driven failure analysis in biological tissues.