B I O E N G I N E E R I N G Computational Modeling of Arterial Biomechanics

The arteries deliver blood from the heart to tissues, while the veins return blood to the heart. Although we sometimes think of arteries and veins as simple tubes, in reality they are much more complex: they curve and branch, which profoundly influences blood flow and biomechanical forces within the arterial wall. The artery wall is composed of several types of cells that interact with each other and can respond to biomechanical forces. Computational tools help us better understand the relationship between arterial geometric complexity, arterial biomechanics, and arterial wall biology. Diseases of the artery wall are the leading cause of death in Western society and are thus a major public health problem. Unfortunately, the specific causative link between biomechanical factors and arterial disease remains unknown,1 partly because of the significant complexity of the highly unsteady, three-dimensional biomechanical environment within the arteries. One way that computational technology is advancing the understanding of vascular disease is to let us simulate and quantify the biomechanical environment in otherwise inaccessible locations. For example, it is now possible to noninvasively image the 3D structure of a living patient’s arteries, then simulate the biomechanical forces within those arteries with comparable or better accuracy than available through direct, invasive measurement.2,3 Such simulations, when coupled with appropriately designed experiments, play an important role in helping understand the links between biomechanics and arterial disease. They might one day even help plan surgery and assess patient-specific risks. When severe arterial disease develops, surgery is usually the preferred option. We can now implant an arsenal of paraphernalia into the circulatory system, including artificial heart valves, synthetic bypass graft, stents designed to keep the artery propped open, and coils designed to block off aneurysms. The difficulty is that these devices do not always work as well as they could and can fail after several years, with serious consequences. There are many reasons for failure, but biomechanical factors are once again important. Here is another area where computing can play a key role: It can help us design better cardiovascular devices while shortening design cycle time. COMPUTATIONAL MODELING OF ARTERIAL BIOMECHANICS