Numerical Simulation in Aortic Arch Aneurysm

Abstract

The aorta, acting as the main conduit through which cardiac output is delivered to the systemic arterial bed, is continuously exposed to high pulsatile pressure and shear stress, making it prone to mechanical injury. It is also more prone to rupture than other vessels, particularly with the development of aneurysmal dilation. Fifty percent of patients who experience a rupture of a aortic aneurysm die before reaching the hospital (Bengtsson & Bergqvist, 1993). The incidence increases with age and has been reported as 6 per 100,000 person-years (Knowles & Kneeshaw, 2004). Aneurysmal degeneration that occurs in the aortic arch is termed a aortic arch aneurysm. Patients who have aortic arch aneurysm have multiple aortic lesions or aneurysmal disease which involves segment of aorta (Crawford et al., 1984). Aortic arch aneurysms represent only 10% of aneurysms of the thoracic aorta and it has higher risk of rupture than other aneurysm (Knowles & Kneeshaw, 2004). Blood flow through the aorta is one of the most complex flow situations found in the cardiovascular system. Blood flow is pulsatile and pressure inside aortic aneurysm is nonuniform. The dynamics interaction between blood flow and wall may influence the wall stress. Computer modeling has made impressive progress in scientific, engineering, biological and medical applications in recent years and it offers the prospect of providing both a better insight into a range of biomechanical problems and improved tools for the design of medical devices and the diagnosis of pathologies. Computational methods such as mathematical modeling methods (Rideout, 1991; Rupnic & Runvovc, 2002; Abdolrazaghi et al., 2008), computational fluid dynamics methods, (Botnar et al., 2000; Shahcheraghi et al., 2002; Morris et al., 2005; Tokuda et al. 2008) loosely coupled methods (Di Mrrtino et al., 2001; Gao et al., 2006abc) have been used to simulate the biomechanical problems in arotic arch and aortic arch aneurysm. The aim of this chapter is to describe the numerical simulation and computer modeling work in aortic arch aneurysm.