Insights on pulsatile flow in the human aorta following sudden deceleration and impact

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Motivated by the study of blood flow following an automotive accident and the mechanisms leading to blunt traumatic aortic rupture, this research program examines the pulsatile flow of an incompressible fluid in the human aorta subject to a sudden body deceleration and an impact force. Blunt traumatic aortic rupture is defined as a transverse tear or rupture of the aortic wall. It is the second cause of death, after head injury, from automotive accidents or pedestrian impacts. It accounts for 5-16% of cases and in North America and is responsible for 7000 to 8000 casualties per year (21 persons / day). It is attributed to the action of violent inertia forces applied directly or indirectly to the chest at the moment of an impact or high-speed deceleration. Blunt traumatic aortic rupture process is likely to result from both anatomic and mechanical factors and has been shown to be multi-factorial. Understanding the mechanisms leading to blunt traumatic aortic rupture is a crucial issue; it is a life-threatening event and most patients (80% to 90%) will die immediately or will not survive the journey to the hospital, thus, only 10% to 20% survive for medical treatment. Furthermore, current safety and crash protection systems do not allow, unfortunately, a significant reduction in blunt traumatic aortic rupture. Although quite frequent, the mechanisms leading to blunt traumatic aortic rupture are still not clearly identified. The fundamental questions this research program is trying to answer are: 1) how the fluid flow in a curved pipe (rigid or elastic) or human aorta reacts to sudden deceleration and an impact force; 2) what are the flow mechanisms involved in dissipating the energy resulting from this impact or how the flow reorganize itself to return to its pre-impact equilibrium configuration. This research program includes numerical and experimental investigations. Answering these fundamental questions will contribute to a better understanding of blunt traumatic aortic rupture and help automotive industry to optimize new safety and crash protection systems.