Comparative analysis of patient-specific aortic dissections through computational fluid dynamics suggests increased likelihood of degeneration in partially thrombosed aorta

Aortic dissection is a life-threatening cardiovascular disease associated with high rates of morbidity and mortality, especially in medically under-served communities. It compromises the hemodynamics of the arteries that originate from the aorta, and its outcomes include visceral ischemia and aortic rupture in the acute phase and aneurysmatic degeneration in the chronic phase. Understanding patients’ blood flow patterns is pivotal for non-invasive evidence-based treatment as they greatly influence both the disease onset and its outcome. In this paper, we combine diagnostic imaging techniques and computational fluid dynamics to analyze the flow patterns of three aorta dissections (fully perfused, partially thrombosed, and fully thrombosed), and compare them to a healthy aorta. Besides flow kinematics, we focus on time averaged wall shear stress and oscillatory shear index that are recognized risk factors for aneurysm and rupture. Our analysis shows that partially thrombosed dissection is the most prone to false lumen degeneration. In all dissections, the arteries connected to the false lumen are generally poorly supplied with blood. Further, both true and false lumens present higher turbulence levels than the healthy aorta, and critical stagnation points. Mesh sensitivity and a thorough comparison against literature data together support the methodology robustness.