Pulsatile blood flow in the thoracic aorta and aneurysm: a numerical simulation in CAD-built and patient-specific model

Two sets of geometric models were developed for the hemodynamic study of the thoracic aorta (with and without aneurysm): one patient-specific, built from computed tomography and another idealized, constructed in CAD software. The boundary conditions were established by a velocity pulse at the inlet of the thoracic aorta and a pressure pulse at the aorta outlets of an adult, normotensive, and resting subject. The CAD model for the healthy aorta closely approximates the patient-specific one; especially during the systolic peak with maximum percentage difference of 3.2 and 4.6% for, respectively, the pressure and velocity fields. The CAD-constructed aneurysm model, with 60% permanent diametric dilatation, is close to the minimum medical definition of an aortic aneurysm, which allowed the investigation of the minimal physiological changes that an aneurysm brings to the blood flow. Despite the striking difference in size in relation to the aneurysm of the patient-specific model, it was found that in most cases, the physical phenomena were similar in both models.