HEMODYNAMIC ALTERATIONS IN THORACIC AORTIC ANEURYSM: INSIGHTS FROM PATIENT-SPECIFIC COMPUTATIONAL SIMULATIONS WITH ANATOMICAL CONTROLS

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The pathological progression of thoracic aortic aneurysm (TAA) is strongly coupled with hemodynamic abnormalities, which are difficult to quantify using traditional medical imaging. To address this, this study proposes a patient-specific modeling-simulation-decision analysis framework based on multimodal image fusion. A three-dimensional geometric model of the TAA was reconstructed from the patient CTA data, and a corresponding healthy thoracic aortic model was generated as an internal control using a geometric repair algorithm. Computational fluid dynamics (CFD) was then employed to systematically compare their hemodynamic characteristics over the entire cardiac cycle. The results revealed that, compared to the normal vessel, the aneurysmal region exhibited significantly lower flow velocity ([Formula: see text] [Formula: see text]m/s), with a disordered flow field characterized by multiple vortex structures. Furthermore, this region demonstrated an abnormal biomechanical environment, including low time-averaged wall shear stress (TAWSS[Formula: see text]0.5 Pa) and high relative residence time (RRT[Formula: see text]12). These parametric features showed a significant positive correlation with endothelial dysfunction and thrombogenic risk. Additionally, at peak systolic ejection, wall pressure in the aneurysm reached its maximum, which was 1.6% higher than in the normal vessel and exhibited a phase-lag phenomenon, suggesting an elevated rupture risk. By establishing a systematic comparative framework between TAA and normal thoracic aortas, this study provides an important theoretical basis and an analytical tool for elucidating the underlying hemodynamic mechanisms and assisting in clinical risk assessment and treatment strategy formulation.

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