Progression from Initial Lesions to Type B Aortic Dissection: A Patient-Specific Study of Computational Fluid Dynamics Models with Follow-up Data.

Background and objective: The natural history of type B aortic intramural hematoma (IMH) is highly heterogeneous. A computational fluid dynamics (CFD) model can be utilized to calculate a range of data pertinent to flow dynamics, including flow rates, blood velocity, pressure, and wall shear stress. This study presents a series of CFD simulations that model the dynamic progression from type B aortic IMH to false lumen formation.

Methods: A 66-year-old male patient presenting with chest and back pain underwent aortic computed tomography angiography (CTA), and a 3D patient-specific model was constructed. To evaluate the hemodynamic environment, the velocity, pressure, time-averaged wall shear stress (TAWSS), and oscillatory shear index (OSI) were calculated.

Results: A modest quantity of slow flow and recirculation flow was observed in the vicinity of the ulcer-like protrusion (ULP). During the formation of the false lumen, low-velocity blood flow entered the false lumen and resulted in vortex flow. ULPs were located in the region with higher TAWSS, and some high OSIs were found on the ULPs.

Conclusion: This preliminary study suggests a potential association between the TAWSS or OSI and progression from type B aortic IMH to aortic dissection.