Numerical modeling of permeability-sensitive flow and mass transport in a heterogeneous porous medium with application to aortic dissection

Aortic dissection is a life-threatening vascular disease in which false lumen thrombosis critically influences long-term prognosis. However, the effects of thrombus permeability heterogeneity on intraluminal transport remain poorly understood. In this study, a patient-specific aortic dissection model reconstructed from medical imaging data was used to investigate hemodynamics and mass transport under different thrombus occupancy conditions. Three representative configurations with low, moderate, and high thrombus occupancy were analyzed using a unified Darcy–Brinkman–Stokes (DBS) framework coupled with the finite volume method. Hemodynamic parameters, including velocity, pressure, wall shear stress, and platelet transport, were quantitatively evaluated. The results demonstrate that thrombus permeability heterogeneity significantly alters flow redistribution and transport behavior. Across the 32 patient-specific models, thrombus-induced porous resistance resulted in an average pressure elevation of approximately 500 Pa, indicating a significant contribution of permeability effects to false lumen hemodynamics (p < 0.005). Notably, at approximately 50% thrombus occupancy, the system exhibited heightened sensitivity to small porosity variations, resulting in substantial increases in blind-end pressure and intensified momentum exchange near the entry tear. This phenomenon was not observed under low or high thrombus occupancy conditions. Compared with conventional Navier–Stokes-based models, the DBS framework more effectively captured permeability-dependent transport dynamics. These findings indicate that thrombus permeability heterogeneity, rather than thrombus volume alone, is a critical determinant of nonlinear hemodynamic behavior in aortic dissection. The proposed framework bridges imaging-derived features and biomechanical properties, providing a basis for patient-specific prognostic assessment.