Reducing descending aortic tortuosity improves thoracic endovascular aortic repair outcomes in type B aortic...

For patients with tortuous descending aortas undergoing thoracic endovascular aortic repair (TEVAR), reducing tortuosity may optimize stent-wall conformity and improve surgical outcomes, but its necessity remains unclear. This study aims to verify the necessity of reducing descending aortic tortuosity while sealing the tears during TEVAR for type B aortic dissection (TBAD) patients from a hemodynamic perspective. Radiological imaging data (pre- and post-TEVAR) of nine TBAD patients with tortuous descending aortas were collected, and subject-specific aortic geometries were reconstructed. Meanwhile, virtual TEVAR geometries with pre-TEVAR tortuosity were created as a control group for post-TEVAR. Computational fluid dynamics simulations were conducted and hemodynamic indicators were comparatively analyzed by statistics among three groups, including vorticity, displacement force, time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI) and relative residence time (RRT). Compared to pre-TEVAR, the hemodynamic indicators of the post-TEVAR group improved significantly (p < 0.050), while those in the virtual TEVAR group were not significant (p > 0.050). The post- and virtual TEVAR group exhibited improvements to pre-TEVAR in vorticity (36.44% vs. 27.10%), displacement force (14.51% vs. 4.77%), TAWSS (57.06% vs. 10.90%), OSI (27.24% vs. 6.03%) and RRT (48.58% vs. 16.74%), respectively. Additionally, the left subclavian artery perfusion in post-TEVAR increased by 58.73% compared with pre-TEVAR (p = 0.022), significantly more than the 22.68% increase (p = 0.175) in the virtual group. Reducing descending aortic tortuosity during TEVAR yields significant hemodynamic benefits. This may potentially enhance graft stability and promote long-term TEVAR efficacy.