[Comparison of stent displacement and displacement force after endovascular aneurysm repair with cross-limb or parallel-limb stent].

This study aims to investigate whether displacement force on stents can accurately represents the displacement of the stent after endovascular aneurysm repair (EVAR) by comparing the measured stent displacement with the displacement forces calculated by computational fluid dynamics (CFD). And the effect of cross-limb and parallel-limb EVAR on stent displacements is further studied. Based on our objective, in this study, ten cross-limb EVAR patients and ten parallel-limb EVAR patients in West China Hospital of Sichuan University were enrolled. Patient-specific models were first reconstructed based on the computed tomography angiography images, then the stent displacements were measured, and the displacement forces acting on the stents were calculated by CFD. Finally, the cosα value of the angle between the displacement force and the displacement vector was used to analyze the matching degree between the displacement and the displacement force. The results showed that the displacement forces on cross-limb stents and parallel-limb stents were (2.67 ± 2.14) N and (1.36 ± 0.48) N, respectively. Displacements of stent gravity center, stent displacements relative to vessel, and vessel displacements of cross-limb and parallel-limb stents were (4.43 ± 2.81) mm and (6.39 ± 2.62) mm, (0.88 ± 0.67) mm and (1.11 ± 0.71) mm, (3.55 ± 2.88) mm and (5.28 ± 2.52) mm, respectively. The mean cosα for cross-limb and parallel-limb stents were 0.02 ± 0.66 and - 0.10 ± 0.73, respectively. This study indicates that the displacement force on the stent can't accurately represent the displacement of the stent after EVAR. In addition, the cross-limb EVAR is probably safer and more stable than the parallel-limb EVAR.