Find in Library

Background: The fenestrated stent technique has been developed for the treatment of aneurysms with branches. However, the hole size and type, which are the key factors for optimal treatment outcomes, are still controversial in clinical application. Therefore, a hemodynamics investigation in terms of the size and type of the hole was performed with the objective of providing evidence for optimization of this technique. Method: Six cases were modeled for comparison: cases 1 and 2 corresponded to suprarenal aortic aneurysm (SRAA) models with no stent and a multilayer stent (MS), respectively; cases 3–6 represented the SRAA models treated with fenestrated stent grafts (FSGs) including a small-sized hole (SSH, 3 ​mm), middle-sized hole (MSH, 6 ​mm), large-sized hole (LSH, 9 ​mm), and multiple holes (MH, which included the features of both the MS and stent graft, 6 ​mm), respectively. The total stent area in cases 4 and 6 was equal to the cross-section of the branch. Results: As opposed to cases 1 and 2, the pressure on the aneurysmal wall reduced more significantly with FSG intervention (cases 3–6), and the area of low wall shear stress (WSS) on the aneurysmal wall was unexpectedly large in case 5 owing to jet flow deflection. The branch flux increased with the increase of the hole size, and normal blood flow in the branch was only observed in case 5. Interestingly, the weakest jet flow was found in case 5. Conclusion: Our findings indicate that the diameter of the hole should be slightly larger than that of the branch to achieve better aneurysm isolation and preserve branch patency.