Is Multiple Overlapping Uncovered Stents Technique Suitable for Aortic Aneurysm Repair?

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Fluid Dynamics

Background:

• Complex aortic aneurysms pose significant treatment challenges.
• Endovascular techniques are increasingly utilized for aneurysm repair.
• Understanding intra-aneurysmal hemodynamics is crucial for treatment efficacy.

Purpose of the Study:

• To computationally assess the hemodynamic impact of flow-diverter devices in complex aortic aneurysms.
• To investigate the effectiveness of multiple overlapping uncovered stents (MOUS) in promoting aneurysm thrombosis.
• To evaluate the influence of MOUS on branch vessel patency.

Main Methods:

• Development of a computational fluid dynamic (CFD) model.
• Simulation of blood flow patterns within aortic aneurysms treated with MOUS.
• Analysis of hemodynamic parameters including time-averaged wall shear stress (TAWSS), relative residence time (RRT), and oscillatory shear index (OSI).

Main Results:

• MOUS placement significantly reduced intra-aneurysmal flow.
• Low TAWSS, high RRT, and high OSI regions were observed within the aneurysm sac, promoting thrombosis.
• Three to four MOUS stents created the most favorable hemodynamic environment for thrombus formation.
• Saccular aneurysms demonstrated better hemodynamic outcomes than fusiform aneurysms.
• Branch vessel flow remained patent, indicating preservation of side branches.

Conclusions:

• The use of three to four MOUS stents is a feasible endovascular solution for treating complex aortic aneurysms with side branches.
• This technique promotes aneurysm stabilization through favorable hemodynamic alterations.
• Saccular aneurysms are more amenable to treatment with MOUS compared to fusiform aneurysms.
• MOUS deployment effectively preserves branch vessel patency while stabilizing the aneurysm.