Multiphase fluid-solid interaction analysis of stent-vessel-blood based on type B aortic dissection.

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Computational Fluid Dynamics

Background:

• Thoracic endovascular aortic repair (TEVAR) is a key treatment for Stanford type B aortic dissection (TB-AD).
• Existing finite element simulations for TB-AD often use simplified models, neglecting complex stent-vessel-blood interactions.
• Accurate simulation is crucial for optimizing TEVAR device design and treatment strategies.

Purpose of the Study:

• To develop and validate a patient-specific computational model for simulating TEVAR in TB-AD.
• To evaluate the biomechanical performance of different stent graft designs (5, 6, and 8-peak) in TB-AD treatment.
• To determine the optimal stent graft configuration for improving vascular function and reducing stress.

Main Methods:

• Patient-specific 3D vascular models of TB-AD were created using CT images and Boolean operations.
• Finite element analysis was used to simulate stent graft deployment (compression and release).
• A fluid-solid interaction module was employed for multiphase blood flow and vessel wall simulation.

Main Results:

• Stent graft deployment increased the cross-sectional area of dissected vessels by 60.0%-65.5%.
• Blood flow velocity in the true lumen decreased, while blood pressure increased in both lumens.
• Wall equivalent stress became more uniform and significantly reduced, with the eight-peak graft showing the best performance.

Conclusions:

• The eight-peak stent graft demonstrated superior biomechanical performance compared to 5 and 6-peak designs.
• This optimized stent graft design offers improved vascular morphology, blood flow dynamics, and reduced stress for TB-AD treatment.
• Patient-specific simulations are vital for advancing TEVAR device development and clinical application.