The concept of aortic replacement based on computational fluid dynamic analysis: patient-directed aortic replacement

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Computational Fluid Dynamics

Background:

• Aortic replacement decisions typically rely on aortic diameter, excluding dissection or connective tissue diseases.
• Surgeon preference and patient factors influence the choice of aortic-to-prosthetic anastomotic positions.
• High stress on residual aortic tissue post-replacement can lead to aneurysm formation or dilatation.

Purpose of the Study:

• To define optimal operative interventions for aortic replacement using computational fluid dynamic (CFD) evaluation.
• To assess the impact of different aortic replacement strategies on stress distribution in residual aortic tissue.

Main Methods:

• A CFD analysis was performed on a simplified model of the ascending aorta, aortic arch, and descending aorta.
• Wall shear stress was evaluated in three dimensions for standard aortic replacement procedures: ascending, arch, and proximal descending aortic replacement.

Main Results:

• Hermiarch replacement demonstrated superior results, reducing tissue stress by up to tenfold compared to isolated ascending aortic replacement.
• Aortic arch replacement with island implantation of supra-aortic vessels potentially increases residual aortic stress tenfold.
• Aortic arch replacement with individual supra-aortic vessel implantation can cause high stress on native vessels if insufficient tissue is resected.

Conclusions:

• Patient-specific, 3D anatomical, and physiological CFD evaluations hold significant potential for optimizing aortic replacement surgical strategies.
• CFD analysis may guide future aortic replacement interventions, even in cases involving normal-diameter aortas.