An experimental evaluation of a concept to improve conventional aortic prostheses

Area of Science:

• Biomedical Engineering
• Cardiovascular Surgery
• Materials Science

Background:

• Conventional textile aortic prostheses exhibit lower compliance than native tissue, increasing cardiovascular risk and complications.
• Graft placement causes an acute drop in compliance, impacting patient outcomes.
• Graft-related complications are a significant concern in aortic aneurysm repair.

Purpose of the Study:

• To investigate a novel concept for improving the compliance of conventional aortic prostheses.
• To experimentally assess the effect of a custom-made spring casing on Dacron graft compliance.
• To evaluate the impact of the spring casing on pulse pressure and pulse wave velocity.

Main Methods:

• A custom-made spring casing was applied to a Dacron graft segment.
• Experiments were conducted in a five-element biventricular mock circulation loop under physiological conditions.
• Graft performance was characterized by measuring fluid pressures and flow to determine pulse pressure (PP) and pulse wave velocity (PWV).

Main Results:

• In a proximal graft setting, the spring casing reduced PP by 10-14% and slowed PWV by 22%.
• In a distal graft setting, the spring casing significantly reduced PWV by 60%, with a smaller impact on PP (2-10%).
• The custom-made spring casing demonstrated significant effects on hemodynamic parameters.

Conclusions:

• A novel spring casing applied externally to synthetic aortic grafts can reduce PP and slow PWV.
• This concept has the potential to improve long-term outcomes by restoring elastic recoil in stiff aortic prostheses.
• The findings suggest a promising solution for mitigating aortic prosthesis-related complications.