Stagger-folding leaflet design for improved durability in transcatheter heart valves

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Materials Science

Background:

• Transcatheter valve replacement is standard for severe aortic stenosis in high-risk patients.
• Mechanical stress during crimping can damage transcatheter heart valve (THV) leaflets, leading to premature degeneration.
• Existing THV designs are susceptible to leaflet damage from crimping forces.

Purpose of the Study:

• To design and evaluate a novel stagger-folding transcatheter heart valve (THV) to minimize leaflet damage during the crimping process.
• To optimize the spatial distribution of THV leaflets using axial stagger-folding to reduce stress concentrations.
• To enhance the long-term durability of THV leaflets through improved folding mechanics.

Main Methods:

• Development of a novel stagger-folding mechanism for THV leaflets.
• Utilizing numerical simulations and multi-objective optimization to determine optimal axial stagger-folding displacements.
• Designing a stagger-folding valve stent based on optimized parameters.
• Comparative analysis of damage volume and stress distribution between stagger-folding and conventional normal-folding valves.

Main Results:

• The novel stagger-folding THV design effectively mitigated inter-leaflet compression during crimping.
• Numerical simulations showed a significant reduction in leaflet damage volume by 23.64% compared to conventional folding.
• The stagger-folding design substantially reduced stress concentrations associated with the valve crimping process.
• Optimized axial displacements were identified for the stagger-folding leaflets.

Conclusions:

• The novel stagger-folding THV design shows significant potential to reduce crimping-induced leaflet stress.
• This approach may enhance the durability and extend the service life of transcatheter heart valves.
• The findings provide valuable technical insights for the next generation of THV development.