Optimal shape of prosthesis for tricuspid valve replacement

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Medical Device Design

Background:

• Developing optimal tricuspid valve prostheses is crucial for improving cardiac function.
• The shape of the tricuspid valve annulus influences cardiac performance.
• Current prostheses may not fully address the complex geometry of the native annulus.

Purpose of the Study:

• To determine the optimal flat ratio (long/short axis) of a metal ring prosthesis for the tricuspid valve annulus.
• To evaluate the impact of varying annulus shapes on cardiac performance.
• To compare the hemodynamics of non-circular prostheses with conventional circular designs.

Main Methods:

• Utilized an isolated autoperfusion model and an in vivo canine model.
• Assessed left ventricular stroke work and pulmonary trunk artery blood flow at different flat ratios.
• Performed right ventriculography to measure radial shortening.

Main Results:

• A flat ratio of 1.6 significantly increased left ventricular stroke work compared to other ratios (p < 0.05).
• Pulmonary trunk artery blood flow was significantly higher with a flat ratio of 1.6 (p < 0.05).
• Radial shortening of the right ventricle apex increased significantly with a flat ratio of 1.6 (49.2%) versus 1.0 (19.4%) (p < 0.05).

Conclusions:

• A flat ratio of 1.6 for tricuspid valve annulus prostheses yields superior hemodynamic results.
• This non-circular design offers more advantageous hemodynamics than traditional circular prostheses.
• The findings support the development of variable-ratio prostheses for improved tricuspid valve function.