Virtual Therapy Planning of Aortic Valve Replacement for Preventing Patient-Prosthesis Mismatch

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Computational Fluid Dynamics

Background:

• Patient-prosthesis mismatch (PPM) is linked to increased morbidity and mortality post-SAVR.
• Prosthesis size and patient activity levels are critical factors influencing SAVR outcomes.
• Computational fluid dynamics (CFD) can model these influences.

Purpose of the Study:

• To investigate the impact of prosthetic valve size on pressure gradients.
• To assess the effect of simulated physical activity on aortic valve hemodynamics post-SAVR.
• To explore the potential of virtual therapy planning for optimizing SAVR outcomes.

Main Methods:

• Virtual SAVR performed on 10 patients with aortic valve stenosis.
• Utilized 4D Flow imaging for stroke volume and flow direction.
• Simulated a 25% increase in stroke volume to represent physical activity.
• Calculated pressure gradients and blood flow profiles for three valve sizes at rest and stress.

Main Results:

• Larger valves resulted in significantly lower, though not normalized, aortic valve gradients.
• Simulated physical activity increased pressure gradients across all valve sizes.
• Blood flow profiles did not normalize post-SAVR and were unaffected by physical activity.
• Gradients indicated potential for moderate to severe stenosis under simulated activity.

Conclusions:

• Prosthesis size and simulated physical activity significantly influence aortic valve gradients.
• Current SAVR practices may not fully normalize hemodynamics.
• Patient-specific virtual therapy planning holds promise for improving SAVR outcomes.