Related Experiment Video
Updated: May 1, 2026
Upper-extremity Approach for Secondary Access in Transfemoral Transcatheter Aortic Valve Implantation
Published on: August 8, 2025
An in vitro evaluation of the impact of eccentric deployment on transcatheter aortic valve hemodynamics
Paul S Gunning1, Neelakantan Saikrishnan, Laoise M McNamara
1Biomechanics Research Centre, Department of Biomedical Engineering, National University of Ireland Galway, Galway, Ireland.
Insights
Eccentric deployment of Transcatheter Aortic Valve Replacement (TAVR) stents causes turbulent blood flow and may increase blood cell damage. This occurs due to altered flow characteristics not detected by standard hemodynamic evaluation alone.
Area of Science:
- Cardiovascular Research
- Biomedical Engineering
- Fluid Dynamics
Background:
- Aortic stenosis involves calcium deposits on native valves, potentially causing non-concentric Transcatheter Aortic Valve Replacement (TAVR) stent expansion.
- Eccentric TAVR deployment may impact blood flow dynamics and cellular integrity.
Purpose of the Study:
- To investigate if eccentric TAVR deployment leads to turbulent blood flow and blood cell damage.
- To compare hemodynamic parameters and downstream flow characteristics between circular and eccentric TAVR deployments.
Main Methods:
- Utilized Particle Image Velocimetry (PIV) to analyze fluid velocity fields.
- Quantified shear stress and turbulent kinetic energy downstream of TAVRs in circular and eccentric configurations.
- Simulated TAVR deployment in representative circular and eccentric orifices.
Main Results:
- Eccentric TAVR deployment resulted in asymmetric systolic jet formation.
- Increased shear stresses (119 N/m² vs. 97 N/m²) and turbulence intensity (230 N/m² vs. 180 N/m²) were observed downstream of eccentrically deployed TAVRs.
- Effective orifice area and mean transvalvular pressure gradient showed minimal differences between circular and eccentric deployments.
Conclusions:
- Eccentric TAVR deployment alters blood flow dynamics, creating turbulence and elevated shear stress.
- These altered flow characteristics may increase the hemolytic potential of TAVR valves.
- Hemodynamic evaluation alone may not fully capture the risks associated with eccentric TAVR deployment.
Abstract:
Patients with aortic stenosis present with calcium deposits on the native aortic valve, which can result in non-concentric expansion of Transcatheter Aortic Valve Replacement (TAVR) stents. The objective of this study is to evaluate whether eccentric deployment of TAVRs lead to turbulent blood flow and blood cell damage. Particle Image Velocimetry was used to quantitatively characterize fluid velocity fields, shear stress and turbulent kinetic energy downstream of TAVRs deployed in circular and eccentric orifices representative of deployed TAVRs in vivo. Effective orifice area (EOA) and mean transvalvular pressure gradient (TVG) values did not differ substantially in circular and eccentric deployed valves, with only a minor decrease in EOA observed in the eccentric valve (2.0 cm(2) for circular, 1.9 cm(2) for eccentric). Eccentric deployed TAVR lead to asymmetric systolic jet formation, with increased shear stresses (circular = 97 N/m(2) vs. eccentric = 119 N/m(2)) and regions of turbulence intensity (circular = 180 N/m(2) vs. eccentric = 230 N/m(2)) downstream that was not present in the circular deployed TAVR. The results of this study indicate that eccentric deployment of TAVRs can lead to altered flow characteristics and may potentially increase the hemolytic potential of the valve, which were not captured through hemodynamic evaluation alone.
