In vitro four-dimensional flow magnetic resonance analysis of the effect of pericardial valve design on aortic flow

Abstract

We investigated the effect of the design of bioprosthetic pericardial valves on the downstream fluid flow pattern through four-dimensional flow magnetic resonance imaging (4D Flow). A dedicated in vitro test bench, including a paradigmatic aortic root phantom, was used to compare, under steady flow conditions, three commercially used pericardial bioprostheses (Trifecta^TM, Carpentier-Edwards PERIMOUNT Magna, Crown PRT®), selecting the two smallest and comparable valve sizes. In-house 4D Flow post-processing provided the downstream flow pattern of velocity, the velocity profile at vena contracta, its effective orifice area (EOA) and the corresponding hydraulic diameter (D_H). Trifecta reported the lowest peak of velocity for both the tested sizes, with vena contracta position being the most proximal to the free margin of leaflets. Conversely, in both Crown and Magna, jet flow continued to increase its downstream velocity, resulting in a farther position of vena contracta. EOA shape was trilobal for Magna, triangular for Crown and circular for Trifecta, the last one maximising EOA. The percentage of nominal luminal area effectively exploited by the flow was largely above 80% in Trifecta, below 75% in Crown and below 70% in Magna. Hence, the design of pericardial bioprostheses directly impacts on the downstream flow field pattern and its fluid dynamic performance.

Keywords:

• 4D Flow
• bioprosthetic valves
• haemodynamics
• in vitro analysis
• bioengineering

Acknowledgements

The authors thank Denis Tresova and Elvis Tresova for their valuable assistance in 4D Flow data acquisitions.

Disclosure statement

Giordano Tasca received lecture fees from Abbott Company. The rest of the Authors have nothing to declare.

Data availability statement

The data supporting the findings of the present study are available from the corresponding author upon reasonable request.

Additional information

Funding

This work has been supported by IRCCS Policlinico San Donato, a clinical research hospital partially funded by the Italian Ministry of Health.