The investigation of systolic and diastolic leaflet kinematics of bioprostheses with a new in-vitro test method

Abstract

Objectives: We aimed to investigate leaflet kinematics of bioprostheses with a novel high-speed imaging method. Material and methods: High-speed-imaging (1000Hz) was used to evaluate leaflet kinematics of the Carpentier-Edwards Perimount Magna (PM) and Magna Ease (PME) aortic bioprostheses. Both prostheses (diameter 23 mm) were placed inside a model aorta under pulsatile flow conditions. Frequencies (F) and different stroke volumes (S) were simulated. Maximum aortic valve area (AVA), total ejection time (TET), rapid valve opening time (RVOT) and rapid valve closing time (RVCT) as well as opening (OS) and closing (CS) speeds were evaluated. Results: Both bioprostheses showed different results dependent on flow conditions. The test setup was capable of identifying small AVA-differences between both valves (235 vs 202 mm², F60/S60; 272 vs 207 mm²; F70/S80), as well as differences in OS and CS (2.36 vs 1.62 mm²/ms; 2.97 vs 2.44 mm²/ms, F80/S60). TET was comparable (638 vs 645 ms F60/S60; 341 vs 343 ms, F90/S60), while results for RVOT and RVCT were equal, and dependent on frequency and stroke volume. Conclusions: The novel evaluation method is sensitive to detect differences between valves, although differences were found to be small. PM has a larger visible AVA associated with higher opening and closing speeds in contrast to PME.

Key words:

• Aortic valve
• simulation
• flow channel
• fluid simulation
• bioprosthesis

Declaration of interest: All authors disclose any financial or personal relationship to organizations or people that could have inappropriately influenced our presented work. There was no funding or sponsorship related to this study.