Numerical and in-vitro experimental assessment of the performance of a novel designed expanded-polytetrafluoroethylene stentless bi-leaflet valve for aortic valve replacement

Guangyu Zhu; Munirah Binte Ismail; Masakazu Nakao; Qi Yuan; Joon Hock Yeo

doi:10.1371/journal.pone.0210780

Numerical and in-vitro experimental assessment of the performance of a novel designed expanded-polytetrafluoroethylene stentless bi-leaflet valve for aortic valve replacement

PLoS One. 2019 Jan 30;14(1):e0210780. doi: 10.1371/journal.pone.0210780. eCollection 2019.

Authors

Guangyu Zhu^{1

2}, Munirah Binte Ismail², Masakazu Nakao³, Qi Yuan¹, Joon Hock Yeo²

Affiliations

¹ School of Energy and Power Engineering, Xi'an Jiaotong University, Xian, Shaanxi, China.
² School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, Singapore.
³ Cardiothoracic Surgery, KK Women's and Children's Hospital, Singapore, Singapore.

Abstract

The expanded polytetrafluoroethylene (ePTFE) heart valve can serve as a viable option for prosthetic aortic valve. In this study, an ePTFE bi-leaflet valve design for aortic valve replacement (AVR) is presented, and the performance of the proposed valve was assessed numerically and experimentally. The valve was designed using CAE software. The dynamic behavior of the newly designed bi-leaflet valve under time-varying physiological pressure loading was first investigated by using commercial finite element code. Then, in-vitro tests were performed to validate the simulation and to assess the hemodynamic performance of the proposed design. A tri-leaflet ePTFE valve was tested in-vitro under the same conditions as a reference. The maximum leaflet coaptation area of the bi-leaflet valve during diastole was 216.3 mm2. When fully closed, no leakage gap was observed and the free edges of the molded valve formed S-shaped lines. The maximum Von Mises stress during a full cardiac cycle was 4.20 MPa. The dynamic performance of the bi-leaflet valve was validated by the in-vitro test under physiological aortic pressure pulse. The effective orifice area (EOA), mean pressure gradient, regurgitant volume, leakage volume and energy loss of the proposed valve were 3.14 cm2, 8.74 mmHg, 5.93 ml/beat, 1.55 ml/beat and 98.99 mJ, respectively. This study reports a novel bi-leaflet valve design for AVR. The performance of the proposed valve was numerically and experimentally assessed. Compared with the reference valve, the proposed design exhibited better structural and hemodynamic performances, which improved valve competency. Moreover, the performance of the bi-leaflet design is comparable to commercialized valves available on the market. The results of the present study provide a viable option for the future clinical applications.

Publication types

Research Support, Non-U.S. Gov't
Validation Study

MeSH terms

Aortic Valve*
Arterial Pressure
Computer Simulation
Computer-Aided Design
Coronary Circulation
Finite Element Analysis
Heart Valve Prosthesis*
Hemodynamics
Humans
Imaging, Three-Dimensional
In Vitro Techniques
Models, Cardiovascular
Polytetrafluoroethylene
Prosthesis Design*
Stress, Mechanical

Substances

Polytetrafluoroethylene

Grants and funding

This project is supported by the National Medical Research Council (NMRC) of the Republic of Singapore (NMRC/CIRG/1435/2015), China postdoctoral science foundation grant (2016M600781) and the Fundamental Research Funds for the Central Universities grant (XJJ2017032). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.