Experimental Study of Right Ventricular Hemodynamics After Tricuspid
Valve Replacement Therapies to Treat Tricuspid Regurgitation
Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore;
Department of Biomedical
Engineering, University of Michigan, Ann Arbor, MI 48109, USA; and
Department of Cardiology, National University Heart
Centre, Singapore, Singapore
(Received 14 February 2017; accepted 21 August 2017; published online 29 August 2017)
Associate Editor Ulrich Steinseifer oversaw the review of this article.
Abstract—The increased understanding of right heart diseases
has led to more aggressive interventions to manage functional
tricuspid regurgitation (FTR). In some cases of FTR, pros-
thetic valve replacement is typically considered when con-
comitant organic components or signiﬁcant geometrical
distortions are involved in the pathology of the tricuspid
valve. However, little is known of the performance of current
devices in the right heart circulation. In this study, a novel
in vitro mock circulatory system that incorporated a realistic
tricuspid valve apparatus in a patient-speciﬁc silicon right
ventricle (RV) was designed and fabricated. The system was
calibrated to emulate severe FTR, enabling the investigation of
RV hemodynamics in pre- and post-implantation of tri-leaﬂet
tissue implant and bi-leaﬂet mechanical implant. 2D particle
imaging velocimetry was performed to visualize ﬂow and
quantify relevant hemodynamic parameters. While our results
showed all prosthetic implants improved cardiac output, these
implants also subjected the RV to increased turbulence level.
Our study also revealed that the implants did not create the
optimal behavior of ﬂuid transfer in the RV as we expected.
Among the implants tested, tissue implant created the most
dominant vortices, which persisted throughout diastole; its
observed strong negative vortex could lead to increase energy
expenditure due to undesired ﬂuid direction. In contrast, both
native valve and mechanical implant had both weaker vortex
formation as well as more signiﬁcant vortex dissipation.
Interestingly, the vortex dissipation of native valve was
associated with streamlined ﬂow pattern that tended towards
the pulmonary outlet, while the mechanical implant generated
more regions of ﬂow stagnation within the RV. These ﬁndings
heighten the imperative to improve designs of current heart
valves to be used in the right circulation.
Keywords—Bioprosthetic valve, Functional tricuspid regur-
gitation, Hemodynamics, Mechanical valve, Right ventricle,
Tricuspid valve, Valve replacement, Vortex, Prosthetic valve.
FTR Functional tricuspid regurgitation
LV Left ventricle
PIV Particle imaging velocimetry
PRSS Principal Reynolds shear stress
RV Right ventricle
TKE Turbulence kinetic energy
TR Tricuspid regurgitation
TV Tricuspid valve
VSS Viscous shear stress
Tricuspid regurgitation (TR) refers to the patho-
logical condition when the tricuspid leaﬂets of tricus-
pid valve (TV) do not coapt properly during
ventricular systole, leading to backﬂow of blood into
the atrium. Detectable TR can be as common as 80%
Mild and moderate TR can be
asymptotic and tolerated in many cases.
severe TR could lead to severe adverse consequences
and contribute to right heart failure.
The most com-
mon etiology is termed functional tricuspid regurgita-
tion (FTR), in which adverse ventricular remodelling
and/or tricuspid annular dilatation compromise the
valve functioning despite normal valvular apparatus
TR has been undertreated so far, and
surgical treatment of FTR remains the matter of con-
troversy with regard to diagnosis, indication of surgery
and surgical techniques.
prosthetic implants including tissue and mechanical
valves are being used to replace a malfunctioned TV.
Address correspondence to Hwa Liang Leo, Department of
Biomedical Engineering, National University of Singapore, Singa-
pore, Singapore. Electronic mail: firstname.lastname@example.org
Cardiovascular Engineering and Technology, Vol. 8, No. 4, December 2017 (
2017) pp. 401–418
2017 Biomedical Engineering Society