Impact of prosthetic mitral valve orientation on the ventricular flow field: Comparison using patient-specific computational fluid dynamics

Jonas Lantz,Sophia Bäck,Carl-Johan Carlhäll,Ann Bolger,Anders Persson,Matts Karlsson,Tino Ebbers

doi:10.1016/j.jbiomech.2020.110209

Jonas Lantz, Sophia Bäck + Show 5 more

Open Access

https://doi.org/10.1016/j.jbiomech.2020.110209

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Abstract

Significant mitral valve regurgitation creates progressive adverse remodeling of the left ventricle (LV). Replacement of the failing valve with a prosthesis generally improves patient outcomes but leaves the patient with non-physiological intracardiac flow patterns that might contribute to their future risk of thrombus formation and embolism.It has been suggested that the angular orientation of the implanted valve might modify the postoperative distortion of the intraventricular flow field. In this study, we investigated the effect of prosthetic valve orientation on LV flow patterns by using heart geometry from a patient with LV dysfunction and a competent native mitral valve to calculate intracardiac flow fields with computational fluid dynamics (CFD). Results were validated using in vivo 4D Flow MRI. The computed flow fields were compared to calculations following virtual implantation of a mechanical heart valve oriented in four different angles to assess the effect of leaflet position. Flow patterns were visualized in long- and short-axes and quantified with flow component analysis. In comparison to a native valve, valve implantation increased the proportion of the mitral inflow remaining in the basal region and further increased the residual volume in the apical area. Only slight changes due to valve orientation were observed.Using our numerical framework, we demonstrated quantitative changes in left ventricular blood flow due to prosthetic mitral replacement. This framework may be used to improve design of prosthetic heart valves and implantation procedures to minimize the potential for apical flow stasis, and potentially assist personalized treatment planning.

Highlights

The most serious complication related to mechanical heart valves is the formation of thrombus and thromboembolism (Chandran, 2010; Laplace et al, 2004; Sotiropoulos et al, 2016; Yoganathan et al, 2004), which requires long-term anticoagulant therapy
We examined the impact of prosthetic valve implantation and the specific valve orientation on left ventricular (LV) flow fields
To define the flow field prior to virtual mitral replacement, we utilized in vivo MRI and CT data to assess baseline conditions in a patient with a dilated, dysfunctional left ventricle and a competent native mitral valve

Summary

Introduction

It is widely accepted that mitral valve prostheses, mechanical valves, strongly affect left ventricular (LV) hemodynamics (Faludi et al, 2010; Garitey et al, 1995; Meschini et al, 2018; Nguyen et al, 2018; Pierrakos et al, 2004; Querzoli et al, 2010; Sotiropoulos et al, 2016; Yoganathan et al, 2004). ⇑ Corresponding author at: Department of Health, Medicine and Caring Sciences, quality of life generally improve after implantation of a prosthetic mechanical valve, long-term risks remain. The most serious complication related to mechanical heart valves is the formation of thrombus and thromboembolism (Chandran, 2010; Laplace et al, 2004; Sotiropoulos et al, 2016; Yoganathan et al, 2004), which requires long-term anticoagulant therapy. The risk of embolism has been reported to be higher for mechanical valves in the mitral position compared to other prosthetic types and valve locations (Cannegieter et al, 1994; Chandran, 2010).

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