Innovative Modeling Techniques and 3D Printing in Patients with Left Ventricular Assist Devices: A Bridge from Bench to Clinical Practice

Abstract

Left ventricular assist devices (LVAD) cause altered flow dynamics that may result in complications such as stroke, pump thrombosis, bleeding, or aortic regurgitation. Understanding altered flow dynamics is important in order to develop more efficient and durable pump configurations. In patients with LVAD, hemodynamic assessment is limited to imaging techniques such as echocardiography which precludes detailed assessment of fluid dynamics. In this review article, we present some innovative modeling techniques that are often used in device development or for research purposes, but have not been utilized clinically. Computational fluid dynamic (CFD) modeling is based on computer simulations and particle image velocimetry (PIV) employs ex vivo models that helps study fluid characteristics such as pressure, shear stress, and velocity. Both techniques may help elaborate our understanding of complications that occur with LVAD and could be potentially used in the future to troubleshoot LVAD-related alarms. These techniques coupled with 3D printing may also allow for patient-specific device implants, lowering the risk of complications increasing device durability.

A Review of the Complex Landscape of Stroke in Left Ventricular Assist Device Trials

“…Novel imaging techniques such as computational fluid dynamics have been used to study the complex hemodynamics of LVAD patients, whereby fluid motion is simulated ex vivo using certain computational assumptions instead of flow measurement. 36 It has been proposed that computational fluid dynamics could aide in personalized LVAD implantations and the management of pump complications. However, computational fluid dynamics has yet to be validated in clinical practice.…”

“…However, computational fluid dynamics has yet to be validated in clinical practice. 36 STROKE SEVERITY CLASSIFICATIONS. The mRS has been used across a variety of LVAD trials as a marker of stroke severity.…”

Making a Soft Elastic Pulsation Pump (SEPP)

“…A pulsatile pump is considered to be more in line with human biology. In addition, more applications of 3D printing technology in artificial heart development have been reported in the literature, which facilitate the fabrication of cavities of complex geometries [13][14][15][16]. In 2017, Cohrs et al first proposed a pneumatically actuated flexible artificial heart with a flow rate of 2.2 L/min when operated at 80 bpm [17].…”

Computational Fluid Dynamics Simulations of Mitral Paravalvular Leaks in Human Heart

“…In this study, we created a simplified model of the left ventricle (LV) based on a computed tomographic examination of a patient with a mitral PVL. Literature provides numerous examples that discuss the use of dynamic deformation of the LV in the blood flow simulations both in healthy and infarcted LVs, as well as in subjects with native, bioprosthetic, healthy, and regurgitant mitral valves, or with left ventricular assist devices (see, e.g., [ 17 , 18 , 19 , 20 , 21 ]). However, preparation of the heart geometry and calculations themselves are much more complex in the abovementioned examples than in the case of a simplified, universal LV geometry.…”