Multi-scale pulsatile CFD modeling of thrombus transport in a patient-specific LVAD implantation

Abstract

Purpose Predictive models implemented in medical procedures can potentially bring great benefit to patients and represent a step forward in targeted treatments based on a patient’s physiological condition. It is the purpose of this paper to outline such a model. Design/methodology/approach A multi-scale 0D-3D model based on patient specific geometry combines a 0-dimensional lumped parameter model (LPM) with a 3D computational fluid dynamics (CFD) analysis coupled in time, to obtain physiologically viable flow parameters. Findings A comparison of physiological data gathered from literature with flow-field measurements in this model shows the viability of this method in relation to potential predictions of pathological flows repercussions and candidate treatments. Research limitations/implications A limitation of the model is the absence of compliance in the walls in the CFD fluid domain; however, compliance of the peripheral vasculature is accounted for by the LPM. Currently, an attempt is in progress to extend this multi-scale model to account for the fluid-structure interaction of the ventricular assist device vasculature and hemodynamics. Originality/value This work reports on a predictive pulsatile flow model that can be used to investigate surgical alternatives to reduce strokes in LVADs.

Three-dimensional extent of flow stagnation in transcatheter heart valves

“…Hence, significant effort has been directed towards understanding, minimizing and avoiding thrombosis in the cardiovascular system and on implantable devices. Studies have progressed from extensive in vivo [16,18] and in vitro [19,20] studies to modern multi-scale numerical simulations [21,22]. Additionally, substantial focus is on identifying and defining metrics that characterize flow-mediated thrombogenic potential in the cardiovascular system.…”

Computational fluid dynamics investigation of the novel hybrid comprehensive stage II operation

“…30 A time-varying compliance abiding by an elastance function acts as a pump driving the flow in the LPM. 31 The LPM was tuned to produce a cardiac output for the nominal model of approximately 3 L/minute with cardiac cycle of 0.5 seconds. Owing to the presence of a VSD, the HCS2 has a nonnegligible aortic root flow output.…”

Parametric Investigation of an Injection-Jet Self-Powered Fontan Circulation

“…The boundary conditions (BC) at all inlets and outlets of the IJSassisted Fontan required by the computational fluid dynamics (CFD) flow solver are provided by a low-order lumped parameter model (LPM) of the peripheral circulation that is based on multidegree of freedom Windkessel compartment models previously described [32]. This circuit is tuned to replicate pressure and flow rate waveforms with documented patient data [47][48][49][50][51][52][53][54][55][56][57] and present the appropriate impedance to the flow solver presented by the peripheral circulation. The SV Fontan circulation is simplified by lumping peripheral vascular beds in several coupled beds that model arterial and venous beds separately.…”

“…3.4. IJS-Fenestration dynamic interaction: the flow ratio hysteresis loop This group's previous work [53][54][55][56][57][58][59][60][61][62][63] focused on time-averaged quantifications (over a heart cycle). Generally, this would be acceptable as the bottom line of this research effort mainly targets a mean IVC pressure drop.…”