Computational methods for the aortic heart valve and its replacements

Abstract

Replacement with a prosthetic device remains a major treatment option for the patients suffering from heart valve disease, with prevalence growing resulting from an ageing population. While the most popular replacement heart valve continues to be the bioprosthetic heart valve (BHV), its durability remains limited. There is thus a continued need to develop a general understanding of the underlying mechanisms limiting BHV durability to facilitate development of a more durable prosthesis. In this regard, computational models can play a pivotal role as they can evaluate our understanding of the underlying mechanisms and be used to optimize designs that may not always be intuitive. Areas covered: This review covers recent progress in computational models for the simulation of BHV, with a focus on aortic valve (AV) replacement. Recent contributions in valve geometry, leaflet material models, novel methods for numerical simulation, and applications to BHV optimization are discussed. This information should serve not only to infer reliable and dependable BHV function, but also to establish guidelines and insight for the design of future prosthetic valves by analyzing the influence of design, hemodynamics and tissue mechanics. Expert commentary: The paradigm of predictive modeling of heart valve prosthesis are becoming a reality which can simultaneously improve clinical outcomes and reduce costs. It can also lead to patient-specific valve design.

Fluid–Structure Interaction Models of Bioprosthetic Heart Valve Dynamics in an Experimental Pulse Duplicator

“…A fluid-structure interaction (FSI) approach is necessary to model heart valves across the full cardiac cycle [8]. Accounting for coupling between the flexible valve leaflets and the fluid flow is crucial in studying the e↵ect of vortices in the aortic sinuses, predicting fluid-induced shear stress on the leaflets, and assessing valve performance by quantifying the valve orifice area and regurgitation [9]. A widely used approach to simulating cardiovascular FSI is the arbitrary Lagrangian-Eulerian (ALE) method [10,11], which uses body-conforming meshes for the fluid and solid.…”

“…Methods also have been developed that combine features of ALE and IB-like approaches, including the hybrid fictitious domain/ALE method [22] and the immersogeometric (IMGA) method [9,[23][24][25][26]. These methods also seek to relax the need to use body-conforming discretizations.…”

Pre-Operative Modeling of Transcatheter Mitral Valve Replacement in a Surgical Heart Valve Bioprosthesis

“…In recent years, many studies on computer simulation of the valve dynamics have been reported to provide valuable information on the functional analysis of native and THV as well as the relationship between mechanical stresses and disease progression [7][8][9][10][11]. Numerical simulations are also being used for the initial optimization and design of THV before the prototypes are built, and expensive experimental and animal evaluations have been conducted [12,13]. This can potentially reduce the time-to-market application of THV in clinical practice.…”

Hemodynamic Effects of Concentric and Eccentric Outflow Graft of LVADs on the Aortic Valve

“…Computational analysis is an important method widely utilized to study the biomechanic state of the aortic valve. Many decoupled FE and computational fluid dynamic (CFD) methods are commonly used to investigate the aortic leaflet dynamics [15]. However, the structural and hemodynamic responses of the aortic valve could not be calculated using both approaches due to the strong coupling effects between the blood and flexible leaflets.…”