Flow Dynamic Factors Correlated With Device-Related Thrombosis After Left Atrial Appendage Occlusion.

Background: Device-related thrombosis (DRT) occurs in up to 4% of patients undergoing left atrial appendage occlusion (LAAO) and is associated with substantial morbidity and mortality. However, its pathophysiology, predictors, and optimal management remain unclear.

Objectives: This study aims to assess flow dynamic factors correlating to DRT.

FEops HEARTguide Patient-Specific Computational Simulations for WATCHMAN FLX Left Atrial Appendage Closure: A Retrospective Study.

Background: Three-dimensional transesophageal echocardiography (3D-TEE) is the primary imaging tool for left atrial appendage closure planning. The utility of cardiac computed tomography angiography (CCTA) and patient-specific computational models is unknown.

Objectives: The purpose of this study was to evaluate the accuracy of the FEops HEARTguide patient-specific computational modeling in predicting appropriate device size, location, and compression of the WATCHMAN FLX compared to intraprocedural 3D-TEE.

Force distribution within the frame of self-expanding transcatheter aortic valve: Insights from in-vivo finite element analysis.

We sought to assess the amount and distribution of force on the valve frame after transcatheter aortic valve replacement (TAVR) via patient-specific computer simulation. Patients successfully treated with the self-expanding Venus A-Valve and multislice computed tomography (MSCT) pre- and post-TAVR were retrospectively included. Patient-specific finite element models of the aortic root and prosthesis were constructed.

Mechanical and morphometric study of mitral valve chordae tendineae and related papillary muscle.

The mitral valve (MV) apparatus is a complex mechanical structure including annulus, valve leaflets, papillary muscles (PMs) and connected chordae tendineae. Chordae anchor to the papillary muscles to help the valve open and close properly during one cardiac cycle. It is of paramount importance to understand the functional, mechanical, and microstructural properties of mitral valve chordae and connecting PMs.

Automatic Detection of the Aortic Annular Plane and Coronary Ostia from Multidetector Computed Tomography.

Anatomic landmark detection is crucial during preoperative planning of transcatheter aortic valve implantation (TAVI) to select the proper device size and assess the risk of complications. The detection is currently a time-consuming manual process influenced by the image quality and subject to operator variability. In this work, we propose a novel automatic method to detect the relevant aortic landmarks from MDCT images using deep learning techniques.

The Impact of Size and Position of a Mechanical Expandable Transcatheter Aortic Valve: Novel Insights Through Computational Modelling and Simulation.

Transcatheter aortic valve implantation has become an established procedure to treat severe aortic stenosis. Correct device sizing/positioning is crucial for optimal outcome. Lotus valve sizing is based upon multiple aortic root dimensions.

A study on the efficacy of AFO stiffness prescriptions.

Purpose: Ankle foot orthosis (AFO) stiffness is a key characteristic that determines how much support or restraint an AFO can provide. Thus, the goal of the current study is twofold: (1) to quantify AFO prescriptions for a group of patients; (2) to evaluate what impact these AFO have on the push-off phase.

Method: Six patients were included in the study.

Optimization of a Transcatheter Heart Valve Frame Using Patient-Specific Computer Simulation.

Purpose: This study proposes a new framework to optimize the design of a transcatheter aortic valve through patient-specific finite element and fluid dynamics simulation.

Methods: Two geometrical parameters of the frame, the diameter at ventricular inflow and the height of the first row of cells, were examined using the central composite design. The effect of those parameters on postoperative complications was investigated by response surface methodology, and a Nonlinear Programming by Quadratic Lagrangian algorithm was used in the optimization.

A validated computational framework to evaluate the stiffness of 3D printed ankle foot orthoses.

The purpose of this study was to create and validate a standardized framework for the evaluation of the ankle stiffness of two designs of 3D printed ankle foot orthoses (AFOs). The creation of four finite element (FE) models allowed patient-specific quantification of the stiffness and stress distribution over their specific range of motion during the second rocker of the gait. Validation was performed by comparing the model outputs with the results obtained from a dedicated experimental setup, which showed an overall good agreement with a maximum relative error of 10.

Computational and experimental evaluation of the mechanical properties of ankle foot orthoses: A literature review.

Background: Ankle foot orthoses are external medical devices applied around the ankle joint area to provide stability to patients with neurological, muscular, and/or anatomical disabilities, with the aim of restoring a more natural gait pattern.

Study Design: This is a literature review.

Objectives: To provide a description of the experimental and computational methods present in the current literature for evaluating the mechanical properties of the ankle foot orthoses.

Kinematic boundary conditions substantially impact in silico ventricular function.

Computational cardiac mechanical models, individualized to the patient, have the potential to elucidate the fundamentals of cardiac (patho-)physiology, enable non-invasive quantification of clinically significant metrics (eg, stiffness, active contraction, work), and anticipate the potential efficacy of therapeutic cardiovascular intervention. In a clinical setting, however, the available imaging resolution is often limited, which limits cardiac models to focus on the ventricles, without including the atria, valves, and proximal arteries and veins. In such models, the absence of surrounding structures needs to be accounted for by imposing realistic kinematic boundary conditions, which, for prognostic purposes, are preferably generic and thus non-image derived.

A modular inverse elastostatics approach to resolve the pressure-induced stress state for in vivo imaging based cardiovascular modeling.

Patient-specific biomechanical modeling of the cardiovascular system is complicated by the presence of a physiological pressure load given that the imaged tissue is in a pre-stressed and -strained state. Neglect of this prestressed state into solid tissue mechanics models leads to erroneous metrics (e.g.

Evaluation of a modified Cheatham-Platinum stent for the treatment of aortic coarctation by finite element modelling.

Objectives: Stent implantation for the treatment of aortic coarctation has become a standard approach for the management of older children and adults. Criteria for optimal stent design and construction remain undefined. This study used computational modelling to compare the performance of two generations of the Cheatham-Platinum stent (NuMED, Hopkinton, NY, USA) deployed in aortic coarctation using finite element analysis.

From 4D Medical Images (CT, MRI, and Ultrasound) to 4D Structured Mesh Models of the Left Ventricular Endocardium for Patient-Specific Simulations.

With cardiovascular disease (CVD) remaining the primary cause of death worldwide, early detection of CVDs becomes essential. The intracardiac flow is an important component of ventricular function, motion kinetics, wash-out of ventricular chambers, and ventricular energetics. Coupling between Computational Fluid Dynamics (CFD) simulations and medical images can play a fundamental role in terms of patient-specific diagnostic tools.

Patient-Specific Computer Simulation to Elucidate the Role of Contact Pressure in the Development of New Conduction Abnormalities After Catheter-Based Implantation of a Self-Expanding Aortic Valve.

Background: The extent to which pressure generated by the valve on the aortic root plays a role in the genesis of conduction abnormalities after transcatheter aortic valve replacement (TAVR) is unknown. This study elucidates the role of contact pressure and contact pressure area in the development of conduction abnormalities after TAVR using patient-specific computer simulations.

Methods And Results: Finite-element computer simulations were performed to simulate TAVR of 112 patients who had undergone TAVR with the self-expanding CoreValve/Evolut R valve.

Erratum to: An in silico biomechanical analysis of the stent-esophagus interaction.

In the original publication of the article, Tables 2 and 3 were published with error. The correct tables are provided below (Tables 2, 3). The original version of the article has also been corrected.

An in silico biomechanical analysis of the stent-esophagus interaction.

Despite all technological innovations in esophageal stent design over the past 20 years, the association between the stent design's mechanical behavior and its effect on the clinical outcome has not yet been thoroughly explored. A parametric numerical model of a commercially available esophageal bioresorbable polymeric braided wire stent is set up, accounting for stent design aspects such as braiding angle, strut material, wire thickness, degradation and friction between the wires comprising a predictive tool on the device's mechanical behavior. Combining this tool with complex multilayered numerical models of the pathological in vivo stressed, actively contracting and buckling esophagus could provide clinicians and engineers with a patient-specific window into the mechanical aspects of stent-based esophageal intervention.

Procedure to describe clavicular motion.

Background: For many years, researchers have attempted to describe shoulder motions by using different mathematical methods. The aim of this study was to describe a procedure to quantify clavicular motion.

Methods: The procedure proposed for the kinematic analysis consists of 4 main processes: 3 transcortical pins in the clavicle, motion capture, obtaining 3-dimensional bone models, and data processing.

Impact of plaque type and side branch geometry on side branch compromise after provisional stent implantation: a simulation study.

Aims: Mechanisms of lumen compromise after provisional side branch (SB) stenting are poorly understood. In this study we aimed to investigate the impact of bifurcation angle, plaque composition, and procedural strategy on SB compromise.

Methods And Results: Computer simulations of stent implantation were performed in Medina (1,1,1) bifurcation models.

Automated femoral landmark extraction for optimal prosthesis placement in total hip arthroplasty.

The automated extraction of anatomical reference landmarks in the femoral volume may improve speed, precision, and accuracy of surgical procedures, such as total hip arthroplasty. These landmarks are often hard to achieve, even via surgical incision. In addition, it provides a presurgical guidance for prosthesis sizing and placement.