Can TKA outcomes be predicted with computational simulation? Generation of a patient specific planning tool

Intracranial aneurysms appear as sac-like outpouchings of the cerebral vasculature wall; inflated by the pressure of the blood that fills them. They are relatively common and affect up to 5% of the adult population. Fortunately, most remain asymptomatic. However, there is a small but inherent risk of rupture: 0.1% to 1% of detected aneurysms rupture every year. If rupture does occur there is a 30% to 50% chance of fatality. Consequently, if an aneurysm is detected, clinical intervention may be deemed appropriate. Therapy is currently aimed at pre-rupture detection and preventative treatment. However, interventional procedures are not without risk to the patient. The improvement and optimization of interventional techniques is an important concern for patient welfare and is necessary for rationalisation of healthcare priorities. Hence there is a need to develop methodologies to assist in identifying those ICAs most at risk of rupture. We focus on the mathematical modelling and computational simulation of ICA evolution. Models must take into consideration: (i) the biomechanics of the arterial wall; (ii) the biology of the arterial wall and (iii) the complex interplay between (i) and (ii), i.e. the mechanobiology of the arterial wall. The ultimate ambition of such models is to aid clinical diagnosis on a patient-specific basis. However, due to the significant biological complexity coupled with limited histological information such models are still in their relative infancy. Current research focuses on simulating the evolution of an ICA with an aim to yield insight into the growth and remodelling (G&R) processes that give rise to inception, enlargement, stabilisation and rupture. We present a novel Fluid-Structure-Growth computational framework for modelling aneurysm evolution.

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Comparison Among Different High Porosity Stent Configurations: Hemodynamic Effects of Treatment in a Large Cerebral Aneurysm

Journal of Biomechanical Engineering ◽

10.1115/1.4026257 ◽

2014 ◽

Vol 136 (2) ◽

Cited By ~ 8

Author(s):

Breigh N. Roszelle ◽

Priya Nair ◽

L. Fernando Gonzalez ◽

M. Haithem Babiker ◽

Justin Ryan ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Simulation ◽

Cerebral Aneurysms ◽

Post Treatment ◽

Patient Specific ◽

High Porosity ◽

Velocity Magnitude ◽

Large Patient ◽

Aneurysm Model

Whether treated surgically or with endovascular techniques, large and giant cerebral aneurysms are particularly difficult to treat. Nevertheless, high porosity stents can be used to accomplish stent-assisted coiling and even standalone stent-based treatments that have been shown to improve the occlusion of such aneurysms. Further, stent assisted coiling can reduce the incidence of complications that sometimes result from embolic coiling (e.g., neck remnants and thromboembolism). However, in treating cerebral aneurysms at bifurcation termini, it remains unclear which configuration of high porosity stents will result in the most advantageous hemodynamic environment. The goal of this study was to compare how three different stent configurations affected fluid dynamics in a large patient-specific aneurysm model. Three common stent configurations were deployed into the model: a half-Y, a full-Y, and a crossbar configuration. Particle image velocimetry was used to examine post-treatment flow patterns and quantify root-mean-squared velocity magnitude (VRMS) within the aneurysmal sac. While each configuration did reduce VRMS within the aneurysm, the full-Y configuration resulted in the greatest reduction across all flow conditions (an average of 56% with respect to the untreated case). The experimental results agreed well with clinical follow up after treatment with the full-Y configuration; there was evidence of thrombosis within the sac from the stents alone before coil embolization was performed. A computational simulation of the full-Y configuration aligned well with the experimental and in vivo findings, indicating potential for clinically useful prediction of post-treatment hemodynamics. This study found that applying different stent configurations resulted in considerably different fluid dynamics in an anatomically accurate aneurysm model and that the full-Y configuration performed best. The study indicates that knowledge of how stent configurations will affect post-treatment hemodynamics could be important in interventional planning and demonstrates the capability for such planning based on novel computational tools.

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MRI-Based Three Dimensional Modeling of Stenting Procedure

Volume 2: Biomedical and Biotechnology Engineering; Nanoengineering for Medicine and Biology ◽

10.1115/imece2011-65583 ◽

2011 ◽

Author(s):

Shijia Zhao ◽

Linxia Gu ◽

Shailesh Ganpule

Keyword(s):

Computational Simulation ◽

Three Dimensional ◽

Patient Specific ◽

Open Cell ◽

Mechanical Responses ◽

Three Dimensional Modeling ◽

Dimensional Modeling ◽

Closed Cell ◽

Stenosed Artery ◽

3D Geometry

In this work, the stents-induced mechanical responses of a patient-specific common carotid artery (CCA) were evaluated through computational simulation. The realistic 3D geometry of the artery was constructed from the MRI data. Two types of self-expanding stent design (open-cell and closed-cell) were used to restore the blood flow inside the 60% stenosed artery. The resulting lumen gain, dog-boning effect and arterial stress were estimated. Results suggested that the artery was straightened after stent implantation, and the open-cell design led to bigger lumen gain, better conformability, and less dog-boning effect. This work may facilitate the development of new stent designs.

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Volumetric Flow at the Supraceliac and Infrarenal Levels in Patients With Abdominal Aortic Aneurysm: Waveforms and Allometric Scaling Relationships

ASME 2009 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2009-204269 ◽

2009 ◽

Cited By ~ 1

Author(s):

Andrea S. Les ◽

Janice J. Yeung ◽

Phillip M. Young ◽

Robert J. Herfkens ◽

Ronald L. Dalman ◽

...

Keyword(s):

Blood Flow ◽

Abdominal Aortic Aneurysm ◽

Aortic Aneurysm ◽

Boundary Conditions ◽

Computational Simulation ◽

Critical Role ◽

Healthy Person ◽

Patient Specific ◽

Hemodynamic Forces ◽

Abdominal Aortic

Hemodynamic forces are thought to play a critical role in abdominal aortic aneurysm (AAA) formation and growth, as well as in the migration and failure of aortic stent grafts. Computational simulation of blood flow enables the study of such hemodynamic forces; however, these simulations require accurate geometries and boundary conditions, usually in the form of flow and pressure data at specific locations. Although hundreds of computed tomography (CT) and magnetic resonance (MR) imaging studies of AAA geometry are performed daily in the clinical setting, flow information is difficult to obtain: It is not possible to reliably measure flow using CT, and while phase-contrast MRI (PC-MRI) can measure velocities, it is rarely used clinically for AAA patients. As a result, many AAA blood flow simulations use highly resolved patient-specific geometries, but may utilize literature-derived flows for inlet boundary conditions from a single, unrelated, sometimes healthy person of dissimilar body mass.

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Wall Shear Stress Prediction Using Computational Simulation on Patient Specific Artery with Aneurysm

MATEC Web of Conferences ◽

10.1051/matecconf/20141302036 ◽

2014 ◽

Vol 13 ◽

pp. 02036

Author(s):

Muhamad Yunus ◽

Anis Suhaila Shuib ◽

Tuan Mohammad Yusoff Shah ◽

Ku Zilati Ku Shaari ◽

Ahmad Sobri Muda

Keyword(s):

Shear Stress ◽

Wall Shear Stress ◽

Computational Simulation ◽

Patient Specific ◽

Stress Prediction ◽

Wall Shear

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The effect of pelvic tilt on three‐dimensional coverage of the femoral head: A computational simulation study using patient‐specific anatomy

The Anatomical Record ◽

10.1002/ar.24320 ◽

2019 ◽

Cited By ~ 1

Author(s):

Keisuke Uemura ◽

Penny R. Atkins ◽

Christopher L. Peters ◽

Andrew E. Anderson

Keyword(s):

Femoral Head ◽

Simulation Study ◽

Pelvic Tilt ◽

Computational Simulation ◽

Three Dimensional ◽

Patient Specific

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Abstract 15648: Quantitative Evaluation of Mitral Valve Dynamics for Improved Planning of Mitral Valve Repairs

Circulation ◽

10.1161/circ.130.suppl_2.15648 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Ahnryul Choi ◽

Yonghoon Rim ◽

Susan T Laing ◽

David D McPherson ◽

Hyunggun Kim

Keyword(s):

Stress Concentration ◽

Mitral Valve ◽

Stress Reduction ◽

Surgical Planning ◽

Computational Simulation ◽

Patient Specific ◽

Stress Concentrations ◽

Computational Evaluation ◽

Ring Annuloplasty ◽

Leaflet Coaptation

Introduction: Mitral valve (MV) repair with ring annuloplasty is the standard surgical technique for the treatment of mitral regurgitation (MR). Long-term studies report MR recurrence in up to 2-4% of repairs. We have developed a novel computational evaluation strategy to determine the biomechanical and physiologic characteristics of MV dynamics prior to and following virtual MV repair to help with optimal surgical planning. Methods: Virtual MV models from patients with large annular dilation and severe MR in the anterolateral region were created using 3D echocardiographic data sets. Two different types of annuloplasty rings were modeled in the simulation: Physio (flat) and Physio II (saddle-shaped). Proper ring size was determined using standard clinical guidelines. Computational simulations of MV function (pre- and post-repair) were performed using dynamic finite element methods. Coaptation ratio (CR) and structural stress distribution across the MVs were determined and compared. Results: Pathologic MVs demonstrated substantial anterolateral malcoaptation (CR=0.34, Fig. 1A). Following virtual ring annuloplasty, there was marked improvement in coaptation (CR=0.65 for Physio, CR=0.62 for Physio II). Pre-repair simulation revealed large stress concentrations over the posterior leaflet (Fig. 1B). Stress concentration decreased by 54% after virtual MV repair. The saddle-shaped Physio II ring demonstrated more evenly distributed stress reduction while the flat ring (Physio) more effectively increased leaflet coaptation. Conclusion: We have quantitatively evaluated patient-specific MV function before and after MV repair using a novel computational simulation protocol. Virtual ring annuloplasty simulation demonstrated sufficient restoration of leaflet coaptation and reduced stress concentration following repair. This simulation strategy has the potential for improved pre-surgical planning and intraoperative evaluation of MV repair.

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Three-Dimensional Regeneration of Patient-Derived Intestinal Organoid Epithelium in a Physiodynamic Mucosal Interface-on-a-Chip

Micromachines ◽

10.3390/mi11070663 ◽

2020 ◽

Vol 11 (7) ◽

pp. 663 ◽

Cited By ~ 1

Author(s):

Yong Cheol Shin ◽

Woojung Shin ◽

Domin Koh ◽

Alexander Wu ◽

Yoko M. Ambrosini ◽

...

Keyword(s):

Disease Modeling ◽

Computational Simulation ◽

Three Dimensional ◽

Gastrointestinal Diseases ◽

Patient Specific ◽

Epithelial Barrier Function ◽

Fecal Microbiome ◽

Particle Mixing ◽

Dynamic Cell ◽

Epithelial Layers

The regeneration of the mucosal interface of the human intestine is critical in the host–gut microbiome crosstalk associated with gastrointestinal diseases. The biopsy-derived intestinal organoids provide genetic information of patients with physiological cytodifferentiation. However, the enclosed lumen and static culture condition substantially limit the utility of patient-derived organoids for microbiome-associated disease modeling. Here, we report a patient-specific three-dimensional (3D) physiodynamic mucosal interface-on-a-chip (PMI Chip) that provides a microphysiological intestinal milieu under defined biomechanics. The real-time imaging and computational simulation of the PMI Chip verified the recapitulation of non-linear luminal and microvascular flow that simulates the hydrodynamics in a living human gut. The multiaxial deformations in a convoluted microchannel not only induced dynamic cell strains but also enhanced particle mixing in the lumen microchannel. Under this physiodynamic condition, an organoid-derived epithelium obtained from the patients diagnosed with Crohn’s disease, ulcerative colitis, or colorectal cancer independently formed 3D epithelial layers with disease-specific differentiations. Moreover, co-culture with the human fecal microbiome in an anoxic–oxic interface resulted in the formation of stochastic microcolonies without a loss of epithelial barrier function. We envision that the patient-specific PMI Chip that conveys genetic, epigenetic, and environmental factors of individual patients will potentially demonstrate the pathophysiological dynamics and complex host–microbiome crosstalk to target a patient-specific disease modeling.

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Patient-specific simulation of stent-graft deployment in type B aortic dissection: model development and validation

Biomechanics and Modeling in Mechanobiology ◽

10.1007/s10237-021-01504-x ◽

2021 ◽

Author(s):

Xiaoxin Kan ◽

Tao Ma ◽

Jing Lin ◽

Lu Wang ◽

Zhihui Dong ◽

...

Keyword(s):

Blood Pressure ◽

Aortic Dissection ◽

Stent Graft ◽

Aortic Wall ◽

Computational Simulation ◽

Model Complexity ◽

Patient Specific ◽

Uniaxial Tensile ◽

Type B ◽

Type B Aortic Dissection

AbstractThoracic endovascular aortic repair (TEVAR) has been accepted as the mainstream treatment for type B aortic dissection, but post-TEVAR biomechanical-related complications are still a major drawback. Unfortunately, the stent-graft (SG) configuration after implantation and biomechanical interactions between the SG and local aorta are usually unknown prior to a TEVAR procedure. The ability to obtain such information via personalised computational simulation would greatly assist clinicians in pre-surgical planning. In this study, a virtual SG deployment simulation framework was developed for the treatment for a complicated aortic dissection case. It incorporates patient-specific anatomical information based on pre-TEVAR CT angiographic images, details of the SG design and the mechanical properties of the stent wire, graft and dissected aorta. Hyperelastic material parameters for the aortic wall were determined based on uniaxial tensile testing performed on aortic tissue samples taken from type B aortic dissection patients. Pre-stress conditions of the aortic wall and the action of blood pressure were also accounted for. The simulated post-TEVAR configuration was compared with follow-up CT scans, demonstrating good agreement with mean deviations of 5.8% in local open area and 4.6 mm in stent strut position. Deployment of the SG increased the maximum principal stress by 24.30 kPa in the narrowed true lumen but reduced the stress by 31.38 kPa in the entry tear region where there was an aneurysmal expansion. Comparisons of simulation results with different levels of model complexity suggested that pre-stress of the aortic wall and blood pressure inside the SG should be included in order to accurately predict the deformation of the deployed SG.

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