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Catalano C, Crascì F, Puleo S, Scuoppo R, Pasta S, Raffa GM. Computational fluid dynamics in cardiac surgery and perfusion: A review. Perfusion 2024:2676591241239277. [PMID: 38850015 DOI: 10.1177/02676591241239277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2024]
Abstract
Cardiovascular diseases persist as a leading cause of mortality and morbidity, despite significant advances in diagnostic and surgical approaches. Computational Fluid Dynamics (CFD) represents a branch of fluid mechanics widely used in industrial engineering but is increasingly applied to the cardiovascular system. This review delves into the transformative potential for simulating cardiac surgery procedures and perfusion systems, providing an in-depth examination of the state-of-the-art in cardiovascular CFD modeling. The study first describes the rationale for CFD modeling and later focuses on the latest advances in heart valve surgery, transcatheter heart valve replacement, aortic aneurysms, and extracorporeal membrane oxygenation. The review underscores the role of CFD in better understanding physiopathology and its clinical relevance, as well as the profound impact of hemodynamic stimuli on patient outcomes. By integrating computational methods with advanced imaging techniques, CFD establishes a quantitative framework for understanding the intricacies of the cardiac field, providing valuable insights into disease progression and treatment strategies. As technology advances, the evolving synergy between computational simulations and clinical interventions is poised to revolutionize cardiovascular care. This collaboration sets the stage for more personalized and effective therapeutic strategies. With its potential to enhance our understanding of cardiac pathologies, CFD stands as a promising tool for improving patient outcomes in the dynamic landscape of cardiovascular medicine.
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Affiliation(s)
- Chiara Catalano
- Department of Engineering, Università degli Studi di Palermo, Palermo, Italy
| | - Fabrizio Crascì
- Department of Engineering, Università degli Studi di Palermo, Palermo, Italy
- Department of Research, IRCCS-ISMETT, Palermo, Italy
| | - Silvia Puleo
- Department of Engineering, Università degli Studi di Palermo, Palermo, Italy
| | - Roberta Scuoppo
- Department of Engineering, Università degli Studi di Palermo, Palermo, Italy
| | - Salvatore Pasta
- Department of Engineering, Università degli Studi di Palermo, Palermo, Italy
- Department of Research, IRCCS-ISMETT, Palermo, Italy
| | - Giuseppe M Raffa
- Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, IRCCS-ISMETT, Palermo, Italy
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Balasubramanya A, Maes L, Rega F, Mazzi V, Morbiducci U, Famaey N, Degroote J, Segers P. Hemodynamics and wall shear metrics in a pulmonary autograft: Comparing a fluid-structure interaction and computational fluid dynamics approach. Comput Biol Med 2024; 176:108604. [PMID: 38761502 DOI: 10.1016/j.compbiomed.2024.108604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 05/02/2024] [Accepted: 05/11/2024] [Indexed: 05/20/2024]
Abstract
OBJECTIVE In young patients, aortic valve disease is often treated by placement of a pulmonary autograft (PA) which adapts to its new environment through growth and remodeling. To better understand the hemodynamic forces acting on the highly distensible PA in the acute phase after surgery, we developed a fluid-structure interaction (FSI) framework and comprehensively compared hemodynamics and wall shear-stress (WSS) metrics with a computational fluid dynamic (CFD) simulation. METHODS The FSI framework couples a prestressed non-linear hyperelastic arterial tissue model with a fluid model using the in-house coupling code CoCoNuT. Geometry, material parameters and boundary conditions are based on in-vivo measurements. Hemodynamics, time-averaged WSS (TAWSS), oscillatory shear index (OSI) and topological shear variation index (TSVI) are evaluated qualitatively and quantitatively for 3 different sheeps. RESULTS Despite systolic-to-diastolic volumetric changes of the PA in the order of 20 %, the point-by-point correlation of TAWSS and OSI obtained through CFD and FSI remains high (r > 0.9, p < 0.01) for TAWSS and (r > 0.8, p < 0.01) for OSI). Instantaneous WSS divergence patterns qualitatively preserve similarities, but large deformations of the PA leads to a decrease of the correlation between FSI and CFD resolved TSVI (r < 0.7, p < 0.01). Moderate co-localization between FSI and CFD is observed for low thresholds of TAWSS and high thresholds of OSI and TSVI. CONCLUSION FSI might be warranted if we were to use the TSVI as a mechano-biological driver for growth and remodeling of PA due to varying intra-vascular flow structures and near wall hemodynamics because of the large expansion of the PA.
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Affiliation(s)
| | - Lauranne Maes
- Department of Mechanical Engineering, KU Leuven, Leuven, Belgium
| | - Filip Rega
- Cardiac Surgery, Department of Cardiovascular Sciences, KU Leuven, Belgium
| | - Valentina Mazzi
- PolitoBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Umberto Morbiducci
- PolitoBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Nele Famaey
- Department of Mechanical Engineering, KU Leuven, Leuven, Belgium
| | - Joris Degroote
- Department of Electromechanical Systems and Metal Engineering, Ghent University, Ghent, Belgium
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Fandaros M, Kwok C, Wolf Z, Labropoulos N, Yin W. Patient-Specific Numerical Simulations of Coronary Artery Hemodynamics and Biomechanics: A Pathway to Clinical Use. Cardiovasc Eng Technol 2024:10.1007/s13239-024-00731-4. [PMID: 38710896 DOI: 10.1007/s13239-024-00731-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 04/29/2024] [Indexed: 05/08/2024]
Abstract
PURPOSE Numerical models that simulate the behaviors of the coronary arteries have been greatly improved by the addition of fluid-structure interaction (FSI) methods. Although computationally demanding, FSI models account for the movement of the arterial wall and more adequately describe the biomechanical conditions at and within the arterial wall. This offers greater physiological relevance over Computational Fluid Dynamics (CFD) models, which assume the walls do not move or deform. Numerical simulations of patient-specific cases have been greatly bolstered by the use of imaging modalities such as Computed Tomography Angiography (CTA), Magnetic Resonance Imaging (MRI), Optical Coherence Tomography (OCT), and Intravascular Ultrasound (IVUS) to reconstruct accurate 2D and 3D representations of artery geometries. The goal of this study was to conduct a comprehensive review on CFD and FSI models on coronary arteries, and evaluate their translational potential. METHODS This paper reviewed recent work on patient-specific numerical simulations of coronary arteries that describe the biomechanical conditions associated with atherosclerosis using CFD and FSI models. Imaging modality for geometry collection and clinical applications were also discussed. RESULTS Numerical models using CFD and FSI approaches are commonly used to study biomechanics within the vasculature. At high temporal and spatial resolution (compared to most cardiac imaging modalities), these numerical models can generate large amount of biomechanics data. CONCLUSIONS Physiologically relevant FSI models can more accurately describe atherosclerosis pathogenesis, and help to translate biomechanical assessment to clinical evaluation.
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Affiliation(s)
- Marina Fandaros
- Department of Biomedical Engineering, Stony Brook University, Bioengineering Building, Room 109, 11794, Stony Brook, NY, USA
| | - Chloe Kwok
- Department of Biomedical Engineering, Stony Brook University, Bioengineering Building, Room 109, 11794, Stony Brook, NY, USA
| | - Zachary Wolf
- Department of Biomedical Engineering, Stony Brook University, Bioengineering Building, Room 109, 11794, Stony Brook, NY, USA
| | - Nicos Labropoulos
- Department of Surgery, Stony Brook Medicine, 11794, Stony Brook, NY, USA
| | - Wei Yin
- Department of Biomedical Engineering, Stony Brook University, Bioengineering Building, Room 109, 11794, Stony Brook, NY, USA.
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Noël C, Settembre N. Near-wall hemodynamic parameters of finger arteries altered by hand-transmitted vibration. Comput Biol Med 2024; 168:107709. [PMID: 37992469 DOI: 10.1016/j.compbiomed.2023.107709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/05/2023] [Accepted: 11/15/2023] [Indexed: 11/24/2023]
Abstract
BACKGROUND Sustained exposure to high-level hand-transmitted vibrations may result in angioneurotic disorders, which partly originate from vibration-altered hemodynamics in the finger arteries when repeating these disturbances throughout working life. Hence, the aim of this study is to assess the most relevant hemodynamic descriptors in the digital arteries, determine the relationship between the latter and vibration features, and gain better understanding of the physiological mechanisms involved. METHODS An experimental setup, mainly comprised of an ultra-high frequency ultrasound scanner and a vibration shaker, was used to image the digital proper volar arteries of the forefinger. Raw ultrasound data were post-processed by custom-made numerical routines to supply a pulsatile fluid mechanics model for computing the hemodynamic descriptors. Twenty-four healthy volunteers participated in the measurement campaign. Classical statistical methods were then applied to the dataset and also the wavelet transform for calculating the signal power in the frequency bands matching cardiac, respiratory, myogenic and neurogenic activities. RESULTS The artery diameter, the wall shear stress - WSS - and the WSS temporal gradient - WSSTG - were found to be the most relevant descriptors. Vibration-induced WSS was divided by three compared to its basal value whatever the vibration frequency and it was proportional to log2 of the acceleration level. Marked increases in WSSTG when stopping vibration might also lead to adverse health effects. Vibration caused a drop in WSS power for the frequency band associated with the neurogenic activity of the sympathetic nervous system. CONCLUSION This study may pave the way for a new framework to prevent vibration-induced vascular risk.
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Affiliation(s)
- Christophe Noël
- Electromagnetism, Vibration, Optics laboratory, Institut national de recherche et de sécurité (INRS), Vandœuvre-lès-Nancy, France.
| | - Nicla Settembre
- Department of Vascular Surgery, Nancy University Hospital, University of Lorraine, France.
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Özcan C, Kocatürk Ö, Işlak C, Öztürk C. Integrated particle image velocimetry and fluid-structure interaction analysis for patient-specific abdominal aortic aneurysm studies. Biomed Eng Online 2023; 22:113. [PMID: 38044423 PMCID: PMC10693692 DOI: 10.1186/s12938-023-01179-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 11/23/2023] [Indexed: 12/05/2023] Open
Abstract
BACKGROUND Understanding the hemodynamics of an abdominal aortic aneurysm (AAA) is crucial for risk assessment and treatment planning. This study introduces a low-cost, patient-specific in vitro AAA model to investigate hemodynamics using particle image velocimetry (PIV) and flow-simulating circuit, validated through fluid-structure interaction (FSI) simulations. METHODS In this study, 3D printing was employed to manufacture a flexible patient-specific AAA phantom using a lost-core casting technique. A pulsatile flow circuit was constructed using off-the-shelf components. A particle image velocimetry (PIV) setup was built using an affordable laser source and global shutter camera, and finally, the flow field inside the AAA was analyzed using open-source software. Fluid-structure interaction (FSI) simulations were performed to enhance our understanding of the flow field, and the results were validated by PIV analysis. Both steady-state and transient flow conditions were investigated. RESULTS Our experimental setup replicated physiological conditions, analyzing arterial wall deformations and flow characteristics within the aneurysm. Under constant flow, peak wall deformations and flow velocities showed deviations within - 12% to + 27% and - 7% to + 5%, respectively, compared to FSI simulations. Pulsatile flow conditions further demonstrated a strong correlation (Pearson coefficient 0.85) in flow velocities and vectors throughout the cardiac cycle. Transient phenomena, particularly the formation and progression of vortex structures during systole, were consistently depicted between experimental and numerical models. CONCLUSIONS By bridging high-fidelity experimental observations with comprehensive computational analyses, this study underscores the potential of integrated methodologies in enhancing our understanding of AAA pathophysiology. The convergence of realistic AAA phantoms, precise PIV measurements at affordable cost point, and validated FSI models heralds a new paradigm in vascular research, with significant implications for personalized medicine and bioengineering innovations.
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Affiliation(s)
- Can Özcan
- Institute of Biomedical Engineering, Boğaziçi University, Kandilli Campus, Feza Gürsey Bld., Çengelköy, 34685, Istanbul, Turkey.
| | - Özgür Kocatürk
- Institute of Biomedical Engineering, Boğaziçi University, Kandilli Campus, Feza Gürsey Bld., Çengelköy, 34685, Istanbul, Turkey
| | - Civan Işlak
- Department of Radiology, Division of Neuroradiology, Cerrahpaşa Medical Faculty, Istanbul University Cerrahpaşa, Istanbul, Turkey
| | - Cengizhan Öztürk
- Institute of Biomedical Engineering, Boğaziçi University, Kandilli Campus, Feza Gürsey Bld., Çengelköy, 34685, Istanbul, Turkey
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Martínez A, Hoeijmakers M, Geronzi L, Morgenthaler V, Tomasi J, Rochette M, Biancolini ME. Effect of turbulence and viscosity models on wall shear stress derived biomarkers for aorta simulations. Comput Biol Med 2023; 167:107603. [PMID: 37922602 DOI: 10.1016/j.compbiomed.2023.107603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 09/12/2023] [Accepted: 10/17/2023] [Indexed: 11/07/2023]
Abstract
Ascending aorta simulations provide insight into patient-specific hemodynamic conditions. Numerous studies have assessed fluid biomarkers which show a potential to aid clinicians in the diagnosis process. Unfortunately, there exists a large disparity in the computational methodology used to model turbulence and viscosity. Recognizing this disparity, some authors focused on analysing the influence of either the turbulence or viscosity models on the biomarkers in order to quantify the importance of these model choices. However, no analysis has yet been done on their combined effect. In order to fully understand and quantify the effect of the computational methodology, an assessment of the combined effect of turbulence and viscosity model choice was performed. Our results show that (1) non-Newtonian viscosity has greater impact (2.9-5.0%) on wall shear stress than Large Eddy Simulation turbulence modelling (0.1-1.4%), (2) the contribution of non-Newtonian viscosity is amplified when combined with a subgrid-scale turbulence model, (3) wall shear stress is underestimated when considering Newtonian viscosity by 2.9-5.0% and (4) cycle-to-cycle variability can impact the results as much as the numerical model if insufficient cycles are performed. These results demonstrate that, when assessing the effect of computational methodologies, the resultant combined effect of the different modelling assumptions differs from the aggregated effect of the isolated modifications. Accurate aortic flow modelling requires non-Newtonian viscosity and Large Eddy Simulation turbulence modelling.
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Affiliation(s)
- Antonio Martínez
- University of Rome Tor Vergata, Rome, Italy; Ansys France, Villeurbanne, France.
| | | | - Leonardo Geronzi
- University of Rome Tor Vergata, Rome, Italy; Ansys France, Villeurbanne, France
| | | | - Jacques Tomasi
- University of Rennes, CHU Rennes, Inserm, LTSI-UMR 1099, F-35000, Rennes, France
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Mandigers TJ, Ramella A, Bissacco D, Domanin M, van Herwaarden JA, Heijmen R, Luraghi G, Migliavacca F, Trimarchi S. Thoracic Stent Graft Numerical Models To Virtually Simulate Thoracic Endovascular Aortic Repair: A Scoping Review. Eur J Vasc Endovasc Surg 2023; 66:784-796. [PMID: 37330201 DOI: 10.1016/j.ejvs.2023.06.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 05/23/2023] [Accepted: 06/06/2023] [Indexed: 06/19/2023]
Abstract
OBJECTIVE Pre-procedural planning of thoracic endovascular aortic repair (TEVAR) may implement computational adjuncts to predict technical and clinical outcomes. The aim of this scoping review was to explore the currently available TEVAR procedure and stent graft modelling options. DATA SOURCES PubMed (MEDLINE), Scopus, and Web of Science were systematically searched (English language, up to 9 December 2022) for studies presenting a virtual thoracic stent graft model or TEVAR simulation. REVIEW METHODS The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) was followed. Qualitative and quantitative data were extracted, compared, grouped, and described. Quality assessment was performed using a 16 item rating rubric. RESULTS Fourteen studies were included. Among the currently available in silico simulations of TEVAR, severe heterogeneity exists in study characteristics, methodological details, and evaluated outcomes. Ten studies (71.4%) were published during the last five years. Eleven studies (78.6%) included heterogeneous clinical data to reconstruct patient specific aortic anatomy and disease (e.g., type B aortic dissection, thoracic aortic aneurysm) from computed tomography angiography imaging. Three studies (21.4%) constructed idealised aortic models with literature input. The applied numerical methods consisted of computational fluid dynamics analysing aortic haemodynamics in three studies (21.4%) and finite element analysis analysing structural mechanics in the others (78.6%), including or excluding aortic wall mechanical properties. The thoracic stent graft was modelled as two separate components (e.g., graft, nitinol) in 10 studies (71.4%), as a one component homogenised approximation (n = 3, 21.4%), or including nitinol rings only (n = 1, 7.1%). Other simulation components included the catheter for virtual TEVAR deployment and numerous outcomes (e.g., Von Mises stresses, stent graft apposition, drag forces) were evaluated. CONCLUSION This scoping review identified 14 severely heterogeneous TEVAR simulation models, mostly of intermediate quality. The review concludes there is a need for continuous collaborative efforts to improve the homogeneity, credibility, and reliability of TEVAR simulations.
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Affiliation(s)
- Tim J Mandigers
- Section of Vascular Surgery, Cardio Thoracic Vascular Department, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy; Department of Vascular Surgery, University Medical Centre Utrecht, Utrecht, The Netherlands.
| | - Anna Ramella
- Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Milan, Italy
| | - Daniele Bissacco
- Section of Vascular Surgery, Cardio Thoracic Vascular Department, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Maurizio Domanin
- Section of Vascular Surgery, Cardio Thoracic Vascular Department, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy; Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
| | - Joost A van Herwaarden
- Department of Vascular Surgery, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Robin Heijmen
- Department of Cardiothoracic Surgery, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Giulia Luraghi
- Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Milan, Italy
| | - Francesco Migliavacca
- Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Milan, Italy
| | - Santi Trimarchi
- Section of Vascular Surgery, Cardio Thoracic Vascular Department, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy; Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
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Huang M, Guan R, Qiu J, Gnamey AJE, Wang Y, Tian H, Sun H, Shi H, Sun W, Jia X, Wu J. Identification of immune-related signatures and pathogenesis differences between thoracic aortic aneurysm patients with bicuspid versus tricuspid valves via weighted gene co-expression network analysis. PLoS One 2023; 18:e0292673. [PMID: 37883426 PMCID: PMC10602290 DOI: 10.1371/journal.pone.0292673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 09/26/2023] [Indexed: 10/28/2023] Open
Abstract
BACKGROUND Thoracic aortic aneurysm (TAA) occurs due to pathological aortal dilation, and both individuals with normal tricuspid aortic valves (TAV) or abnormal bicuspid aortic valves (BAV), the latter being a congenital condition, are at risk. However, some differences are present between TAA/BAV and TAA/TAV with respect to their pathophysiological processes and molecular mechanisms, but their exact nature is still mostly unknown. Therefore, it is necessary to elucidate TAA developmental differences among BAV vs. TAV patients. METHODS Publically-available gene expression datasets, aortic tissue derived from TAA/BAV and TAA/TAV individuals, were analyzed by weighted gene co-expression network analysis (WGCNA) to identify gene modules associated with those conditions. Gene Ontology (GO) enrichment analysis was performed on those modules to identify the enriched genes within those modules, which were verified by Gene Set Variation Analysis (GSVA) on a dataset derived from aortic smooth muscle cell gene expression between TAA/TAV and TAV/BAV patients. Immune cell infiltration patterns were then analyzed by CIBERSORT, and a protein-protein interaction (PPI) network was constructed based on WGCNA and enrichment analysis results to identify hub genes, followed by validation via stepwise regression analysis. Three signatures most strongly associated with TAA/TAV were confirmed by receiver operating characteristic (ROC) and decision curve analyses (DCA) between prior-established training and testing gene sets. RESULTS WGCNA delineated 2 gene modules being associated with TAA/TAV vs. TAA/BAV; both were enriched for immune-associated genes, such as those relating to immune responses, etc., under enrichment analysis. TAA/TAV and TAA/BAV tissues also had differing infiltrating immune cell proportions, particularly with respect to dendritic, mast and CD4 memory T cells. Identified three signatures, CD86, integrin beta 2 (ITGB2) and alpha M (ITGAM), as yielding the strongest associations with TAA/TAV onset, which was verified by areas under the curve (AUC) at levels approximating 0.8 or above under ROC analysis, indicating their predictive value for TAA/TAV onset. However, we did not examine possible confounding variables, so there are many alternative explanations for this association. CONCLUSIONS TAA/TAV pathogenesis was found to be more associated with immune-related gene expression compared to TAA/BAV, and the identification of three strongly-associated genes could facilitate their usage as future biomarkers for diagnosing the likelihood of TAA/TAV onset vs. TAA/BAV, as well as for developing future treatments.
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Affiliation(s)
- Min Huang
- Laboratory of Medical Genetics, Harbin Medical University, Harbin, Heilongjiang, China
- Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China (Harbin Medical University), Ministry of Education, Harbin, Heilongjiang, China
| | - Rong Guan
- Laboratory of Medical Genetics, Harbin Medical University, Harbin, Heilongjiang, China
- Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China (Harbin Medical University), Ministry of Education, Harbin, Heilongjiang, China
| | - Jiawei Qiu
- Laboratory of Medical Genetics, Harbin Medical University, Harbin, Heilongjiang, China
- Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China (Harbin Medical University), Ministry of Education, Harbin, Heilongjiang, China
| | - Abla Judith Estelle Gnamey
- Laboratory of Medical Genetics, Harbin Medical University, Harbin, Heilongjiang, China
- Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China (Harbin Medical University), Ministry of Education, Harbin, Heilongjiang, China
| | - Yusi Wang
- Laboratory of Medical Genetics, Harbin Medical University, Harbin, Heilongjiang, China
- Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China (Harbin Medical University), Ministry of Education, Harbin, Heilongjiang, China
| | - Hai Tian
- Future Medical Laboratory, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Haoran Sun
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, Heilongjiang, China
| | - Hongbo Shi
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, Heilongjiang, China
| | - Wenjing Sun
- Laboratory of Medical Genetics, Harbin Medical University, Harbin, Heilongjiang, China
- Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China (Harbin Medical University), Ministry of Education, Harbin, Heilongjiang, China
| | - Xueyuan Jia
- Laboratory of Medical Genetics, Harbin Medical University, Harbin, Heilongjiang, China
- Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China (Harbin Medical University), Ministry of Education, Harbin, Heilongjiang, China
| | - Jie Wu
- Laboratory of Medical Genetics, Harbin Medical University, Harbin, Heilongjiang, China
- Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China (Harbin Medical University), Ministry of Education, Harbin, Heilongjiang, China
- Future Medical Laboratory, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
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Marin-Castrillon DM, Geronzi L, Boucher A, Lin S, Morgant MC, Cochet A, Rochette M, Leclerc S, Ambarki K, Jin N, Aho LS, Lalande A, Bouchot O, Presles B. Segmentation of the aorta in systolic phase from 4D flow MRI: multi-atlas vs. deep learning. MAGMA (NEW YORK, N.Y.) 2023; 36:687-700. [PMID: 36800143 DOI: 10.1007/s10334-023-01066-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 11/26/2022] [Accepted: 01/24/2023] [Indexed: 02/18/2023]
Abstract
OBJECTIVE In the management of the aortic aneurysm, 4D flow magnetic resonance Imaging provides valuable information for the computation of new biomarkers using computational fluid dynamics (CFD). However, accurate segmentation of the aorta is required. Thus, our objective is to evaluate the performance of two automatic segmentation methods on the calculation of aortic wall pressure. METHODS Automatic segmentation of the aorta was performed with methods based on deep learning and multi-atlas using the systolic phase in the 4D flow MRI magnitude image of 36 patients. Using mesh morphing, isotopological meshes were generated, and CFD was performed to calculate the aortic wall pressure. Node-to-node comparisons of the pressure results were made to identify the most robust automatic method respect to the pressures obtained with a manually segmented model. RESULTS Deep learning approach presented the best segmentation performance with a mean Dice similarity coefficient and a mean Hausdorff distance (HD) equal to 0.92+/- 0.02 and 21.02+/- 24.20 mm, respectively. At the global level HD is affected by the performance in the abdominal aorta. Locally, this distance decreases to 9.41+/- 3.45 and 5.82+/- 6.23 for the ascending and descending thoracic aorta, respectively. Moreover, with respect to the pressures from the manual segmentations, the differences in the pressures computed from deep learning were lower than those computed from multi-atlas method. CONCLUSION To reduce biases in the calculation of aortic wall pressure, accurate segmentation is needed, particularly in regions with high blood flow velocities. Thus, the deep learning segmen-tation method should be preferred.
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Affiliation(s)
| | | | - Arnaud Boucher
- Imaging and Artificial Vision Research Laboratory, University of Burgundy, Dijon, France
| | - Siyu Lin
- Imaging and Artificial Vision Research Laboratory, University of Burgundy, Dijon, France
| | - Marie-Catherine Morgant
- Imaging and Artificial Vision Research Laboratory, University of Burgundy, Dijon, France
- Department of cardiovascular and thoracic surgery, University Hospital of Dijon, Dijon, France
| | - Alexandre Cochet
- Imaging and Artificial Vision Research Laboratory, University of Burgundy, Dijon, France
- Medical Imaging Department, University Hospital of Dijon, Dijon, France
| | | | - Sarah Leclerc
- Imaging and Artificial Vision Research Laboratory, University of Burgundy, Dijon, France
| | | | - Ning Jin
- Siemens Medical Solutions, Nancy, France
| | - Ludwig Serge Aho
- Department of Epidemiology and Hygiene, University Hospital of Dijon, Dijon, France
| | - Alain Lalande
- Imaging and Artificial Vision Research Laboratory, University of Burgundy, Dijon, France
- Medical Imaging Department, University Hospital of Dijon, Dijon, France
| | - Olivier Bouchot
- Imaging and Artificial Vision Research Laboratory, University of Burgundy, Dijon, France
- Department of cardiovascular and thoracic surgery, University Hospital of Dijon, Dijon, France
| | - Benoit Presles
- Imaging and Artificial Vision Research Laboratory, University of Burgundy, Dijon, France.
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Wang X, Carpenter HJ, Ghayesh MH, Kotousov A, Zander AC, Amabili M, Psaltis PJ. A review on the biomechanical behaviour of the aorta. J Mech Behav Biomed Mater 2023; 144:105922. [PMID: 37320894 DOI: 10.1016/j.jmbbm.2023.105922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/14/2023] [Accepted: 05/20/2023] [Indexed: 06/17/2023]
Abstract
Large aortic aneurysm and acute and chronic aortic dissection are pathologies of the aorta requiring surgery. Recent advances in medical intervention have improved patient outcomes; however, a clear understanding of the mechanisms leading to aortic failure and, hence, a better understanding of failure risk, is still missing. Biomechanical analysis of the aorta could provide insights into the development and progression of aortic abnormalities, giving clinicians a powerful tool in risk stratification. The complexity of the aortic system presents significant challenges for a biomechanical study and requires various approaches to analyse the aorta. To address this, here we present a holistic review of the biomechanical studies of the aorta by categorising articles into four broad approaches, namely theoretical, in vivo, experimental and combined investigations. Experimental studies that focus on identifying mechanical properties of the aortic tissue are also included. By reviewing the literature and discussing drawbacks, limitations and future challenges in each area, we hope to present a more complete picture of the state-of-the-art of aortic biomechanics to stimulate research on critical topics. Combining experimental modalities and computational approaches could lead to more comprehensive results in risk prediction for the aortic system.
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Affiliation(s)
- Xiaochen Wang
- School of Electrical and Mechanical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia.
| | - Harry J Carpenter
- School of Electrical and Mechanical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Mergen H Ghayesh
- School of Electrical and Mechanical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia.
| | - Andrei Kotousov
- School of Electrical and Mechanical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Anthony C Zander
- School of Electrical and Mechanical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Marco Amabili
- Department of Mechanical Engineering, McGill University, Montreal H3A 0C3, Canada
| | - Peter J Psaltis
- Adelaide Medical School, The University of Adelaide, Adelaide, South Australia 5005, Australia; Department of Cardiology, Central Adelaide Local Health Network, Adelaide, South Australia 5000, Australia; Vascular Research Centre, Heart Health Theme, South Australian Health & Medical Research Institute (SAHMRI), Adelaide, South Australia 5000, Australia
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11
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Xiao M, Wu J, Chen D, Wang C, Wu Y, Sun T, Chen J. Ascending Aortic Volume: A Feasible Indicator for Ascending Aortic Aneurysm Elective Surgery? Acta Biomater 2023:S1742-7061(23)00353-7. [PMID: 37356784 DOI: 10.1016/j.actbio.2023.06.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 06/19/2023] [Accepted: 06/20/2023] [Indexed: 06/27/2023]
Abstract
Diameter-based criterion have been widely adopted for preventive surgery of ascending thoracic aortic aneurysm (ATAA). However, recent and growing evidence has shown that diameter-based methods may not be sufficient for identifying patients who are at risk of an ATAA. In this study, fluid-structure interaction (FSI) analysis was performed on one-hundred ATAA geometries reconstructed from clinical data to examine the relationship between hemodynamic conditions, ascending aortic volume (AAV), ascending aortic curvature, and aortic ratios measured from the reconstructed 3D models. The simulated hemodynamic and biomechanical parameters were compared among different groups of ATAA geometries classified based on AAV. The ATAAs with enlarged AAV showed significantly compromised hemodynamic conditions and higher mechanical wall stress. The maximum oscillatory shear index (OSI), particle residence time (PRT) and wall stress (WS) were significantly higher in enlarged ATAAs compared with controls (0.498 [0.497, 0.499] vs 0.499 [0.498, 0.499], p = 0.002, 312.847 [207.445, 519.391] vs 996.047 [640.644, 1573.140], p < 0.001, 769.680 [668.745, 879.795] vs 1072.000 [873.060, 1280.000] kPa, p < 0.001, respectively). Values were reported as median with interquartile range (IQR). AAV was also found to be more strongly correlated with these parameters compared to maximum diameter. The correlation coefficient between AAV and average WS was as high as 0.92 (p < 0.004), suggesting that AAV might be a feasible risk identifier for ATAAs. STATEMENT OF SIGNIFICANCE: Ascending thoracic aortic aneurysm is associated with the risk of dissection or rupture, creating life-threatening conditions. Current surgical intervention guidelines are purely diameter based. Recently, many studies proposed to incorporate other morphological parameters into the current clinical guidelines to better prevent severe adverse aortic events like rupture or dissection. The purpose of this study is to gain a better understanding of the relationship between morphological parameters and hemodynamic parameters in ascending aortic aneurysms using fluid-solid-interaction analysis on patient-specific geometries. Our results suggest that ascending aortic volume may be a better indicator for surgical intervention as it shows a stronger association with pathogenic hemodynamic conditions.
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Affiliation(s)
- Meng Xiao
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhongshan 2nd Road, Guangzhou, China, 510000.; Department of Electrical and Computer Engineering, University of Alberta, 116 St & 85 Ave, Edmonton, AB, Canada, T6G 2R3..
| | - Jinlin Wu
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhongshan 2nd Road, Guangzhou, China, 510000..
| | - Duanduan Chen
- Department of Biomedical Engineering, Beijing Institute of Technology, No. 5, South Street, Zhongguancun, Beijing, China..
| | - Chenghu Wang
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhongshan 2nd Road, Guangzhou, China, 510000..
| | - Yanfen Wu
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhongshan 2nd Road, Guangzhou, China, 510000..
| | - Tucheng Sun
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhongshan 2nd Road, Guangzhou, China, 510000..
| | - Jie Chen
- Department of Electrical and Computer Engineering, University of Alberta, 116 St & 85 Ave, Edmonton, AB, Canada, T6G 2R3..
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12
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Wang X, Ghayesh MH, Kotousov A, Zander AC, Dawson JA, Psaltis PJ. Fluid-structure interaction study for biomechanics and risk factors in Stanford type A aortic dissection. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023:e3736. [PMID: 37258411 DOI: 10.1002/cnm.3736] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 04/04/2023] [Accepted: 05/16/2023] [Indexed: 06/02/2023]
Abstract
Aortic dissection is a life-threatening condition with a rising prevalence in the elderly population, possibly as a consequence of the increasing population life expectancy. Untreated aortic dissection can lead to myocardial infarction, aortic branch malperfusion or occlusion, rupture, aneurysm formation and death. This study aims to assess the potential of a biomechanical model in predicting the risks of a non-dilated thoracic aorta with Stanford type A dissection. To achieve this, a fully coupled fluid-structure interaction model was developed under realistic blood flow conditions. This model of the aorta was developed by considering three-dimensional artery geometry, multiple artery layers, hyperelastic artery wall, in vivo-based physiological time-varying blood velocity profiles, and non-Newtonian blood behaviours. The results demonstrate that in a thoracic aorta with Stanford type A dissection, the wall shear stress (WSS) is significantly low in the ascending aorta and false lumen, leading to potential aortic dilation and thrombus formation. The results also reveal that the WSS is highly related to blood flow patterns. The aortic arch region near the brachiocephalic and left common carotid artery is prone to rupture, showing a good agreement with the clinical reports. The results have been translated into their potential clinical relevance by revealing the role of the stress state, WSS and flow characteristics as the main parameters affecting lesion progression, including rupture and aneurysm. The developed model can be tailored for patient-specific studies and utilised as a predictive tool to estimate aneurysm growth and initiation of wall rupture inside the human thoracic aorta.
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Affiliation(s)
- Xiaochen Wang
- School of Mechanical Engineering, University of Adelaide, Adelaide, Australia
| | - Mergen H Ghayesh
- School of Mechanical Engineering, University of Adelaide, Adelaide, Australia
| | - Andrei Kotousov
- School of Mechanical Engineering, University of Adelaide, Adelaide, Australia
| | - Anthony C Zander
- School of Mechanical Engineering, University of Adelaide, Adelaide, Australia
| | - Joseph A Dawson
- Department of Vascular & Endovascular Surgery, Royal Adelaide Hospital, Adelaide, Australia
- Trauma Surgery Unit, Royal Adelaide Hospital, Adelaide, Australia
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
| | - Peter J Psaltis
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
- Vascular Research Centre, Lifelong Health Theme, South Australian Health & Medical Research Institute (SAHMRI), Adelaide, Australia
- Department of Cardiology, Central Adelaide Local Health Network, Adelaide, Australia
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13
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Silva MLFDA, Gonçalves SDEF, Haniel J, Lucas TC, Huebner R. Comparative study between 1-way and 2-way coupled fluid-structure interaction in numerical simulation of aortic arch aneurysms. AN ACAD BRAS CIENC 2023; 95:e20210859. [PMID: 37255166 DOI: 10.1590/0001-3765202320210859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 12/19/2022] [Indexed: 06/01/2023] Open
Abstract
Hemodynamic forces are related to pathological variations of the cardiovascular system, and numerical simulations for fluid-structure interaction have been systematically used to analyze the behavior of blood flow and the arterial wall in aortic aneurysms. This paper proposes a comparative analysis of 1-way and 2-way coupled fluid-structure interaction for aortic arch aneurysm. The coupling models of fluid-structure interaction were conducted using 3D geometry of the thoracic aorta from computed tomography. Hyperelastic anisotropic properties were estimated for the Holzapfel arterial wall model. The rheological behavior of the blood was modeled by the Carreau-Yasuda model. The results showed that the 1-way approach tends to underestimate von Mises stress, displacement, and strain over the entire cardiac cycle, compared to the 2-way approach. In contrast, the behavior of the variables of flow field, velocity, wall shear stress, and Reynolds number when coupled by the 1-way model was overestimated at the systolic moment and tends to be equal at the diastolic moment. The quantitative differences found, especially during the systole, suggest the use of 2-way coupling in numerical simulations of aortic arch aneurysms due to the hyperelastic nature of the arterial wall, which leads to a strong iteration between the fluid and the arterial wall.
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Affiliation(s)
- Mário Luis F DA Silva
- Programa de Pós-Graduação em Engenharia Mecânica, Universidade Federal de Minas Gerais, Departamento de Engenharia Mecânica, Avenida Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil
| | - Saulo DE Freitas Gonçalves
- Programa de Pós-Graduação em Engenharia Mecânica, Universidade Federal de Minas Gerais, Departamento de Engenharia Mecânica, Avenida Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil
| | - Jonathas Haniel
- Programa de Pós-Graduação em Engenharia Mecânica, Universidade Federal de Minas Gerais, Departamento de Engenharia Mecânica, Avenida Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil
| | - Thabata C Lucas
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Departamento de Enfermagem, MGC 367, km 583, 5000, Alto da Jacuba, 39100-000 Diamantina, MG, Brazil
| | - Rudolf Huebner
- Universidade Federal de Minas Gerais, Departamento de Engenharia Mecânica, Avenida Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil
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14
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Saitta S, Maga L, Armour C, Votta E, O'Regan DP, Salmasi MY, Athanasiou T, Weinsaft JW, Xu XY, Pirola S, Redaelli A. Data-driven generation of 4D velocity profiles in the aneurysmal ascending aorta. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 233:107468. [PMID: 36921465 DOI: 10.1016/j.cmpb.2023.107468] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 02/15/2023] [Accepted: 03/05/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND AND OBJECTIVE Numerical simulations of blood flow are a valuable tool to investigate the pathophysiology of ascending thoratic aortic aneurysms (ATAA). To accurately reproduce in vivo hemodynamics, computational fluid dynamics (CFD) models must employ realistic inflow boundary conditions (BCs). However, the limited availability of in vivo velocity measurements, still makes researchers resort to idealized BCs. The aim of this study was to generate and thoroughly characterize a large dataset of synthetic 4D aortic velocity profiles sampled on a 2D cross-section along the ascending aorta with features similar to clinical cohorts of patients with ATAA. METHODS Time-resolved 3D phase contrast magnetic resonance (4D flow MRI) scans of 30 subjects with ATAA were processed through in-house code to extract anatomically consistent cross-sectional planes along the ascending aorta, ensuring spatial alignment among all planes and interpolating all velocity fields to a reference configuration. Velocity profiles of the clinical cohort were extensively characterized by computing flow morphology descriptors of both spatial and temporal features. By exploiting principal component analysis (PCA), a statistical shape model (SSM) of 4D aortic velocity profiles was built and a dataset of 437 synthetic cases with realistic properties was generated. RESULTS Comparison between clinical and synthetic datasets showed that the synthetic data presented similar characteristics as the clinical population in terms of key morphological parameters. The average velocity profile qualitatively resembled a parabolic-shaped profile, but was quantitatively characterized by more complex flow patterns which an idealized profile would not replicate. Statistically significant correlations were found between PCA principal modes of variation and flow descriptors. CONCLUSIONS We built a data-driven generative model of 4D aortic inlet velocity profiles, suitable to be used in computational studies of blood flow. The proposed software system also allows to map any of the generated velocity profiles to the inlet plane of any virtual subject given its coordinate set.
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Affiliation(s)
- Simone Saitta
- Department of Information, Electronics and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Ludovica Maga
- Department of Information, Electronics and Bioengineering, Politecnico di Milano, Milan, Italy; Department of Chemical Engineering, Imperial College London, London, UK
| | - Chloe Armour
- Department of Chemical Engineering, Imperial College London, London, UK
| | - Emiliano Votta
- Department of Information, Electronics and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Declan P O'Regan
- MRC London Institute of Medical Sciences, Imperial College London, London, United Kingdom
| | - M Yousuf Salmasi
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Thanos Athanasiou
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Jonathan W Weinsaft
- Department of Medicine (Cardiology), Weill Cornell College, New York, NY, USA
| | - Xiao Yun Xu
- Department of Chemical Engineering, Imperial College London, London, UK
| | - Selene Pirola
- Department of Chemical Engineering, Imperial College London, London, UK; Department of BioMechanical Engineering, 3mE Faculty, Delft University of Technology, Delft, Netherlands.
| | - Alberto Redaelli
- Department of Information, Electronics and Bioengineering, Politecnico di Milano, Milan, Italy
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15
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The Finite Element Analysis Research on Microneedle Design Strategy and Transdermal Drug Delivery System. Pharmaceutics 2022; 14:pharmaceutics14081625. [PMID: 36015251 PMCID: PMC9413279 DOI: 10.3390/pharmaceutics14081625] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/28/2022] [Accepted: 07/28/2022] [Indexed: 02/04/2023] Open
Abstract
Microneedles (MNs) as a novel transdermal drug delivery system have shown great potential for therapeutic and disease diagnosis applications by continually providing minimally invasive, portable, cost-effective, high bioavailability, and easy-to-use tools compared to traditional parenteral administrations. However, microneedle transdermal drug delivery is still in its infancy. Many research studies need further in-depth exploration, such as safety, structural characteristics, and drug loading performance evaluation. Finite element analysis (FEA) uses mathematical approximations to simulate real physical systems (geometry and load conditions). It can simplify complex engineering problems to guide the precise preparation and potential industrialization of microneedles, which has attracted extensive attention. This article introduces FEA research for microneedle transdermal drug delivery systems, focusing on microneedle design strategy, skin mechanics models, skin permeability, and the FEA research on drug delivery by MNs.
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16
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Inversion of Left Atrial Appendage Will Cause Compressive Stresses in the Tissue: Simulation Study of Potential Therapy. J Pers Med 2022; 12:jpm12060883. [PMID: 35743668 PMCID: PMC9225454 DOI: 10.3390/jpm12060883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/22/2022] [Accepted: 05/26/2022] [Indexed: 02/04/2023] Open
Abstract
In atrial fibrillation (AF), thromboembolic events can result from the particular conformation of the left atrial appendage (LAA) bearing increased clot formation and accumulation. Current therapies to reduce the risk of adverse events rely on surgical exclusion or percutaneous occlusion, each of which has drawbacks limiting application and efficacy. We sought to quantify the hemodynamic and structural loads of a novel potential procedure to partially invert the “dead” LAA space to eliminate the auricle apex where clots develop. A realistic left atrial geometry was first achieved from the heart anatomy of the Living Heart Human Model (LHHM) and then the left atrial appendage inversion (LAAI) was simulated by finite-element analysis. The LAAI procedure was simulated by pulling the elements at the LAA tip and prescribing a displacement motion along a predefined path. The deformed configuration was then used to develop a computational flow analysis of LAAI. Results demonstrated that the inverted LAA wall undergoes a change in the stress distribution from tensile to compressive in the inverted appendage, and this can lead to resorption of the LAA tissue as per a reduced stress/resorption relationship. Computational flow analyses highlighted a slightly nested low-flow velocity pattern for the inverted LAA with minimal differences from that of a model without inversion of the LAA apex. Our study revealed important insights into the biomechanics of LAAI and demonstrated the inversion of the stress field (from tensile to compressive), which &can ultimately lead the long-term resorption of the LAA.
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17
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Williamson PN, Docherty PD, Yazdi SG, Khanafer A, Kabaliuk N, Jermy M, Geoghegan PH. Review of the Development of Hemodynamic Modeling Techniques to Capture Flow Behavior in Arteries Affected by Aneurysm, Atherosclerosis, and Stenting. J Biomech Eng 2022; 144:1128816. [PMID: 34802061 DOI: 10.1115/1.4053082] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Indexed: 02/05/2023]
Abstract
Cardiovascular diseases (CVDs) are the leading cause of death in the developed world. CVD can include atherosclerosis, aneurysm, dissection, or occlusion of the main arteries. Many CVDs are caused by unhealthy hemodynamics. Some CVDs can be treated with the implantation of stents and stent grafts. Investigations have been carried out to understand the effects of stents and stent grafts have on arteries and the hemodynamic changes post-treatment. Numerous studies on stent hemodynamics have been carried out using computational fluid dynamics (CFD) which has yielded significant insight into the effect of stent mesh design on near-wall blood flow and improving hemodynamics. Particle image velocimetry (PIV) has also been used to capture behavior of fluids that mimic physiological hemodynamics. However, PIV studies have largely been restricted to unstented models or intra-aneurysmal flow rather than peri or distal stent flow behaviors. PIV has been used both as a standalone measurement method and as a comparison to validate the CFD studies. This article reviews the successes and limitations of CFD and PIV-based modeling methods used to investigate the hemodynamic effects of stents. The review includes an overview of physiology and relevant mechanics of arteries as well as consideration of boundary conditions and the working fluids used to simulate blood for each modeling method along with the benefits and limitations introduced.
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Affiliation(s)
- Petra N Williamson
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Paul D Docherty
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Sina G Yazdi
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Adib Khanafer
- Vascular, Endovascular, and Renal Transplant Unit, Christchurch Hospital, Canterbury District Health Board, Riccarton Avenue, Christchurch 8053, New Zealand; Christchurch School of Medicine, University of Otago, Dunedin 9016, New Zealand
| | - Natalia Kabaliuk
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Mark Jermy
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Patrick H Geoghegan
- School of Life and Health Sciences, Aston University, Birmingham B4 7ET, UK; Department of Mechanical and Industrial Engineering, University of South Africa, Johannesburg 2006, South Africa
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18
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Celi S, Vignali E, Capellini K, Gasparotti E. On the Role and Effects of Uncertainties in Cardiovascular in silico Analyses. FRONTIERS IN MEDICAL TECHNOLOGY 2022; 3:748908. [PMID: 35047960 PMCID: PMC8757785 DOI: 10.3389/fmedt.2021.748908] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/14/2021] [Indexed: 12/13/2022] Open
Abstract
The assessment of cardiovascular hemodynamics with computational techniques is establishing its fundamental contribution within the world of modern clinics. Great research interest was focused on the aortic vessel. The study of aortic flow, pressure, and stresses is at the basis of the understanding of complex pathologies such as aneurysms. Nevertheless, the computational approaches are still affected by sources of errors and uncertainties. These phenomena occur at different levels of the computational analysis, and they also strongly depend on the type of approach adopted. With the current study, the effect of error sources was characterized for an aortic case. In particular, the geometry of a patient-specific aorta structure was segmented at different phases of a cardiac cycle to be adopted in a computational analysis. Different levels of surface smoothing were imposed to define their influence on the numerical results. After this, three different simulation methods were imposed on the same geometry: a rigid wall computational fluid dynamics (CFD), a moving-wall CFD based on radial basis functions (RBF) CFD, and a fluid-structure interaction (FSI) simulation. The differences of the implemented methods were defined in terms of wall shear stress (WSS) analysis. In particular, for all the cases reported, the systolic WSS and the time-averaged WSS (TAWSS) were defined.
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Affiliation(s)
- Simona Celi
- BioCardioLab, UOC Bioingegneria, Fondazione Toscana Gabriele Monasterio, Massa, Italy
| | - Emanuele Vignali
- BioCardioLab, UOC Bioingegneria, Fondazione Toscana Gabriele Monasterio, Massa, Italy
| | - Katia Capellini
- BioCardioLab, UOC Bioingegneria, Fondazione Toscana Gabriele Monasterio, Massa, Italy.,Department of Information Engineering, University of Pisa, Pisa, Italy
| | - Emanuele Gasparotti
- BioCardioLab, UOC Bioingegneria, Fondazione Toscana Gabriele Monasterio, Massa, Italy.,Department of Information Engineering, University of Pisa, Pisa, Italy
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19
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Atlas-Based Evaluation of Hemodynamic in Ascending Thoracic Aortic Aneurysms. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app12010394] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Atlas-based analyses of patients with cardiovascular diseases have recently been explored to understand the mechanistic link between shape and pathophysiology. The construction of probabilistic atlases is based on statistical shape modeling (SSM) to assess key anatomic features for a given patient population. Such an approach is relevant to study the complex nature of the ascending thoracic aortic aneurysm (ATAA) as characterized by different patterns of aortic shapes and valve phenotypes. This study was carried out to develop an SSM of the dilated aorta with both bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV), and then assess the computational hemodynamic of virtual models obtained by the deformation of the mean template for specific shape boundaries (i.e., ±1.5 standard deviation, σ). Simulations demonstrated remarkable changes in the velocity streamlines, blood pressure, and fluid shear stress with the principal shape modes such as the aortic size (Mode 1), vessel tortuosity (Mode 2), and aortic valve morphologies (Mode 3). The atlas-based disease assessment can represent a powerful tool to reveal important insights on ATAA-derived hemodynamic, especially for aneurysms which are considered to have borderline anatomies, and thus challenging decision-making. The utilization of SSMs for creating probabilistic patient cohorts can facilitate the understanding of the heterogenous nature of the dilated ascending aorta.
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20
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Vignali E, Gasparotti E, Celi S, Avril S. Fully-Coupled FSI Computational Analyses in the Ascending Thoracic Aorta Using Patient-Specific Conditions and Anisotropic Material Properties. Front Physiol 2021; 12:732561. [PMID: 34744774 PMCID: PMC8564074 DOI: 10.3389/fphys.2021.732561] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/17/2021] [Indexed: 12/27/2022] Open
Abstract
Computational hemodynamics has become increasingly important within the context of precision medicine, providing major insight in cardiovascular pathologies. However, finding appropriate compromise between speed and accuracy remains challenging in computational hemodynamics for an extensive use in decision making. For example, in the ascending thoracic aorta, interactions between the blood and the aortic wall must be taken into account for the sake of accuracy, but these fluid structure interactions (FSI) induce significant computational costs, especially when the tissue exhibits a hyperelastic and anisotropic response. The objective of the current study is to use the Small On Large (SOL) theory to linearize the anisotropic hyperelastic behavior in order to propose a reduced-order model for FSI simulations of the aorta. The SOL method is tested for fully-coupled FSI simulations in a patient-specific aortic geometry presenting an Ascending Thoracic Aortic Aneurysm (aTAA). The same model is also simulated with a fully-coupled FSI with non-linear material behavior, without SOL linearization. Eventually, the results and computational times with and without the SOL are compared. The SOL approach is demonstrated to provide a significant reduction of computational costs for FSI analysis in the aTAA, and the results in terms of stress state distribution are comparable. The method is implemented in ANSYS and will be further evaluated for clinical applications.
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Affiliation(s)
- Emanuele Vignali
- BioCardioLab, UOC Bioingegneria, Fondazione Toscana Gabriele Monasterio, Massa, Italy
| | - Emanuele Gasparotti
- BioCardioLab, UOC Bioingegneria, Fondazione Toscana Gabriele Monasterio, Massa, Italy
| | - Simona Celi
- BioCardioLab, UOC Bioingegneria, Fondazione Toscana Gabriele Monasterio, Massa, Italy
| | - Stéphane Avril
- Mines Saint-Etienne, Université de Lyon, INSERM, SaInBioSE U1059, Saint-Étienne, France
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21
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Patient-Specific Analysis of Ascending Thoracic Aortic Aneurysm with the Living Heart Human Model. Bioengineering (Basel) 2021; 8:bioengineering8110175. [PMID: 34821741 PMCID: PMC8615119 DOI: 10.3390/bioengineering8110175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/26/2021] [Accepted: 11/03/2021] [Indexed: 01/11/2023] Open
Abstract
In ascending thoracic aortic aneurysms (ATAAs), aneurysm kinematics are driven by ventricular traction occurring every heartbeat, increasing the stress level of dilated aortic wall. Aortic elongation due to heart motion and aortic length are emerging as potential indicators of adverse events in ATAAs; however, simulation of ATAA that takes into account the cardiac mechanics is technically challenging. The objective of this study was to adapt the realistic Living Heart Human Model (LHHM) to the anatomy and physiology of a patient with ATAA to assess the role of cardiac motion on aortic wall stress distribution. Patient-specific segmentation and material parameter estimation were done using preoperative computed tomography angiography (CTA) and ex vivo biaxial testing of the harvested tissue collected during surgery. The lumped-parameter model of systemic circulation implemented in the LHHM was refined using clinical and echocardiographic data. The results showed that the longitudinal stress was highest in the major curvature of the aneurysm, with specific aortic quadrants having stress levels change from tensile to compressive in a transmural direction. This study revealed the key role of heart motion that stretches the aortic root and increases ATAA wall tension. The ATAA LHHM is a realistic cardiovascular platform where patient-specific information can be easily integrated to assess the aneurysm biomechanics and potentially support the clinical management of patients with ATAAs.
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Du J, Shi J, Liu J, Deng C, Shen J, Wang Q. Hemodynamic analysis of hepatic arteries for the early evaluation of hepatic fibrosis in biliary atresia. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 211:106400. [PMID: 34551379 DOI: 10.1016/j.cmpb.2021.106400] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND AND OBJECTIVE Hepatic fibrosis is the prominent characteristic of biliary atresia (BA), may even progress continually after Kasai procedure (KP). BA, as a devastating pediatric hepatic disease, mainly leads to newborn cholestasis, even liver cirrhosis, eventually hepatic failure. Earlier diagnosis of hepatic fibrosis, which used to be detected by liver biopsy commonly, is consistent with better outcomes of KP. Due to potential risks and uncertainty of liver biopsy, it is an urge to seek a safer and more precise evaluation method as alternative. The purpose of this study is to investigate the hemodynamics of hepatic artery (HA) in hepatic fibrosis of early BA based on computational fluid dynamics (CFD) for evaluating the value of CFD for hepatic fibrosis diagnosis. METHODS 40 patients were divided into three groups, including the control group, the abnormal liver function group and the mild to moderate hepatic fibrosis group. CFD was applied to quantify primary hemodynamic parameters of HA and related arteries, including blood flow distribution ratio (FDR), pressure, wall shear stress (WSS) and energy loss (EL). Statistical analyses were also performed to compare the differences amongst these above groups. RESULTS With the progression of hepatic fibrosis, the increasing tendency of hemodynamic parameters values of HA and related arteries were observed. Values of FDR, pressure, WSS and EL of the mild to moderate group was higher than those of the control group and the abnormal liver function group. There were significant differences on FDRAA, FDRHA and EL between the control group and the mild to moderate hepatic fibrosis group (t = 0.037, 0.030 and <0.001, P < 0.05). CONCLUSION Significant variations of HA hemodynamics acquired by CFD between the control group and the mild to moderate hepatic fibrosis group demonstrated the relationship between the progression of hepatic fibrosis and the hemodynamic disorder, and suggested that CFD had the potential to assist the diagnosis of hepatic fibrosis in early BA.
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Affiliation(s)
- Jun Du
- Department of Medical Imaging, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, 1678 Dongfang Road, Shanghai 200127, China
| | - Jing Shi
- Department of Medical Imaging, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, 1678 Dongfang Road, Shanghai 200127, China
| | - Jinlong Liu
- Department of Cardiothoracic Surgery, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Engineering Research Center of Virtual Reality of Structural Heart Disease, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Pediatric Translational Medicine, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chaohui Deng
- Department of Gastroenterology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Juanya Shen
- Department of Cardiothoracic Surgery, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Engineering Research Center of Virtual Reality of Structural Heart Disease, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Institute of Pediatric Translational Medicine, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qian Wang
- Department of Medical Imaging, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, 1678 Dongfang Road, Shanghai 200127, China.
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Manchester EL, Pirola S, Salmasi MY, O'Regan DP, Athanasiou T, Xu XY. Analysis of Turbulence Effects in a Patient-Specific Aorta with Aortic Valve Stenosis. Cardiovasc Eng Technol 2021; 12:438-453. [PMID: 33829405 PMCID: PMC8354935 DOI: 10.1007/s13239-021-00536-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 03/18/2021] [Indexed: 10/26/2022]
Abstract
Blood flow in the aorta is often assumed laminar, however aortic valve pathologies may induce transition to turbulence and our understanding of turbulence effects is incomplete. The aim of the study was to provide a detailed analysis of turbulence effects in aortic valve stenosis (AVS). METHODS Large-eddy simulation (LES) of flow through a patient-specific aorta with AVS was conducted. Magnetic resonance imaging (MRI) was performed and used for geometric reconstruction and patient-specific boundary conditions. Computed velocity field was compared with 4D flow MRI to check qualitative and quantitative consistency. The effect of turbulence was evaluated in terms of fluctuating kinetic energy, turbulence-related wall shear stress (WSS) and energy loss. RESULTS Our analysis suggested that turbulence was induced by a combination of a high velocity jet impinging on the arterial wall and a dilated ascending aorta which provided sufficient space for turbulence to develop. Turbulent WSS contributed to 40% of the total WSS in the ascending aorta and 38% in the entire aorta. Viscous and turbulent irreversible energy losses accounted for 3.9 and 2.7% of the total stroke work, respectively. CONCLUSIONS This study demonstrates the importance of turbulence in assessing aortic haemodynamics in a patient with AVS. Neglecting the turbulent contribution to WSS could potentially result in a significant underestimation of the total WSS. Further work is warranted to extend the analysis to more AVS cases and patients with other aortic valve diseases.
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Affiliation(s)
- Emily L Manchester
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Selene Pirola
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Mohammad Yousuf Salmasi
- Department of Surgery and Cancer, St Mary's Hospital, Imperial College London, London, W2 1NY, UK
| | - Declan P O'Regan
- Hammersmith Hospital, MRC London Institute of Medical Sciences Imperial College London, London, W12 0HS, UK
| | - Thanos Athanasiou
- Department of Surgery and Cancer, St Mary's Hospital, Imperial College London, London, W2 1NY, UK
| | - Xiao Yun Xu
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
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A CFD Numerical Study to Evaluate the Effect of Deck Roughness and Length on Shipping Water Loading. WATER 2021. [DOI: 10.3390/w13152063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Shipping water events that propagate over the decks of marine structures can generate significant loads on them. As the configuration of the structure may affect the loading behaviour, investigation of shipping water loads in different structural conditions is required. This paper presents a numerical investigation of the effect of deck roughness and deck length on vertical and horizontal loads caused by shipping water on a fixed structure. Systematic analyses were carried out of isolated shipping water events generated with the wet dam-break method and simulated with OpenFoam Computational Fluid Dynamics toolbox. The numerical approach was validated and then the shipping water loads were examined. It was found that, as roughness increased, the maximum vertical and horizontal loads showed a delay. As the deck length reduced, the vertical backflow loads tended to increase. These results suggest it may be worthwhile examining the behaviour of shipping water as it propagates over rough surfaces caused by fouling, corrosion, or those with small structural elements distributed on them. Moreover, the effect of deck length is important in understanding the order of magnitude of loads on structures with variable deck lengths, and those which have forward and backflow loading stages.
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Conti M, Romarowski RM, Ferrarini A, Stochino M, Auricchio F, Morganti S, Segesser LKV, Ferrari E. Patient-specific computational fluid dynamics analysis of transcatheter aortic root replacement with chimney coronary grafts. Interact Cardiovasc Thorac Surg 2021; 32:408-416. [PMID: 33351896 DOI: 10.1093/icvts/ivaa288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/16/2020] [Accepted: 10/18/2020] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES Transcatheter aortic root repair (TARR) consists of the simultaneous endovascular replacement of the aortic valve, the root and the proximal ascending aorta. The aim of the study is to set-up a computational model of TARR to explore the impact of the endovascular procedure on the coronary circulation supported by chimney grafts. METHODS Computed tomography of a patient with dilated ascending aorta was segmented to obtain a 3-dimensional representation of the proximal thoracic aorta, including aortic root and supra-aortic branches. Computed assisted design tools were used to modify the geometry to create the post-procedural TARR configuration featuring the main aortic endograft integrated with 2 chimney grafts for coronary circulation. Computational Fluid Dynamics simulations were run in both pre- and post-procedural configurations using a pulsatile inflow and lumped parameter models at the outflows to simulate peripheral aortic and coronary circulation. Differences in coronary flow and pressure along the cardiac cycle were evaluated. RESULTS After the virtual implant of the TARR device with coronary grafts, the flow became more organized and less recirculation was seen in the ascending aorta. Coronary perfusion was guaranteed with negligible flow differences between pre- and post-procedural configurations. However, despite being well perfused by chimney grafts, the procedure induces an increase of the pressure drop between the coronary ostia and the ascending aorta of 8 mmHg. CONCLUSIONS The proposed numerical simulations, in the specific case under investigation, suggest that the TARR technique maintains coronary perfusion through the chimney grafts. This study calls for experimental validation and further analyses of the impact of TARR on cardiac afterload, decrease of aortic compliance and local pressure drop induced by the coronary chimney grafts.
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Affiliation(s)
- Michele Conti
- Department of Civil Engineering and Architecture, University of Pavia, Pavia, Italy
| | - Rodrigo M Romarowski
- Department of Civil Engineering and Architecture, University of Pavia, Pavia, Italy
| | - Anna Ferrarini
- Department of Civil Engineering and Architecture, University of Pavia, Pavia, Italy
| | - Matteo Stochino
- Department of Civil Engineering and Architecture, University of Pavia, Pavia, Italy
| | - Ferdinando Auricchio
- Department of Civil Engineering and Architecture, University of Pavia, Pavia, Italy
| | - Simone Morganti
- Department of Electrical, Computer, and Biomedical Engineering, University of Pavia, Pavia, Italy
| | | | - Enrico Ferrari
- Cardiac Surgery Unit, University of Zurich, Zurich, Switzerland.,Cardiac Surgery Unit, Cardiocentro Ticino, Lugano, Switzerland
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Numerical Models Can Assist Choice of an Aortic Phantom for In Vitro Testing. Bioengineering (Basel) 2021; 8:bioengineering8080101. [PMID: 34436104 PMCID: PMC8389249 DOI: 10.3390/bioengineering8080101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/18/2021] [Accepted: 07/19/2021] [Indexed: 11/17/2022] Open
Abstract
(1) Background: The realization of appropriate aortic replicas for in vitro experiments requires a suitable choice of both the material and geometry. The matching between the grade of details of the geometry and the mechanical response of the materials is an open issue that deserves attention. (2) Methods: To explore this issue, we performed a series of Fluid–Structure Interaction simulations, which compared the dynamics of three aortic models. Specifically, we reproduced a patient-specific geometry with a wall of biological tissue or silicone, and a parametric geometry based on in vivo data made in silicone. The biological tissue and the silicone were modeled with a fiber-oriented anisotropic and isotropic hyperelastic model, respectively. (3) Results: Clearly, both the aorta’s geometry and its constitutive material contribute to the determination of the aortic arch deformation; specifically, the parametric aorta exhibits a strain field similar to the patient-specific model with biological tissue. On the contrary, the local geometry affects the flow velocity distribution quite a lot, although it plays a minor role in the helicity along the arch. (4) Conclusions: The use of a patient-specific prototype in silicone does not a priori ensure a satisfactory reproducibility of the real aorta dynamics. Furthermore, the present simulations suggest that the realization of a simplified replica with the same compliance of the real aorta is able to mimic the overall behavior of the vessel.
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Transcatheter Heart Valve Implantation in Bicuspid Patients with Self-Expanding Device. Bioengineering (Basel) 2021; 8:bioengineering8070091. [PMID: 34356198 PMCID: PMC8301021 DOI: 10.3390/bioengineering8070091] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/22/2021] [Accepted: 06/22/2021] [Indexed: 11/30/2022] Open
Abstract
Bicuspid aortic valve (BAV) patients are conventionally not treated by transcathether aortic valve implantation (TAVI) because of anatomic constraint with unfavorable outcome. Patient-specific numerical simulation of TAVI in BAV may predict important clinical insights to assess the conformability of the transcathether heart valves (THV) implanted on the aortic root of members of this challenging patient population. We aimed to develop a computational approach and virtually simulate TAVI in a group of n.6 stenotic BAV patients using the self-expanding Evolut Pro THV. Specifically, the structural mechanics were evaluated by a finite-element model to estimate the deformed THV configuration in the oval bicuspid anatomy. Then, a fluid–solid interaction analysis based on the smoothed-particle hydrodynamics (SPH) technique was adopted to quantify the blood-flow patterns as well as the regions at high risk of paravalvular leakage (PVL). Simulations demonstrated a slight asymmetric and elliptical expansion of the THV stent frame in the BAV anatomy. The contact pressure between the luminal aortic root surface and the THV stent frame was determined to quantify the device anchoring force at the level of the aortic annulus and mid-ascending aorta. At late diastole, PVL was found in the gap between the aortic wall and THV stent frame. Though the modeling framework was not validated by clinical data, this study could be considered a further step towards the use of numerical simulations for the assessment of TAVI in BAV, aiming at understanding patients not suitable for device implantation on an anatomic basis.
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Nannini G, Caimi A, Palumbo MC, Saitta S, Girardi LN, Gaudino M, Roman MJ, Weinsaft JW, Redaelli A. Aortic hemodynamics assessment prior and after valve sparing reconstruction: A patient-specific 4D flow-based FSI model. Comput Biol Med 2021; 135:104581. [PMID: 34174756 DOI: 10.1016/j.compbiomed.2021.104581] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 06/09/2021] [Accepted: 06/13/2021] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Valve-sparing root replacement (VSRR) of the ascending aorta is a life-saving procedure for the treatment of aortic aneurysms, but patients remain at risk for post-operative events involving the downstream native aorta, the mechanism for which is uncertain. It is possible that proximal graft replacement of the ascending aorta induces hemodynamics alterations in the descending aorta, which could trigger adverse events. Herein, we present a fluid-structure interaction (FSI) protocol, based on patient-specific geometry and boundary conditions, to assess impact of proximal aortic grafts on downstream aortic hemodynamics and distensibility. METHODS Cardiac magnetic resonance (CMR), including MRA, cine-CMR and 4D flow sequences, was performed prior and after VSRR on one subject. Central blood pressure was non-invasively acquired at the time of the CMR: data were used to reconstruct the pre- and post-VSRR model and derive patient-specific boundary conditions for the FSI and a computational fluid dynamic (CFD) analysis with the same settings. Results were validated comparing the predicted velocity field against 4D flow dataset, over four landmarks along the aorta, and the predicted distensibility against the cine-CMR derived value. RESULTS Instantaneous velocity magnitudes extracted from 4D flow and FSI were similar (p > 0.05), while CFD-predicted velocity was significantly higher (p < 0.001), especially in the descending aorta of the pre-VSRR model (vmax was 73 cm/s, 76 cm/s and 99 cm/s, respectively). As measured in cine-CMR, FSI predicted an increase in descending aorta distensibility after grafting (i.e., 4.02 to 5.79 10-3 mmHg-1). In the descending aorta, the post-VSRR model showed increased velocity, aortic distensibility, stress and strain and wall shear stress. CONCLUSIONS Our Results indicate that i) the distensibility of the wall cannot be neglected, and hence the FSI method is necessary to obtain reliable results; ii) graft implantation induces alterations in the hemodynamics and biomechanics along the thoracic aorta, that may trigger adverse vessel remodeling.
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Affiliation(s)
- Guido Nannini
- Department of Electronics Information and Bioengineering, Politecnico di Milano, Milan, Italy.
| | - Alessandro Caimi
- Department of Electronics Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Maria Chiara Palumbo
- Department of Electronics Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Simone Saitta
- Department of Electronics Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Leonard N Girardi
- Department of Cardiothoracic Surgery, Weill Cornell Medicine, New York, NY, USA
| | - Mario Gaudino
- Department of Cardiothoracic Surgery, Weill Cornell Medicine, New York, NY, USA
| | - Mary J Roman
- Department of Medicine (Cardiology), Weill Cornell College, New York, NY, USA
| | - Jonathan W Weinsaft
- Department of Medicine (Cardiology), Weill Cornell College, New York, NY, USA
| | - Alberto Redaelli
- Department of Electronics Information and Bioengineering, Politecnico di Milano, Milan, Italy
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Multiphase Phase-Field Lattice Boltzmann Method for Simulation of Soluble Surfactants. Symmetry (Basel) 2021. [DOI: 10.3390/sym13061019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This paper proposes a phase-field model for the lattice Boltzmann method which has discretized symmetrical directions of velocities in a cartesian grid, to simulate the soluble surfactant in a Multicomponent multiphase system. Despite other existing phase-field models following Langmuir relation, the interfacial tension can be calculated analytically in this proposed model. Parameters playing roles in the models and controlling the surfactant’s strength and interaction with other phases are obtained directly from a given initial interfacial tension and bulk surfactant. Consequently, there is no further need for trial-and-error simulations, and a real system, e.g., oil-water-surfactant, can be simulated with given initial parameters. The model is validated with the analytical result for a planar oil–water-surfactant system. Furthermore, the method for reobtaining numerical interfacial tension for five different cases is tested and compared with the given initial values for an oil droplet surrounded by water and surfactant. The results show that the obtained interfacial tension from the method is in good agreement with the given initial interfacial tension. Furthermore, the spurious velocity of the model is calculated and seen that the magnitude of spurious velocities is proportional to interfacial tension.
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Cutugno S, Ingrassia T, Nigrelli V, Pasta S. On the Left Ventricular Remodeling of Patients with Stenotic Aortic Valve: A Statistical Shape Analysis. Bioengineering (Basel) 2021; 8:66. [PMID: 34068270 PMCID: PMC8153107 DOI: 10.3390/bioengineering8050066] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/27/2021] [Accepted: 05/12/2021] [Indexed: 12/04/2022] Open
Abstract
The left ventricle (LV) constantly changes its shape and function as a response to pathological conditions, and this process is known as remodeling. In the presence of aortic stenosis (AS), the degenerative process is not limited to the aortic valve but also involves the remodeling of LV. Statistical shape analysis (SSA) offers a powerful tool for the visualization and quantification of the geometrical and functional patterns of any anatomic changes. In this paper, a SSA method was developed to determine shape descriptors of the LV under different degrees of AS and thus to shed light on the mechanistic link between shape and function. A total of n=86 patients underwent computed tomography (CT) for the evaluation of valvulopathy were segmented to obtain the LV surface and then were automatically aligned to a reference template by rigid registrations and transformations. Shape modes of the anatomical LV variation induced by the degree of AS were assessed by principal component analysis (PCA). The first shape mode represented nearly 50% of the total variance of LV shape in our patient population and was mainly associated to a spherical LV geometry. At Pearson's analysis, the first shape mode was positively correlated to both the end-diastolic volume (p<0.01, R=0.814) and end-systolic volume (p<0.01, and R=0.922), suggesting LV impairment in patients with severe AS. A predictive model built with PCA-related shape modes achieved better performance in stratifying the occurrence of adverse events with respect to a baseline model using clinical demographic data as risk predictors. This study demonstrated the potential of SSA approaches to detect the association of complex 3D shape features with functional LV parameters.
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Affiliation(s)
| | - Tommaso Ingrassia
- Dipartimento di Ingegneria (DING), Università degli Studi di Palermo, Viale delle Scienze Ed.8, 90128 Palermo, Italy; (S.C.); (V.N.); (S.P.)
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Ngo MT, Lee UY, Ha H, Jin N, Chung GH, Kwak YG, Jung J, Kwak HS. Comparison of Hemodynamic Visualization in Cerebral Arteries: Can Magnetic Resonance Imaging Replace Computational Fluid Dynamics? J Pers Med 2021; 11:jpm11040253. [PMID: 33808514 PMCID: PMC8066205 DOI: 10.3390/jpm11040253] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/23/2021] [Accepted: 03/27/2021] [Indexed: 01/04/2023] Open
Abstract
A multimodality approach was applied using four-dimensional flow magnetic resonance imaging (4D flow MRI), time-of-flight magnetic resonance angiography (TOF-MRA) signal intensity gradient (SIG), and computational fluid dynamics (CFD) to investigate the 3D blood flow characteristics and wall shear stress (WSS) of the cerebral arteries. TOF-MRA and 4D flow MRI were performed on the major cerebral arteries in 16 healthy volunteers (mean age 34.7 ± 7.6 years). The flow rate measured with 4D flow MRI in the internal carotid artery, middle cerebral artery, and anterior cerebral artery were 3.8, 2.5, and 1.2 mL/s, respectively. The 3D blood flow pattern obtained through CFD and 4D flow MRI on the cerebral arteries showed reasonable consensus. CFD delivered much greater resolution than 4D flow MRI. TOF-MRA SIG and CFD WSS of the major cerebral arteries showed reasonable consensus with the locations where the WSS was relatively high. However, the visualizations were very different between TOF-MRA SIG and CFD WSS at the internal carotid artery bifurcations, the anterior cerebral arteries, and the anterior communicating arteries. 4D flow MRI, TOF-MRA SIG, and CFD are complementary methods that can provide additional insight into the hemodynamics of the human cerebral artery.
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Affiliation(s)
- Minh Tri Ngo
- Department of Radiology and Research Institute of Clinical Medicine of Jeonbuk National University, Biomedical Research Institute of Jeonbuk National University Hospital, Jeon-ju 54907, Korea; (M.T.N.); (G.H.C.); (Y.G.K.)
| | - Ui Yun Lee
- Division of Mechanical Design Engineering, Jeonbuk National University, Jeon-ju 54896, Korea;
| | - Hojin Ha
- Department of Mechanical and Biomedical Engineering, Kangwon National University, Chuncheon 24341, Korea;
| | - Ning Jin
- Siemens Medical Solutions USA, Inc., Chicago, IL 60089, USA;
| | - Gyung Ho Chung
- Department of Radiology and Research Institute of Clinical Medicine of Jeonbuk National University, Biomedical Research Institute of Jeonbuk National University Hospital, Jeon-ju 54907, Korea; (M.T.N.); (G.H.C.); (Y.G.K.)
| | - Yeong Gon Kwak
- Department of Radiology and Research Institute of Clinical Medicine of Jeonbuk National University, Biomedical Research Institute of Jeonbuk National University Hospital, Jeon-ju 54907, Korea; (M.T.N.); (G.H.C.); (Y.G.K.)
| | - Jinmu Jung
- Division of Mechanical Design Engineering, Jeonbuk National University, Jeon-ju 54896, Korea;
- Hemorheology Research Institute, Jeonbuk National University, Jeon-ju 54896, Korea
- Correspondence: (J.J.); (H.S.K.); Tel.: +82-63-270-3998 (J.J.); +82-63-250-2582 (H.S.K.)
| | - Hyo Sung Kwak
- Department of Radiology and Research Institute of Clinical Medicine of Jeonbuk National University, Biomedical Research Institute of Jeonbuk National University Hospital, Jeon-ju 54907, Korea; (M.T.N.); (G.H.C.); (Y.G.K.)
- Correspondence: (J.J.); (H.S.K.); Tel.: +82-63-270-3998 (J.J.); +82-63-250-2582 (H.S.K.)
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Li D, Zheng T, Liu Z, Li Y, Yuan D, Fan Y. Influence of Distal Re-entry Tears on False Lumen Thrombosis After Thoracic Endovascular Aortic Repair in Type B Aortic Dissection Patients: A Computational Fluid Dynamics Simulation. Cardiovasc Eng Technol 2021; 12:426-437. [PMID: 33768445 DOI: 10.1007/s13239-021-00532-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 03/05/2021] [Indexed: 02/05/2023]
Abstract
PURPOSE Distal re-entry tears play a significant role in false lumen (FL) thrombosis, which will strongly affect the postoperative long-term survival of patients with type B aortic dissection (TBAD) after thoracic endovascular aortic repair (TEVAR). This study aimed to investigate the influence of a peculiar morphological parameter of the residual re-entry tears in TBAD patients after TEVAR on long-term FL thrombosis using the computational fluid dynamics. METHODS Ideal population-based three-dimensional models of post-operative TBAD were established. Numerical simulation was performed to investigate the hemodynamic differences caused by different tear features, including the tear count, the maximum distance between tears, and the tear area. RESULTS Although the low relative residence time (RRT) area did not change significantly when the tear distance was fixed, the area of oscillatory shear index (OSI) > 0.45 and endothelial cell activation potential (ECAP) > 1.5 decreased significantly with the tear count and area increased and a dramatic increase in blood flow into the FL was also observed. When tear count and total area were fixed, for each 10-mm increase in the maximum distance between tears, the area of low RRT in the FL increased significantly, while the average pressure difference increased by 10.85%. CONCLUSION The different morphology of the re-entry tears had different effects on the thrombosis-related hemodynamic parameters in FL following TEVAR. and the number of re-entry tears was most crucial to the potential thrombosis in the post-TEVAR FL of TBAD patients.
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Affiliation(s)
- Da Li
- Department of Applied Mechanics, Sichuan University, Chengdu, 610065, China
| | - Tinghui Zheng
- Department of Applied Mechanics, Sichuan University, Chengdu, 610065, China
| | - Zhan Liu
- Department of Applied Mechanics, Sichuan University, Chengdu, 610065, China
| | - Yan Li
- Department of Applied Mechanics, Sichuan University, Chengdu, 610065, China
| | - Ding Yuan
- Department Vascular Surgery of West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu, 610041, China.
| | - Yubo Fan
- Beijing Advanced Innovation Center of Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191, China.
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Di Giuseppe M, Farzaneh S, Zingales M, Pasta S, Avril S. Patient-specific computational evaluation of stiffness distribution in ascending thoracic aortic aneurysm. J Biomech 2021; 119:110321. [PMID: 33662747 DOI: 10.1016/j.jbiomech.2021.110321] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/21/2021] [Accepted: 02/03/2021] [Indexed: 12/21/2022]
Abstract
Quantifying local aortic stiffness properties in vivo is acknowledged as essential to assess the severity of an ascending thoracic aortic aneurysm (ATAA). Recently, the LESI (local extensional stiffness identification) methodology has been established to quantify non-invasively local stiffness properties of ATAAs using electrocardiographic-gated computed tomography (ECG-gated CT) scans. The aim of the current study was to determine the most sensitive markers of local ATAA stiffness estimation with the hypothesis that direct measures of local ATAA stiffness could better detect the high-risk patients. A cohort of 30 patients (12 BAV and 18 TAV) referred for aortic size evaluation by ECG-gated CT were recruited. For each patient, the extensional stiffness Q was evaluated by the LESI methodology whilst computational flow analyses were also performed to derive hemodynamics markers such as the wall shear stress (WSS). A strong positive correlation was found between the extensional stiffness and the aortic pulse pressure (R = 0.644 and p < 0.001). Interestingly, a significant positive correlation was also found between the extensional stiffness and patients age for BAV ATAAs (R = 0.619 and p = 0.032), but not for TAV ATAAs (R = -0.117 and p = 0.645). No significant correlation was found between the extensional stiffness and WSS evaluated locally. There was no significant difference either in the extensional stiffness between BAV ATAAs and TAV ATAAs (Q = 3.6 ± 2.5 MPa.mm for BAV ATAAs vs Q = 5.3 ± 3.1 MPa.mm for TAV ATAAs, p = 0.094). Future work will focus on relating the extensional stiffness to the patient-specific rupture risk of ATAAs on larger cohorts to confirm the promising interest of the LESI methodology.
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Affiliation(s)
- Marzio Di Giuseppe
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties, University of Palermo, 90128 Palermo, Italy
| | - Solmaz Farzaneh
- Mines Saint-Etienne, Univ Lyon, Univ Jean Monnet, INSERM, U1059 SAINBIOSE, Saint-Étienne 42023, France
| | - Massimiliano Zingales
- Department of Engineering, Viale delle Scienze, Ed.8, University of Palermo, 90128 Palermo, Italy
| | - Salvatore Pasta
- Department of Engineering, Viale delle Scienze, Ed.8, University of Palermo, 90128 Palermo, Italy
| | - Stéphane Avril
- Mines Saint-Etienne, Univ Lyon, Univ Jean Monnet, INSERM, U1059 SAINBIOSE, Saint-Étienne 42023, France.
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Ibanez I, de Azevedo Gomes BA, Nieckele AO. Effect of percutaneous aortic valve position on stress map in ascending aorta: A fluid-structure interaction analysis. Artif Organs 2021; 45:O195-O206. [PMID: 33326639 DOI: 10.1111/aor.13883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 12/06/2020] [Accepted: 12/10/2020] [Indexed: 11/30/2022]
Abstract
Transcatheter aortic valve implantation (TAVI) is an increasingly widespread procedure. Although this intervention is indicated for high and low surgical risk patients, some issues still remain, such as prosthesis positioning optimization in the aortic annulus. Coaxial positioning of the percutaneous prosthesis influences directly on the aortic wall stress map. The determination of the mechanical stress that acts on the vascular endothelium resulting from blood flow can be considered an important task, since TAVI positioning can lead to unfavorable hemodynamic patterns, resulting in changes in parietal stress, such as those found in post-stenotic dilatation region. This research aims to investigate the influence of the prosthetic valve inclination angle in the mechanical stresses acting in the ascending aortic wall. Aortic compliance and blood flow during cardiac cycle were numerically obtained using fluid structure interaction. The aortic model was developed through segmentation of a computed tomography image of a specific patient submitted to TAVI. When compared to standard position (coaxiality match between the prosthesis and the aortic annulus), the inclination of 4° directed to the left main coronary artery decreased the aortic wall area with high values of wall shear stress and pressure. Coaxial positioning optimization of percutaneous aortic prosthesis may decrease the high mechanical stress area. These changes may be important to reduce the aortic remodeling process, vascular calcification or even the prosthesis half-life. Computational fluid dynamics makes room for personalized medicine, with manufactured prosthesis tailored to each patient.
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Affiliation(s)
- Ivan Ibanez
- Department of Mechanical Engineering, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Bruno A de Azevedo Gomes
- Department of Mechanical Engineering, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Nacional de Cardiologia - MS, Rio de Janeiro, Brazil
| | - Angela O Nieckele
- Department of Mechanical Engineering, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, Brazil
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Ascending Aorta Resection and End-to-End Anastomosis: Redistribution of Wall Shear Stress Induced by a Bioprosthetic Heart Valve. PROSTHESIS 2020. [DOI: 10.3390/prosthesis2040026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Although aortic resection and end-to-end anastomosis are applied to repair ascending aortic aneurysm, there is a lack of information on the late risk of post-operative complications, such as aortic dissection and aneurysmal re-dilatation. It is recognized that altered hemodynamic forces exerted on an aortic wall play an important role on dissection and aneurysm formation. We present a case in which the hemodynamic forces were investigated prior and after repair of an ascending aorta treated by resection with end-to-end anastomosis and a bioprosthetic heart valve. Post-operative wall shear stress was redistributed uniformly along the vessel circumference, and this may suggest a reduced risk of complications near aortic root, but not exclude the re-dilatation of the ascending aorta.
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36
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Capellini K, Gasparotti E, Cella U, Costa E, Fanni BM, Groth C, Porziani S, Biancolini ME, Celi S. A novel formulation for the study of the ascending aortic fluid dynamics with in vivo data. Med Eng Phys 2020; 91:68-78. [PMID: 33008714 DOI: 10.1016/j.medengphy.2020.09.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 08/20/2020] [Accepted: 09/12/2020] [Indexed: 01/18/2023]
Abstract
Numerical simulations to evaluate thoracic aortic hemodynamics include a computational fluid dynamic (CFD) approach or fluid-structure interaction (FSI) approach. While CFD neglects the arterial deformation along the cardiac cycle by applying a rigid wall simplification, on the other side the FSI simulation requires a lot of assumptions for the material properties definition and high computational costs. The aim of this study is to investigate the feasibility of a new strategy, based on Radial Basis Functions (RBF) mesh morphing technique and transient simulations, able to introduce the patient-specific changes in aortic geometry during the cardiac cycle. Starting from medical images, aorta models at different phases of cardiac cycle were reconstructed and a transient shape deformation was obtained by proper activating incremental RBF solutions during the simulation process. The results, in terms of main hemodynamic parameters, were compared with two performed CFD simulations for the aortic model at minimum and maximum volume. Our implemented strategy copes the actual arterial variation during cardiac cycle with high accuracy, capturing the impact of geometrical variations on fluid dynamics, overcoming the complexity of a standard FSI approach.
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Affiliation(s)
- Katia Capellini
- BioCardioLab, Fondazione Toscana Gabriele Monasterio, Massa, Italy; Department of Information Engineering, University of Pisa, Pisa, Italy
| | - Emanuele Gasparotti
- BioCardioLab, Fondazione Toscana Gabriele Monasterio, Massa, Italy; Department of Information Engineering, University of Pisa, Pisa, Italy
| | - Ubaldo Cella
- Department of Enterprise Engineering, University of Rome Tor Vergata, Rome, Italy
| | | | - Benigno Marco Fanni
- BioCardioLab, Fondazione Toscana Gabriele Monasterio, Massa, Italy; Department of Information Engineering, University of Pisa, Pisa, Italy
| | - Corrado Groth
- Department of Enterprise Engineering, University of Rome Tor Vergata, Rome, Italy
| | - Stefano Porziani
- Department of Enterprise Engineering, University of Rome Tor Vergata, Rome, Italy
| | | | - Simona Celi
- BioCardioLab, Fondazione Toscana Gabriele Monasterio, Massa, Italy.
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37
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Deciphering ascending thoracic aortic aneurysm hemodynamics in relation to biomechanical properties. Med Eng Phys 2020; 82:119-129. [DOI: 10.1016/j.medengphy.2020.07.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/19/2020] [Accepted: 07/09/2020] [Indexed: 12/20/2022]
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Lipp SN, Niedert EE, Cebull HL, Diorio TC, Ma JL, Rothenberger SM, Stevens Boster KA, Goergen CJ. Computational Hemodynamic Modeling of Arterial Aneurysms: A Mini-Review. Front Physiol 2020; 11:454. [PMID: 32477163 PMCID: PMC7235429 DOI: 10.3389/fphys.2020.00454] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 04/09/2020] [Indexed: 01/02/2023] Open
Abstract
Arterial aneurysms are pathological dilations of blood vessels, which can be of clinical concern due to thrombosis, dissection, or rupture. Aneurysms can form throughout the arterial system, including intracranial, thoracic, abdominal, visceral, peripheral, or coronary arteries. Currently, aneurysm diameter and expansion rates are the most commonly used metrics to assess rupture risk. Surgical or endovascular interventions are clinical treatment options, but are invasive and associated with risk for the patient. For aneurysms in locations where thrombosis is the primary concern, diameter is also used to determine the level of therapeutic anticoagulation, a treatment that increases the possibility of internal bleeding. Since simple diameter is often insufficient to reliably determine rupture and thrombosis risk, computational hemodynamic simulations are being developed to help assess when an intervention is warranted. Created from subject-specific data, computational models have the potential to be used to predict growth, dissection, rupture, and thrombus-formation risk based on hemodynamic parameters, including wall shear stress, oscillatory shear index, residence time, and anomalous blood flow patterns. Generally, endothelial damage and flow stagnation within aneurysms can lead to coagulation, inflammation, and the release of proteases, which alter extracellular matrix composition, increasing risk of rupture. In this review, we highlight recent work that investigates aneurysm geometry, model parameter assumptions, and other specific considerations that influence computational aneurysm simulations. By highlighting modeling validation and verification approaches, we hope to inspire future computational efforts aimed at improving our understanding of aneurysm pathology and treatment risk stratification.
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Affiliation(s)
- Sarah N. Lipp
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Elizabeth E. Niedert
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Hannah L. Cebull
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Tyler C. Diorio
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Jessica L. Ma
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Sean M. Rothenberger
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Kimberly A. Stevens Boster
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, United States
| | - Craig J. Goergen
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
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Fluid Structure Interaction on Paravalvular Leakage of Transcatheter Aortic Valve Implantation Related to Aortic Stenosis: A Patient-Specific Case. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2020; 2020:9163085. [PMID: 32454886 PMCID: PMC7219000 DOI: 10.1155/2020/9163085] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 01/25/2020] [Accepted: 01/30/2020] [Indexed: 01/14/2023]
Abstract
This study investigated the impact of paravalvular leakage (PVL) in relation to the different valve openings of the transcatheter aortic valve implantation (TAVI) valve using the fluid structure interaction (FSI) approach. Limited studies were found on the subject of FSI with regards to TAVI-PVL condition, which involves both fluid and structural responses in coupling interaction. Hence, further FSI simulation with the two-way coupling method is implemented to investigate the effects of hemodynamics blood flow along the patient-specific aorta model subjected to the interrelationship between PVL and the different valve openings using the established FSI software ANSYS 16.1. A 3D patient-specific aorta model is constructed using MIMICS software. The TAVI valve identical to Edward SAPIEN XT 26 (Edwards Lifesciences, Irvine, California), at different Geometrical Orifice Areas (GOAs), is implanted into the patient's aortic annulus. The leaflet opening of the TAVI valve is drawn according to severity of GOA opening represented in terms of 100%, 80%, 60%, and 40% opening, respectively. The result proved that the smallest percentage of GOA opening produced the highest possibility of PVL, increased the recirculatory flow proximally to the inner wall of the ascending aorta, and produced lower backflow velocity streamlines through the side area of PVL region. Overall, 40% GOA produced 89.17% increment of maximum velocity magnitude, 19.97% of pressure drop, 65.70% of maximum WSS magnitude, and a decrement of 33.62% total displacement magnitude with respect to the 100% GOA.
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40
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Hirschhorn M, Tchantchaleishvili V, Stevens R, Rossano J, Throckmorton A. Fluid–structure interaction modeling in cardiovascular medicine – A systematic review 2017–2019. Med Eng Phys 2020; 78:1-13. [DOI: 10.1016/j.medengphy.2020.01.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 01/18/2020] [Accepted: 01/26/2020] [Indexed: 01/06/2023]
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OLIVEIRA DIANAC, LARANJO SÉRGIO, TIAGO JORGE, PINTO FÁTIMAF, SEQUEIRA ADÉLIA. NUMERICAL SIMULATION OF DILATION PATTERNS OF THE ASCENDING AORTA IN AORTOPATHIES. J MECH MED BIOL 2020. [DOI: 10.1142/s0219519419500684] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Aortic dilation is associated with congenital bicuspid aortic valve (BAV) disease, and its etiology is still not completely understood. The aim of this study is to provide further insight into aortic hemodynamics in a BAV population with different degrees of aortic dilation and regurgitation in comparison with a patient without pathology. A fluid–structure interaction (FSI) numerical approach is implemented regarding patient-specific geometries, where the aortic valves are defined by analytical orifices. Results show that, while the patient without pathology displays a typical hemodynamic behavior of flows in bends, BAV-related aortas present an accelerated flow along the outer aortic wall. Wall shear stress (WSS) overload in the outer curvature is observed, more marked in more dilated aortas. Moreover, helices in the ascending aorta are present in these patients, enhanced with greater dilation. These findings support the fact that hemodynamic factors play an important role in aortic dilation onset and development in BAV patients, caused by a prolonged exposure of the outer ascending aortic curvature to altered WSS. Besides, our results suggest that greater aortic regurgitation may be associated with abnormal WSS distributions in the ascending aorta during diastole, which can facilitate aortic root dilation.
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Affiliation(s)
- DIANA C. OLIVEIRA
- Department of Bioengineering and CEMAT, Instituto Superior Técnico, Ulisboa Av. Rovisco Pais, 1 1049-001 Lisboa, Portugal
| | - SÉRGIO LARANJO
- Pediatric Cardiology Department, Congenital Heart Diseases Reference Centre, Hospital de Santa Marta (CHLC), Rua de Santa Marta 50 1169-024 Lisboa, Portugal
| | - JORGE TIAGO
- Department of Mathematics and CEMAT, Instituto Superior Técnico, Ulisboa Av. Rovisco Pais, 1 1049-001 Lisboa, Portugal
| | - FÁTIMA F. PINTO
- Pediatric Cardiology Department, Congenital Heart Diseases Reference Centre, Hospital de Santa Marta (CHLC), Rua de Santa Marta 50 1169-024 Lisboa, Portugal
| | - ADÉLIA SEQUEIRA
- Department of Mathematics and CEMAT, Instituto Superior Técnico, Ulisboa Av. Rovisco Pais, 1 1049-001 Lisboa, Portugal
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42
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Gao B, Zhang Q, Chang Y. Hemodynamic effects of support modes of LVADs on the aortic valve. Med Biol Eng Comput 2019; 57:2657-2671. [PMID: 31707689 DOI: 10.1007/s11517-019-02058-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 11/02/2019] [Indexed: 12/11/2022]
Abstract
As the alternative treatment for heart failure, left ventricular assist devices (LVADs) have been widely applied to clinical practice. However, the effects of the support modes of LVADs on the biomechanical states of the aortic valve are still poorly understood. Hence, the present study investigates such effects and proposes a novel fluid-structure interaction (FSI) approach that combines the lattice Boltzmann method (LBM) and finite element (FE) method. Two support modes of LVADs, namely constant speed mode and constant flow mode, which have been widely applied to clinical practice, are also designed. Results demonstrate that the support modes of LVADs could significantly affect the biomechanical states of the aortic valve and the blood flow pattern of the ascending aorta. Compared with those in the constant flow mode, the leaflets in the constant speed mode could achieve better dynamic performance and lower stress during the systolic phase. The max radial displacement of the leaflets in the constant speed mode is at 8 mm, whereas that in the constant flow mode is at 0.8 mm. Furthermore, the outflow of LVADs directly impacts the aortic surfaces of the leaflets during the diastolic phase by increasing the level of wall shear stress of the leaflets. The leaflets in the constant speed mode receive less impact than those in the constant flow mode. The condition with such minimal impact is conducive to maintaining the normal structure of leaflets and benefits the reduction of the risk of valvular diseases. In sum, the support modes of LVADs exert a crucial effect on the biomechanical environment of the aortic valve. The constant speed mode is better than the constant flow mode in terms of providing a good hemodynamic environment for the aortic valve.
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Affiliation(s)
- Bin Gao
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing, 100124, People's Republic of China.
| | - Qi Zhang
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing, 100124, People's Republic of China
| | - Yu Chang
- School of Life Science and BioEngineering, Beijing University of Technology, Beijing, 100124, People's Republic of China
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Cosentino F, Agnese V, Raffa GM, Gentile G, Bellavia D, Zingales M, Pilato M, Pasta S. On the role of material properties in ascending thoracic aortic aneurysms. Comput Biol Med 2019; 109:70-78. [DOI: 10.1016/j.compbiomed.2019.04.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/20/2019] [Accepted: 04/20/2019] [Indexed: 12/31/2022]
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Oliveira D, Rosa SA, Tiago J, Ferreira RC, Agapito AF, Sequeira A. Bicuspid aortic valve aortopathies: An hemodynamics characterization in dilated aortas. Comput Methods Biomech Biomed Engin 2019; 22:815-826. [PMID: 30957542 DOI: 10.1080/10255842.2019.1597860] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Bicuspid aortic valve (BAV) aortopathy remains of difficult clinical management due to its heterogeneity and further assessment of related aortic hemodynamics is necessary. The aim of this study was to assess systolic hemodynamic indexes and wall stresses in patients with diverse BAV phenotypes and dilated ascending aortas. The aortic geometry was reconstructed from patient-specific images while the aortic valve was generated based on patient-specific measurements. Physiologic material properties and boundary conditions were applied and fully coupled fluid-structure interaction (FSI) analysis were conducted. Our dilated aortic models were characterized by the presence of abnormal hemodynamics with elevated degrees of flow skewness and eccentricity, regardless of BAV morphotype. Retrograde flow was also present. Both features, predicted by flow angle and flow reversal ratios, were consistently higher than those reported for non-dilated aortas. Right-handed helical flow was present, as well as elevated wall shear stress (WSS) on the outer ascending aortic wall. Our results suggest that the abnormal flow associated with BAV may play a role in aortic enlargement and progress it further on already dilated aortas.
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Affiliation(s)
- Diana Oliveira
- a Department of Mathematics and CEMAT , Instituto Superior Técnico, University of Lisbon , Lisbon , Portugal
| | - Sílvia Aguiar Rosa
- b Cardiology Department , Hospital de Santa Marta (CHLC) , Lisboa , Portugal
| | - Jorge Tiago
- a Department of Mathematics and CEMAT , Instituto Superior Técnico, University of Lisbon , Lisbon , Portugal
| | - Rui Cruz Ferreira
- b Cardiology Department , Hospital de Santa Marta (CHLC) , Lisboa , Portugal
| | | | - Adélia Sequeira
- a Department of Mathematics and CEMAT , Instituto Superior Técnico, University of Lisbon , Lisbon , Portugal
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