1
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Mei J, Yuan Y, Yan H, Zhao X, Xue T, Su H, Jia Z. Factors associated with false lumen changes in patients with superior mesenteric artery dissection. Vasc Med 2024:1358863X231220624. [PMID: 38334057 DOI: 10.1177/1358863x231220624] [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: 02/10/2024]
Abstract
BACKGROUND False lumen changes (FLCs) are the main reference for the prognosis judgment and treatment plan selection for type IIa superior mesenteric artery dissection (SMAD). METHODS For this retrospective study, 55 patients with symptomatic type IIa SMAD were included. Computational fluid dynamics (CFD) analysis was used to explore the hemodynamic basis of FLCs. Correlation and multiple linear regression analyses were performed to identify clinical, morphological and hemodynamic factors associated with FLCs. RESULTS The FLCs of patients with successful conservative treatment (n = 29) are significantly higher than those with failed conservative treatment (n = 26) (58.5 ± 21.1% vs 10.9 ± 17.4%, p < 0.0001). Positive correlations were seen between FLCs and the morphological parameters false lumen length (FLL)/dissection entrance length (DEL) and FLL. In terms of hemodynamic parameters, negative correlations were seen between FLCs and time-averaged wall shear stress (TAWSS), vorticity, and high areas of TAWSS and vorticity, whereas positive correlations were seen between FLCs and oscillatory shear index (OSI), relative residence time (RRT), and high areas of OSI and RRT. Multiple linear regression analysis identified symptom duration (odds ratio [OR], 0.93; 95% CI, 0.91-0.96; p < 0.0001), FLL/DEL (OR, 1.30; 95% CI, 1.01-1.67; p = 0.044), and high RRT area (OR, 2.03; 95% CI, 1.48-2.78; p < 0.0001) as predictors of FLCs. CONCLUSION The clinical predictor symptom duration, morphological factor FLL/DEL, and the hemodynamic factor high RRT area can serve as predictors of FLCs in patients with symptomatic type IIa SMAD.
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Affiliation(s)
- Junhao Mei
- Department of Interventional and Vascular Surgery, The Affiliated Changzhou Second People's Hospital of Nanjing Medical University, Changzhou, China
| | - Yuan Yuan
- Department of Interventional Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Hui Yan
- Department of Radiology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Xi Zhao
- Central Research Institute, United Imaging Healthcare, Shanghai, China
| | - Tongqing Xue
- Department of Interventional Radiology, Huaian Hospital of Huaian's City, Huai'an, China
| | - Haobo Su
- Department of Interventional Radiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Zhongzhi Jia
- Department of Interventional and Vascular Surgery, The Affiliated Changzhou Second People's Hospital of Nanjing Medical University, Changzhou, China
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2
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Sarantides P, Raptis A, Mathioulakis D, Moulakakis K, Kakisis J, Manopoulos C. Computational Study of Abdominal Aortic Aneurysm Walls Accounting for Patient-Specific Non-Uniform Intraluminal Thrombus Thickness and Distinct Material Models: A Pre- and Post-Rupture Case. Bioengineering (Basel) 2024; 11:144. [PMID: 38391630 PMCID: PMC10886172 DOI: 10.3390/bioengineering11020144] [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: 11/30/2023] [Revised: 01/23/2024] [Accepted: 01/26/2024] [Indexed: 02/24/2024] Open
Abstract
An intraluminal thrombus (ILT) is present in the majority of abdominal aortic aneurysms, playing a crucial role in their growth and rupture. Although most computational studies do not include the ILT, in the present study, this is taken into account, laying out the whole simulation procedure, namely, from computed tomography scans to medical image segmentation, geometry reconstruction, mesh generation, biomaterial modeling, finite element analysis, and post-processing, all carried out in open software. By processing the tomography scans of a patient's aneurysm before and after rupture, digital twins are reconstructed assuming a uniform aortic wall thickness. The ILT and the aortic wall are assigned different biomaterial models; namely, the first is modeled as an isotropic linear elastic material, and the second is modeled as the Mooney-Rivlin hyperelastic material as well as the transversely isotropic hyperelastic Holzapfel-Gasser-Ogden nonlinear material. The implementation of the latter requires the designation of local Cartesian coordinate systems in the aortic wall, suitably oriented in space, for the proper orientation of the collagen fibers. The composite aneurysm geometries (ILT and aortic wall structures) are loaded with normal and hypertensive static intraluminal pressure. Based on the calculated stress and strain distributions, ILT seems to be protecting the aneurysm from a structural point of view, as the highest stresses appear in the thrombus-free areas of the aneurysmal wall.
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Affiliation(s)
- Platon Sarantides
- Laboratory of Biofluid Mechanics & Biomedical Technology, School of Mechanical Engineering, National Technical University of Athens, 157 72 Zografos, Greece
| | - Anastasios Raptis
- Laboratory of Biofluid Mechanics & Biomedical Technology, School of Mechanical Engineering, National Technical University of Athens, 157 72 Zografos, Greece
| | - Dimitrios Mathioulakis
- Laboratory of Biofluid Mechanics & Biomedical Technology, School of Mechanical Engineering, National Technical University of Athens, 157 72 Zografos, Greece
- School of Engineering, Bahrain Polytechnic, Isa Town P.O. Box 33349, Bahrain
| | - Konstantinos Moulakakis
- Department of Vascular Surgery, School of Medicine, University of Patras, 265 04 Patras, Greece
| | - John Kakisis
- Department of Vascular Surgery, Attikon University Hospital, National and Kapodistrian University of Athens, 106 79 Athens, Greece
| | - Christos Manopoulos
- Laboratory of Biofluid Mechanics & Biomedical Technology, School of Mechanical Engineering, National Technical University of Athens, 157 72 Zografos, Greece
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3
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Loste A, Clément M, Delbosc S, Guedj K, Sénémaud J, Gaston AT, Morvan M, Even G, Gautier G, Eggel A, Arock M, Procopio E, Deschildre C, Louedec L, Michel JB, Deschamps L, Castier Y, Coscas R, Alsac JM, Launay P, Caligiuri G, Nicoletti A, Le Borgne M. Involvement of an IgE/Mast cell/B cell amplification loop in abdominal aortic aneurysm progression. PLoS One 2023; 18:e0295408. [PMID: 38055674 DOI: 10.1371/journal.pone.0295408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 11/21/2023] [Indexed: 12/08/2023] Open
Abstract
AIMS IgE type immunoglobulins and their specific effector cells, mast cells (MCs), are associated with abdominal aortic aneurysm (AAA) progression. In parallel, immunoglobulin-producing B cells, organised in tertiary lymphoid organs (TLOs) within the aortic wall, have also been linked to aneurysmal progression. We aimed at investigating the potential role and mechanism linking local MCs, TLO B cells, and IgE production in aneurysmal progression. METHODS AND RESULTS Through histological assays conducted on human surgical samples from AAA patients, we uncovered that activated MCs were enriched at sites of unhealed haematomas, due to subclinical aortic wall fissuring, in close proximity to adventitial IgE+ TLO B cells. Remarkably, in vitro the IgEs deriving from these samples enhanced MC production of IL-4, a cytokine which favors IgE class-switching and production by B cells. Finally, the role of MCs in aneurysmal progression was further analysed in vivo in ApoE-/- mice subjected to angiotensin II infusion aneurysm model, through MC-specific depletion after the establishment of dissecting aneurysms. MC-specific depletion improved intramural haematoma healing and reduced aneurysmal progression. CONCLUSIONS Our data suggest that MC located close to aortic wall fissures are activated by adventitial TLO B cell-produced IgEs and participate to their own activation by providing support for further IgE synthesis through IL-4 production. By preventing prompt repair of aortic subclinical fissures, such a runaway MC activation loop could precipitate aneurysmal progression, suggesting that MC-targeting treatments may represent an interesting adjunctive therapy for reducing AAA progression.
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Affiliation(s)
- Alexia Loste
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
| | - Marc Clément
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
| | - Sandrine Delbosc
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
| | - Kevin Guedj
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
| | - Jean Sénémaud
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
- Department of Vascular and Thoracic Surgery, AP-HP, Bichat Hospital, Université Paris Cité, Paris, France
| | - Anh-Thu Gaston
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
| | - Marion Morvan
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
| | - Guillaume Even
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
| | - Grégory Gautier
- DHU FIRE, Paris, France
- INSERM UMRS 1149, Centre de Recherche sur l'Inflammation (CRI), Université Paris Cité, Paris, France
| | - Alexander Eggel
- Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Michel Arock
- Department of Biology and CNRS UMR8113, Ecole Normale Supérieure de Paris-Saclay, Saclay, France
| | - Emanuele Procopio
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
| | - Catherine Deschildre
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
| | - Liliane Louedec
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
| | - Jean-Baptiste Michel
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
| | - Lydia Deschamps
- Department of Pathology, AP-HP, Bichat Hospital, Université Paris Cité, Paris, France
| | - Yves Castier
- INSERM UMRS 1149, Centre de Recherche sur l'Inflammation (CRI), Université Paris Cité, Paris, France
| | - Raphaël Coscas
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- Department of Vascular Surgery, AP-HP, Ambroise Paré University Hospital, Université Paris Cité, Boulogne-Billancourt, France
| | - Jean-Marc Alsac
- Department of Vascular Surgery, AP-HP, Hôpital Européen Georges Pompidou, Université Paris Cité, Paris, France
| | - Pierre Launay
- DHU FIRE, Paris, France
- Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Giuseppina Caligiuri
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
- Department of Cardiology, AP-HP, Bichat Hospital, Université Paris Cité, Paris, France
| | - Antonino Nicoletti
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
| | - Marie Le Borgne
- Université Paris Cité and Université Sorbonne Paris Nord, INSERM, LVTS, Paris, France
- DHU FIRE, Paris, France
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4
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Bouwens E, Vanmaele A, Hoeks SE, Verhagen HJM, Fioole B, Moelker A, ten Raa S, Hussain B, Oliveira-Pinto J, Bastos Gonçalves F, Ijpma AS, Hoefer IE, van Lier F, Akkerhuis KM, Majoor-Krakauer DF, Boersma E, Kardys I. Circulating biomarkers of cardiovascular disease are related to aneurysm volume in abdominal aortic aneurysm. Vasc Med 2023; 28:433-442. [PMID: 37395286 PMCID: PMC10559648 DOI: 10.1177/1358863x231181159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
BACKGROUND Surveillance programs in abdominal aortic aneurysms (AAA) are mainly based on imaging and leave room for improvement to timely identify patients at risk for AAA growth. Many biomarkers are dysregulated in patients with AAA, which fuels interest in biomarkers as indicators of disease progression. We examined associations of 92 cardiovascular disease (CVD)-related circulating biomarkers with AAA and sac volume. METHODS In a cross-sectional analysis, we separately investigated (1) 110 watchful waiting (WW) patients (undergoing periodic surveillance imaging without planned intervention) and (2) 203 patients after endovascular aneurysm repair (EVAR). The Cardiovascular Panel III (Olink Proteomics AB, Sweden) was used to measure 92 CVD-related circulating biomarkers. We used cluster analyses to investigate protein-based subphenotypes, and linear regression to examine associations of biomarkers with AAA and sac volume on CT scans. RESULTS Cluster analyses revealed two biomarker-based subgroups in both WW and EVAR patients, with higher levels of 76 and 74 proteins, respectively, in one subgroup versus the other. In WW patients, uPA showed a borderline significant association with AAA volume. Adjusting for clinical characteristics, there was a difference of -0.092 (-0.148, -0.036) loge mL in AAA volume per SD uPA. In EVAR patients, after multivariable adjustment, four biomarkers remained significantly associated with sac volume. The mean effects on sac volume per SD difference were: LDLR: -0.128 (-0.212, -0.044), TFPI: 0.139 (0.049, 0.229), TIMP4: 0.110 (0.023, 0.197), IGFBP-2: 0.103 (0.012, 0.194). CONCLUSION LDLR, TFPI, TIMP4, and IGFBP-2 were independently associated with sac volume after EVAR. Subgroups of patients with high levels of the majority of CVD-related biomarkers emphasize the intertwined relationship between AAA and CVD.ClinicalTrials.gov Identifier: NCT03703947.
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Affiliation(s)
- Elke Bouwens
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
- Department of Vascular Surgery, Erasmus MC, Rotterdam, The Netherlands
- Department of Anesthesiology, Erasmus MC, Rotterdam, The Netherlands
| | - Alexander Vanmaele
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
- Department of Vascular Surgery, Erasmus MC, Rotterdam, The Netherlands
| | - Sanne E Hoeks
- Department of Anesthesiology, Erasmus MC, Rotterdam, The Netherlands
| | - Hence JM Verhagen
- Department of Vascular Surgery, Erasmus MC, Rotterdam, The Netherlands
| | - Bram Fioole
- Department of Vascular Surgery, Maasstad Hospital, Rotterdam, The Netherlands
| | - Adriaan Moelker
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Sander ten Raa
- Department of Vascular Surgery, Erasmus MC, Rotterdam, The Netherlands
| | - Burhan Hussain
- Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
- Department of Radiology, Beatrix Hospital, Gorinchem, The Netherlands
| | - José Oliveira-Pinto
- Department of Vascular Surgery, Erasmus MC, Rotterdam, The Netherlands
- Department of Angiology and Vascular Surgery, Centro Hospitalar São João, Porto, Portugal
- Department of Surgery and Physiology, Faculty of Medicine of Oporto, Porto, Portugal
| | - Frederico Bastos Gonçalves
- Department of Vascular Surgery, Erasmus MC, Rotterdam, The Netherlands
- NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal
- Department of Angiology and Vascular Surgery, Hospital de Santa Marta, Centro Hospitalar Universitário de Lisboa Central, Lisbon, Portugal
| | - Arne S Ijpma
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Imo E Hoefer
- Central Diagnostic Laboratory, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Felix van Lier
- Department of Anesthesiology, Erasmus MC, Rotterdam, The Netherlands
| | | | | | - Eric Boersma
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
| | - Isabella Kardys
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
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5
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Arslan AC, Salman HE. Effect of Intraluminal Thrombus Burden on the Risk of Abdominal Aortic Aneurysm Rupture. J Cardiovasc Dev Dis 2023; 10:233. [PMID: 37367398 DOI: 10.3390/jcdd10060233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 05/19/2023] [Accepted: 05/23/2023] [Indexed: 06/28/2023] Open
Abstract
Abdominal aortic aneurysm (AAA) is a critical health disorder, where the abdominal aorta dilates more than 50% of its normal diameter. Enlargement in abdominal aorta alters the hemodynamics and flow-induced forces on the AAA wall. Depending on the flow conditions, the hemodynamic forces on the wall may result in excessive mechanical stresses that lead to AAA rupture. The risk of rupture can be predicted using advanced computational techniques such as computational fluid dynamics (CFD) and fluid-structure interaction (FSI). For a reliable rupture risk assessment, formation of intraluminal thrombus (ILT) and uncertainty in arterial material properties should be taken into account, mainly due to the patient-specific differences and unknowns in AAAs. In this study, AAA models are computationally investigated by performing CFD simulations combined with FSI analysis. Various levels of ILT burdens are artificially generated in a realistic AAA geometry, and the peak effective stresses are evaluated to elucidate the effect of material models and ILT formation. The results indicate that increasing the ILT burden leads to lowered effective stresses on the AAA wall. The material properties of the artery and ILT are also effective on the stresses; however, these effects are limited compared to the effect of ILT volume in the AAA sac.
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Affiliation(s)
- Aykut Can Arslan
- Department of Mechanical Engineering, TOBB University of Economics and Technology, Ankara 06530, Turkey
| | - Huseyin Enes Salman
- Department of Mechanical Engineering, TOBB University of Economics and Technology, Ankara 06530, Turkey
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6
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Pham J, Wyetzner S, Pfaller MR, Parker DW, James DL, Marsden AL. svMorph: Interactive Geometry-Editing Tools for Virtual Patient-Specific Vascular Anatomies. J Biomech Eng 2023; 145:031001. [PMID: 36282508 PMCID: PMC9791670 DOI: 10.1115/1.4056055] [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: 05/06/2022] [Revised: 08/07/2022] [Indexed: 12/30/2022]
Abstract
We propose svMorph, a framework for interactive virtual sculpting of patient-specific vascular anatomic models. Our framework includes three tools for the creation of tortuosity, aneurysms, and stenoses in tubular vascular geometries. These shape edits are performed via geometric operations on the surface mesh and vessel centerline curves of the input model. The tortuosity tool also uses the physics-based Oriented Particles method, coupled with linear blend skinning, to achieve smooth, elastic-like deformations. Our tools can be applied separately or in combination to produce simulation-suitable morphed models. They are also compatible with popular vascular modeling software, such as simvascular. To illustrate our tools, we morph several image-based, patient-specific models to create a range of shape changes and simulate the resulting hemodynamics via three-dimensional, computational fluid dynamics. We also demonstrate the ability to quickly estimate the hemodynamic effects of the shape changes via the automated generation of associated zero-dimensional lumped-parameter models.
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Affiliation(s)
- Jonathan Pham
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305
| | - Sofia Wyetzner
- Department of Computer Science, Stanford University, Stanford, CA 94305
| | - Martin R Pfaller
- Department of Pediatrics, Stanford University, Stanford, CA 94305
| | - David W Parker
- Stanford Research Computing Center, Stanford University, Stanford, CA 94305
| | - Doug L James
- Department of Computer Science, Stanford University, Stanford, CA 94305
| | - Alison L Marsden
- Department of Bioengineering, Department of Pediatrics, Stanford University, Stanford, CA 94305
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7
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Abdolmanafi A, Forneris A, Moore RD, Di Martino ES. Deep-learning method for fully automatic segmentation of the abdominal aortic aneurysm from computed tomography imaging. Front Cardiovasc Med 2023; 9:1040053. [PMID: 36684599 PMCID: PMC9849751 DOI: 10.3389/fcvm.2022.1040053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 11/28/2022] [Indexed: 01/07/2023] Open
Abstract
Abdominal aortic aneurysm (AAA) is one of the leading causes of death worldwide. AAAs often remain asymptomatic until they are either close to rupturing or they cause pressure to the spine and/or other organs. Fast progression has been linked to future clinical outcomes. Therefore, a reliable and efficient system to quantify geometric properties and growth will enable better clinical prognoses for aneurysms. Different imaging systems can be used to locate and characterize an aneurysm; computed tomography (CT) is the modality of choice in many clinical centers to monitor later stages of the disease and plan surgical treatment. The lack of accurate and automated techniques to segment the outer wall and lumen of the aneurysm results in either simplified measurements that focus on few salient features or time-consuming segmentation affected by high inter- and intra-operator variability. To overcome these limitations, we propose a model for segmenting AAA tissues automatically by using a trained deep learning-based approach. The model is composed of three different steps starting with the extraction of the aorta and iliac arteries followed by the detection of the lumen and other AAA tissues. The results of the automated segmentation demonstrate very good agreement when compared to manual segmentation performed by an expert.
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Affiliation(s)
- Atefeh Abdolmanafi
- R&D Department, ViTAA Medical Solutions, Montreal, QC, Canada,*Correspondence: Atefeh Abdolmanafi ✉
| | - Arianna Forneris
- R&D Department, ViTAA Medical Solutions, Montreal, QC, Canada,Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB, Canada
| | - Randy D. Moore
- R&D Department, ViTAA Medical Solutions, Montreal, QC, Canada,Division of Vascular Surgery, University of Calgary, Calgary, AB, Canada
| | - Elena S. Di Martino
- R&D Department, ViTAA Medical Solutions, Montreal, QC, Canada,Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, Calgary, AB, Canada
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8
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Skov RAC, Eiberg JP, Rouet L, Eldrup N, Zielinski AH, Broda MA, Goetze JP, Ghulam QM. Anticoagulants and reduced thrombus load in abdominal aortic aneurysms assessed with three-dimensional contrast-enhanced ultrasound examination. J Vasc Surg 2023; 77:143-149. [PMID: 35931398 DOI: 10.1016/j.jvs.2022.07.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/30/2022] [Accepted: 07/15/2022] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The relationship between intraluminal thrombus (ILT) and abdominal aortic aneurysm (AAA) growth and rupture risk remains ambiguous. Studies have shown a limited effect of antiplatelet therapy on ILT size, whereas the impact of anticoagulant therapy on ILT is unresolved. This study aims to evaluate an association between antithrombotic therapy and ILT size assessed with three-dimensional contrast-enhanced ultrasound (3D-CEUS) examination in a cohort of patients with AAA. METHODS In a cross-sectional study, 309 patients with small AAAs were examined with 3D-CEUS. Patients were divided into three groups based on prescribed antithrombotic therapy: anticoagulant (n = 36), antiplatelet (n = 222), and no antithrombotic therapy (n = 51). Patient ILT size was calculated in volume and thickness and compared between the three groups. RESULTS Patients on anticoagulants had a significantly lower estimated marginal mean ILT volume of 16 mL (standard error [SE], ±3.2) compared with 28 mL (SE, ±2.7) in the no antithrombotic group and 30 mL (SE, ±1.3) in the antiplatelet group when adjusting for AAA volume (P < .001) and comorbidities (P < .001). In addition, patients on anticoagulant therapy had significantly lower estimated marginal mean ILT thickness of 10 mm (SE, ±1.1) compared with 13 mm (SE, ±0.9) in the no antithrombotic group of and 13mm (SE, ±0.4) in the antiplatelet group when adjusting for AAA diameter (P = .03) and comorbidities (P = .035). CONCLUSIONS A 3D-CEUS examination is applicable for ILT assessment and demonstrates that patients with AAA on anticoagulant therapy have lower ILT thickness and volume than patients with AAA on antiplatelet therapy and those without antithrombotic therapy. Causality between anticoagulants and ILT size, and extrapolation to AAA growth and rupture risk, is unknown and merits further investigations, to further nuance US-based AAA surveillance strategy.
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Affiliation(s)
- Rebecca Andrea Conradsen Skov
- Department of Vascular Surgery, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Copenhagen Academy for Medical Education and Simulation (CAMES), Copenhagen, Denmark.
| | - Jonas P Eiberg
- Department of Vascular Surgery, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Copenhagen Academy for Medical Education and Simulation (CAMES), Copenhagen, Denmark
| | | | - Nikolaj Eldrup
- Department of Vascular Surgery, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Alexander H Zielinski
- Department of Vascular Surgery, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Magdalena A Broda
- Department of Vascular Surgery, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens P Goetze
- Department of Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark; Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Qasam M Ghulam
- Department of Vascular Surgery, Rigshospitalet, Copenhagen, Denmark
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9
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Kim S, Jiang Z, Zambrano BA, Jang Y, Baek S, Yoo S, Chang HJ. Deep Learning on Multiphysical Features and Hemodynamic Modeling for Abdominal Aortic Aneurysm Growth Prediction. IEEE TRANSACTIONS ON MEDICAL IMAGING 2023; 42:196-208. [PMID: 36094984 DOI: 10.1109/tmi.2022.3206142] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Prediction of abdominal aortic aneurysm (AAA) growth is of essential importance for the early treatment and surgical intervention of AAA. Capturing key features of vascular growth, such as blood flow and intraluminal thrombus (ILT) accumulation play a crucial role in uncovering the intricated mechanism of vascular adaptation, which can ultimately enhance AAA growth prediction capabilities. However, local correlations between hemodynamic metrics, biological and morphological characteristics, and AAA growth rates present high inter-patient variability that results in that the temporal-spatial biochemical and mechanical processes are still not fully understood. Hence, this study aims to integrate the physics-based knowledge with deep learning with a patch-based convolutional neural network (CNN) approach by incorporating important multiphysical features relating to its pathogenesis for validating its impact on AAA growth prediction. For this task, we observe that the unstructured multiphysical features cannot be directly employed in the kernel-based CNN. To tackle this issue, we propose a parameterization of features to leverage the spatio-temporal relations between multiphysical features. The proposed architecture was tested on different combinations of four features including radius, intraluminal thrombus thickness, time-average wall shear stress, and growth rate from 54 patients with 5-fold cross-validation with two metrics, a root mean squared error (RMSE) and relative error (RE). We conduct extensive experiments on AAA patients, the results show the effect of leveraging multiphysical features and demonstrate the superiority of the presented architecture to previous state-of-the-art methods in AAA growth prediction.
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10
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Throop A, Bukac M, Zakerzadeh R. Prediction of wall stress and oxygen flow in patient-specific abdominal aortic aneurysms: the role of intraluminal thrombus. Biomech Model Mechanobiol 2022; 21:1761-1779. [PMID: 35908098 DOI: 10.1007/s10237-022-01618-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 07/13/2022] [Indexed: 11/28/2022]
Abstract
In this study, the biomechanical role of intraluminal thrombus (ILT) in an abdominal aortic aneurysm (AAA) is investigated. The implications of ILT in AAA are controversial in literature. Previous studies have demonstrated that ILT provides a biomechanical advantage by decreasing wall stress, whereas other studies have associated ILT with inhibiting oxygen transport and inducing aortic wall weakening. Therefore, we sought to explore the connection between ILT, mechanical stresses, and oxygen flow in different geometries of patient-specific aneurysms with varying ILT morphologies. The objective is to investigate the extent to which ILT influences the prediction of aneurysmal wall stresses that are associated with rupture, as well as oxygen concentrations to measure tissue oxygen deprivation. Three patient-specific AAA geometries are considered, and two models, one with ILT and one without ILT, are created for each patient to assess the effect of ILT presence. A fluid-structure interaction approach is used to couple the blood flow, wall deformation, and oxygen mass transport. Results are presented for hemodynamics patterns, wall stress measures, and oxygen metrics within the arterial wall. While ILT is found to reduce wall stress, simulations confirm that ILT decreases oxygen transport within the tissue significantly, leading to wall hypoxia.
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Affiliation(s)
- Alexis Throop
- Department of Engineering, Rangos School of Health Sciences, Duquesne University, 413 Libermann Hall, 600 Forbes Avenue, Pittsburgh, PA, 15282, USA
| | - Martina Bukac
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, IN, USA
| | - Rana Zakerzadeh
- Department of Engineering, Rangos School of Health Sciences, Duquesne University, 413 Libermann Hall, 600 Forbes Avenue, Pittsburgh, PA, 15282, USA.
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11
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The Detrimental Role of Intraluminal Thrombus Outweighs Protective Advantage in Abdominal Aortic Aneurysm Pathogenesis: The Implications for the Anti-Platelet Therapy. Biomolecules 2022; 12:biom12070942. [PMID: 35883500 PMCID: PMC9313225 DOI: 10.3390/biom12070942] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/20/2022] [Accepted: 07/01/2022] [Indexed: 02/01/2023] Open
Abstract
Abdominal aortic aneurysm (AAA) is a common cardiovascular disease resulting in morbidity and mortality in older adults due to rupture. Currently, AAA treatment relies entirely on invasive surgical treatments, including open repair and endovascular, which carry risks for small aneurysms (diameter < 55 mm). There is an increasing need for the development of pharmacological intervention for early AAA. Over the last decade, it has been increasingly recognized that intraluminal thrombus (ILT) is involved in the growth, remodeling, and rupture of AAA. ILT has been described as having both biomechanically protective and biochemically destructive properties. Platelets are the second most abundant cells in blood circulation and play an integral role in the formation, expansion, and proteolytic activity of ILT. However, the role of platelets in the ILT-potentiated AAA progression/rupture remains unclear. Researchers are seeking pharmaceutical treatment strategies (e.g., anti-thrombotic/anti-platelet therapies) to prevent ILT formation or expansion in early AAA. In this review, we mainly focus on the following: (a) the formation/deposition of ILT in the progression of AAA; (b) the dual role of ILT in the progression of AAA (protective or detrimental); (c) the function of platelet activity in ILT formation; (d) the application of anti-platelet drugs in AAA. Herein, we present challenges and future work, which may motivate researchers to better explain the potential role of ILT in the pathogenesis of AAA and develop anti-platelet drugs for early AAA.
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12
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Correlation Between Proteolytic Activity and Abdominal Aortic Aneurysm Wall Morphology with Intraluminal Thrombus Volume. Ann Vasc Surg 2022; 87:487-494. [PMID: 35779804 DOI: 10.1016/j.avsg.2022.05.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/19/2022] [Accepted: 05/26/2022] [Indexed: 11/24/2022]
Abstract
BACKGROUND The aim of this study was to examine the influence of intraluminal thrombus (ILT) volume on the level of proteolytic activity and the content of abdominal aortic aneurysm (AAA) wall. METHODS The research was designed as a cross-sectional study at the Clinic for Vascular and Endovascular Surgery, Clinical Center of Serbia in the period from April 2017 to February 2018. During this period, a total of 155 patients with asymptomatic AAA underwent open surgical treatment and 50 were included in the study based on inclusion and exclusion criteria. Before surgery, patients included in the study were examined by MRI. During the operation, samples of ILT and AAA wall were taken for biochemical analysis. RESULTS A statistically significant correlation was found between the volume of the ILT and largest AAA diameter (ρ = 0.56; P < 0.001). The correlation of the ILT volume on the anterior wall and the concentration of MMP-9, MMP-2 and NE/ELA in the wall did not find statistical significance. Also, no statistically significant association was found between the volume of ILT and the concentration of ECM proteins (collagen type 3, elastin, proteoglycan) in the corresponding part of the wall. The association of ILT volume with MDA was also of no statistical significance. There was a positive statistical significance found in correlation of volume of ILT and catalase activity in the wall of AAA (ρ = 0.28, P = 0.049). CONCLUSIONS The volume of ILT in the aneurysmal sac seemed not to affect the level of proteolytic activity and the content of the aneurysm wall. However, a positive correlation was found between the ILT and the catalase activity. The effect of ILT on the aneurysm wall and its role in the progression of aneurysmal disease should be examined in future studies.
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13
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Numerical investigation of abdominal aortic aneurysm hemodynamics using the reduced unified continuum formulation for vascular fluid-structure interaction. FORCES IN MECHANICS 2022. [DOI: 10.1016/j.finmec.2022.100089] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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14
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Carbino B, Guy A, Durka M, Zakerzadeh R. The Effects of Geometric Features of Intraluminal Thrombus on the Vessel Wall Oxygen Deprivation. Front Bioeng Biotechnol 2022; 10:814995. [PMID: 35419349 PMCID: PMC8997837 DOI: 10.3389/fbioe.2022.814995] [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: 11/14/2021] [Accepted: 02/21/2022] [Indexed: 12/20/2022] Open
Abstract
The objective of this paper is to analyze the association of intraluminal thrombus (ILT) presence and morphology with oxygen transport in abdominal aortic aneurysms (AAA) and local hypoxia. The biomechanical role of the ILT layer in the evolution of the aneurysm is still not fully understood. ILT has been shown to create an inflammatory environment by reducing oxygen flux to the arterial wall and therefore decreasing its strength. It has been also hypothesized that the geometry of the ILT may further affect AAA rupture. However, no previous research has attempted to explore the effect of morphological features of ILT on oxygen distributions within the AAA, in a systematic manner. In this study, we perform a comprehensive analysis to investigate how physiologically meaningful variations in ILT geometric characteristics affect oxygen transport within an AAA. We simulate twenty-seven AAA models with variable ILT dimensions and investigate the extent to which ILT attenuates oxygen concentration in the arterial wall. Geometric variations studied include ILT thickness and ILT length, as well as the bulge diameter of the aneurysm which is related to ILT curvature. Computer simulations of coupled fluid flow-mass transport between arterial wall, ILT, and blood are solved and spatial variations of oxygen concentrations within the ILT and wall are obtained. The comparison of the results for all twenty-seven simulations supports the hypothesis that the presence of ILT in AAA correlates to significantly impaired oxygen transport to the aneurysmal wall. Mainly, we observed that ILT thickness and length are the parameters that influence decreased oxygen flow and concentration values the most, and thick thrombi exacerbate hypoxic conditions in the arterial wall, which may contribute to increased tissue degradation. Conversely, we observed that the arterial wall oxygen concentration is nearly independent of the AAA bulge diameter. This confirms that consideration of ILT size and anatomy is crucial in the analysis of AAA development.
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Affiliation(s)
- Burton Carbino
- Department of Engineering, Rangos School of Health Sciences, Duquesne University, Pittsburgh, PA, United States
| | - Alexander Guy
- Department of Engineering, Rangos School of Health Sciences, Duquesne University, Pittsburgh, PA, United States
| | - Michael Durka
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
- Department of Mechanical Engineering and Materials Science, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Rana Zakerzadeh
- Department of Engineering, Rangos School of Health Sciences, Duquesne University, Pittsburgh, PA, United States
- *Correspondence: Rana Zakerzadeh,
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15
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Živić J, Virag L, Horvat N, Smoljkić M, Karšaj I. The risk of rupture and abdominal aortic aneurysm morphology: A computational study. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2022; 38:e3566. [PMID: 34919341 DOI: 10.1002/cnm.3566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 11/18/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
Prediction of rupture and optimal timing for abdominal aortic aneurysm (AAA) surgical intervention remain wanting even after decades of clinical, histological, and numerical research. Although studies estimating rupture from AAA geometrical features from CT imaging showed some promising results, they are still not being used in practice. Patient-specific numerical stress analysis introduced too many assumptions about wall structure for the related rupture potential index (RPI) to be considered reliable. Growth and remodeling (G&R) numerical models eliminate some of these assumptions and thus might have the most potential to calculate mural stresses and RPI and increase our understanding of rupture. To recognize numerical models as trustworthy, it is necessary to validate the computed results with results derived from imaging. Elastin degradation function is one of the main factors that determine idealized aneurysm sac shape. Using a hundred different combinations of variables defining AAA geometry or influences AAA stability (elastin degradation function parameters, collagen mechanics, and initial healthy aortic diameters), we investigated the relationship between AAA morphology and RPI and compared numerical results with clinical findings. Good agreement of numerical results with clinical expectations from the literature gives us confidence in the validity of the numerical model. We show that aneurysm morphology significantly influences the stability of aneurysms. Additionally, we propose new parameters, geometrical rupture potential index (GRPI) and normalized aneurysm length (NAL), that might predict rupture of aneurysms without thrombus better than currently used criteria (i.e., maximum diameter and growth rate). These parameters can be computed quickly, without the tedious processing of CT images.
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Affiliation(s)
- Josip Živić
- Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Zagreb, Croatia
| | - Lana Virag
- Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Zagreb, Croatia
| | - Nino Horvat
- Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Zagreb, Croatia
| | | | - Igor Karšaj
- Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Zagreb, Croatia
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16
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Siennicka A, Adamowicz M, Grzesch N, Kłysz M, Woźniak J, Cnotliwy M, Galant K, Jastrzębska M. Association of Aneurysm Tissue Neutrophil Mediator Levels with Intraluminal Thrombus Thickness in Patients with Abdominal Aortic Aneurysm. Biomolecules 2022; 12:biom12020254. [PMID: 35204755 PMCID: PMC8961541 DOI: 10.3390/biom12020254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/26/2022] [Accepted: 02/02/2022] [Indexed: 12/04/2022] Open
Abstract
An intraluminal thrombus (ILT), which accumulates large numbers of neutrophils, plays a key role in abdominal aortic aneurysm (AAA) pathogenesis. This study aimed to compare levels of selected neutrophil inflammatory mediators in thick and thin ILT, plus adjacent AAA walls, to determine whether levels depend on ILT thickness. Neutrophil mediator levels were analysed by enzyme-linked immunosorbent assays in thick and thin segments of ILT, plus adjacent aneurysm wall sections, taken from one aneurysm sac each from 36 AAA patients. In aneurysmal walls covered by thick ILT, neutrophil elastase and TNF-a levels were significantly higher, as were concentrations of IL-6, in thick ILT compared to thin layers. Positive correlations of NGAL, MPO, and neutrophil elastase were observed between thick ILT and the adjacent wall and thin ILT and the adjacent wall, suggesting that these mediators probably infiltrate thick AAA compartments as well as thin. These observations might support the idea that neutrophil mediators and inflammatory cytokines differentially accumulate in AAA tissues according to ILT thickness. The increased levels of neutrophil mediators within thicker AAA segments might suggest the existence of an intensified proinflammatory state that in turn presumably might preferentially weaken the AAA wall at that region.
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Affiliation(s)
- Aldona Siennicka
- Department of Laboratory Diagnostics, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland; (A.S.); (M.A.); (N.G.); (M.J.)
| | - Monika Adamowicz
- Department of Laboratory Diagnostics, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland; (A.S.); (M.A.); (N.G.); (M.J.)
| | - Natalie Grzesch
- Department of Laboratory Diagnostics, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland; (A.S.); (M.A.); (N.G.); (M.J.)
| | - Magdalena Kłysz
- Department of Laboratory Diagnostics, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland; (A.S.); (M.A.); (N.G.); (M.J.)
- Correspondence: ; Tel.: +48-914661505
| | - Jarosław Woźniak
- Institute of Mathematics, University of Szczecin, Wielkopolska 15, 70-451 Szczecin, Poland;
| | - Miłosław Cnotliwy
- Department of Vascular Surgery and Angiology, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland;
| | - Katarzyna Galant
- Department of Laboratory Medicine, Chair of Microbiology, Immunological Diagnostics and Laboratory Medicine, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland;
| | - Maria Jastrzębska
- Department of Laboratory Diagnostics, Pomeranian Medical University, Powstańców Wlkp. 72, 70-111 Szczecin, Poland; (A.S.); (M.A.); (N.G.); (M.J.)
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17
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Li H, Deng Y, Sampani K, Cai S, Li Z, Sun JK, Karniadakis GE. Computational investigation of blood cell transport in retinal microaneurysms. PLoS Comput Biol 2022; 18:e1009728. [PMID: 34986147 PMCID: PMC8730408 DOI: 10.1371/journal.pcbi.1009728] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 12/07/2021] [Indexed: 12/15/2022] Open
Abstract
Microaneurysms (MAs) are one of the earliest clinically visible signs of diabetic retinopathy (DR). MA leakage or rupture may precipitate local pathology in the surrounding neural retina that impacts visual function. Thrombosis in MAs may affect their turnover time, an indicator associated with visual and anatomic outcomes in the diabetic eyes. In this work, we perform computational modeling of blood flow in microchannels containing various MAs to investigate the pathologies of MAs in DR. The particle-based model employed in this study can explicitly represent red blood cells (RBCs) and platelets as well as their interaction in the blood flow, a process that is very difficult to observe in vivo. Our simulations illustrate that while the main blood flow from the parent vessels can perfuse the entire lumen of MAs with small body-to-neck ratio (BNR), it can only perfuse part of the lumen in MAs with large BNR, particularly at a low hematocrit level, leading to possible hypoxic conditions inside MAs. We also quantify the impacts of the size of MAs, blood flow velocity, hematocrit and RBC stiffness and adhesion on the likelihood of platelets entering MAs as well as their residence time inside, two factors that are thought to be associated with thrombus formation in MAs. Our results show that enlarged MA size, increased blood velocity and hematocrit in the parent vessel of MAs as well as the RBC-RBC adhesion promote the migration of platelets into MAs and also prolong their residence time, thereby increasing the propensity of thrombosis within MAs. Overall, our work suggests that computational simulations using particle-based models can help to understand the microvascular pathology pertaining to MAs in DR and provide insights to stimulate and steer new experimental and computational studies in this area.
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Affiliation(s)
- He Li
- School of Engineering, Brown University, Providence, Rhode Island, United States of America
| | - Yixiang Deng
- School of Engineering, Brown University, Providence, Rhode Island, United States of America
| | - Konstantina Sampani
- Beetham Eye Institute, Joslin Diabetes Center, Boston, Massachusetts, United States of America
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Shengze Cai
- Division of Applied Mathematics, Brown University, Providence, Rhode Island, United States of America
| | - Zhen Li
- Department of Mechanical Engineering, Clemson University, Clemson, South Carolina, United States of America
| | - Jennifer K. Sun
- Beetham Eye Institute, Joslin Diabetes Center, Boston, Massachusetts, United States of America
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - George E. Karniadakis
- School of Engineering, Brown University, Providence, Rhode Island, United States of America
- Division of Applied Mathematics, Brown University, Providence, Rhode Island, United States of America
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18
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Weiss D, Latorre M, Rego BV, Cavinato C, Tanski BJ, Berman AG, Goergen CJ, Humphrey JD. Biomechanical consequences of compromised elastic fiber integrity and matrix cross-linking on abdominal aortic aneurysmal enlargement. Acta Biomater 2021; 134:422-434. [PMID: 34332103 DOI: 10.1016/j.actbio.2021.07.059] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/07/2021] [Accepted: 07/23/2021] [Indexed: 12/25/2022]
Abstract
Abdominal aortic aneurysms (AAAs) are characterized histopathologically by compromised elastic fiber integrity, lost smooth muscle cells or their function, and remodeled collagen. We used a recently introduced mouse model of AAAs that combines enzymatic degradation of elastic fibers and blocking of lysyl oxidase, and thus matrix cross-linking, to study progressive dilatation of the infrarenal abdominal aorta, including development of intraluminal thrombus. We quantified changes in biomaterial properties and biomechanical functionality within the aneurysmal segment as a function of time of enlargement and degree of thrombosis. Towards this end, we combined multi-modality imaging with state-of-the art biomechanical testing and histology to quantify regional heterogeneities for the first time and we used a computational model of arterial growth and remodeling to test multiple hypotheses, suggested by the data, regarding the degree of lost elastin, accumulation of glycosaminoglycans, and rates of collagen turnover. We found that standard histopathological findings can be misleading, while combining advanced experimental and computational methods revealed that glycosaminoglycan accumulation is pathologic, not adaptive, and that heightened collagen deposition is ineffective if not cross-linked. In conclusion, loss of elastic fiber integrity can be a strong initiator of aortic aneurysms, but it is the rate and effectiveness of fibrillar collagen remodeling that dictates enlargement. STATEMENT OF SIGNIFICANCE: Precise mechanisms by which abdominal aortic aneurysms enlarge remain unclear, but a recent elastase plus β-aminopropionitrile mouse model provides new insight into disease progression. As in the human condition, the aortic degeneration and adverse remodeling are highly heterogeneous in this model. Our multi-modality experiments quantify and contrast the heterogeneities in geometry and biomaterial properties, and our computational modeling shows that standard histopathology can be misleading. Neither accumulating glycosaminoglycans nor frustrated collagen synthesis slow disease progression, thus highlighting the importance of stimulating adaptive collagen remodeling to limit lesion enlargement.
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Affiliation(s)
- D Weiss
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - M Latorre
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - B V Rego
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - C Cavinato
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - B J Tanski
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - A G Berman
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - C J Goergen
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - J D Humphrey
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA; Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA.
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19
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Teeraratkul C, Mukherjee D. Microstructure aware modeling of biochemical transport in arterial blood clots. J Biomech 2021; 127:110692. [PMID: 34479090 DOI: 10.1016/j.jbiomech.2021.110692] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/14/2021] [Accepted: 08/09/2021] [Indexed: 01/29/2023]
Abstract
Flow-mediated transport of biochemical species is central to thrombotic phenomena. Comprehensive three-dimensional modeling of flow-mediated transport around realistic macroscale thrombi poses challenges owing to their arbitrary heterogeneous microstructure. Here, we develop a microstructure aware model for species transport within and around a macroscale thrombus by devising a custom preconditioned fictitious domain formulation for thrombus-hemodynamics interactions, and coupling it with a fictitious domain advection-diffusion formulation for transport. Microstructural heterogeneities are accounted through a hybrid discrete particle-continuum approach for the thrombus interior. We present systematic numerical investigations on unsteady arterial flow within and around a three-dimensional macroscale thrombus; demonstrate the formation of coherent flow structures around the thrombus which organize advective transport; illustrate the role of the permeation processes at the thrombus boundary and subsequent intra-thrombus transport; and characterize species transport from bulk flow to the thrombus boundary and vice versa.
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Affiliation(s)
- Chayut Teeraratkul
- Paul M Rady Department of Mechanical Engineering, University of Colorado Boulder, United States of America.
| | - Debanjan Mukherjee
- Paul M Rady Department of Mechanical Engineering, University of Colorado Boulder, United States of America.
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20
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Searle AK, Chen YC, Wallert M, McFadyen J, Maluenda A, Noonan J, Kanellakis P, Zaldivia MT, Huang A, Lioe H, Biondo M, Nolte MW, Rossato P, Bobik A, Panousis C, Wang X, Hosseini H, Peter K. Pharmacological inhibition of Factor XIIa attenuates abdominal aortic aneurysm, reduces atherosclerosis, and stabilizes atherosclerotic plaques. Thromb Haemost 2021; 122:196-207. [PMID: 34619795 PMCID: PMC8820844 DOI: 10.1055/a-1663-8208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Background
3F7 is a monoclonal antibody targeting the enzymatic pocket of activated factor XII (FXIIa), thereby inhibiting its catalytic activity. Given the emerging role of FXIIa in promoting thromboinflammation, along with its apparent redundancy for hemostasis, the selective inhibition of FXIIa represents a novel and highly attractive approach targeting pathogenic processes that cause thromboinflammation-driven cardiovascular diseases.
Methods
The effects of FXIIa inhibition were investigated using three distinct mouse models of cardiovascular disease—angiotensin II-induced abdominal aortic aneurysm (AAA), an ApoE
−/−
model of atherosclerosis, and a tandem stenosis model of atherosclerotic plaque instability. 3F7 or its isotype control, BM4, was administered to mice (10 mg/kg) on alternate days for 4 to 8 weeks, depending on the experimental model. Mice were examined for the development and size of AAAs, or the burden and instability of atherosclerosis and associated markers of inflammation.
Results
Inhibition of FXIIa resulted in a reduced incidence of larger AAAs, with less acute aortic ruptures and an associated fibro-protective phenotype. FXIIa inhibition also decreased stable atherosclerotic plaque burden and achieved plaque stabilization associated with increased deposition of fibrous structures, a >2-fold thicker fibrous cap, increased cap-to-core ratio, and reduction in localized and systemic inflammatory markers.
Conclusion
Inhibition of FXIIa attenuates disease severity across three mouse models of thromboinflammation-driven cardiovascular diseases. Specifically, the FXIIa-inhibiting monoclonal antibody 3F7 reduces AAA severity, inhibits the development of atherosclerosis, and stabilizes vulnerable plaques. Ultimately, clinical trials in patients with cardiovascular diseases such as AAA and atherosclerosis are warranted to demonstrate the therapeutic potential of FXIIa inhibition.
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Affiliation(s)
- Amy K Searle
- Atherothrombosis and Vascular Biology, Baker Heart Research Institute - BHRI, Melbourne, Australia
| | - Yung Chih Chen
- Atherothrombosis and Vascular Biology, Baker Heart Research Institute - BHRI, Melbourne, Australia
| | - Maria Wallert
- Atherothrombosis and Vascular Biology, Baker Heart Research Institute - BHRI, Melbourne, Australia
| | - James McFadyen
- Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Ana Maluenda
- Atherothrombosis and Vascular Biology, Baker Heart Research Institute - BHRI, Melbourne, Australia
| | - Jonathan Noonan
- Atherothrombosis and Vascular Biology, Baker Heart Research Institute - BHRI, Melbourne, Australia
| | - Peter Kanellakis
- Atherosclerosis and Cell Biology, Baker Heart Research Institute - BHRI, Melbourne, Australia
| | - Maria Tk Zaldivia
- Atherothrombosis and Vascular Biology, Baker Heart Research Institute - BHRI, Melbourne, Australia
| | - Angela Huang
- Atherothrombosis and Vascular Biology, Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Hadi Lioe
- Bio21 Institute, CSL Limited, Parkville, Australia
| | - Mark Biondo
- Bio21 Institute, CSL Limited, Parkville, Australia
| | | | | | - Alex Bobik
- Atherosclerosis and Cell Biology, Baker Heart Research Institute - BHRI, Melbourne, Australia
| | - Con Panousis
- Bio21 Institute, CSL Limited, Parkville, Australia
| | - Xiaowei Wang
- Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Hamid Hosseini
- Atherothrombosis and Vascular Biology, Baker Heart Research Institute - BHRI, Melbourne, Australia
| | - Karlheinz Peter
- Atherothrombosis and Vascular Biology, Baker Heart Research Institute - BHRI, Melbourne, Australia
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21
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Horvat N, Virag L, Karšaj I. Mechanical role of intraluminal thrombus in aneurysm growth: A computational study. Biomech Model Mechanobiol 2021; 20:1819-1832. [PMID: 34148166 DOI: 10.1007/s10237-021-01478-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 06/07/2021] [Indexed: 12/25/2022]
Abstract
Models that seek to improve our current understanding of biochemical processes and predict disease progression have been increasingly in use over the last decades. Recently, we proposed a finite element implementation of arterial wall growth and remodeling with application to abdominal aortic aneurysms (AAAs). The study focused on changes within the aortic wall and did not include the complex role of intraluminal thrombus (ILT) during the AAA evolution. Thus, in this work, we extend the model with a gradual deposition of ILT and its mechanical influence on AAA growth. Despite neglecting the increased biochemical activity due to the presence of a proteolytically active luminal layer of ILT, and thus underestimating rupture risk potential, we show that ILT helps to slow down the growth of the aneurysm in the axial direction by redirecting blood pressure loading from the axial-radial plane to predominately radial direction. This very likely lowers rupture potential. We also show that the ratio of ILT volume to volume sac is an important factor in AAA stabilization and that fully thrombosed aneurysms could stabilize quicker and at smaller maximum diameters compared to partially thrombosed ones. Furthermore, we show that ILT formation and the associated mural stress decrease negatively impact the wall constituent production and thickness. Although further studies that include increased biochemical degradation of the wall after the formation of ILT and ILT deposition based on hemodynamics are needed, the present findings highlight the dual role an ILT plays during AAA progression.
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Affiliation(s)
- Nino Horvat
- Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Ivana Lučića 5, 10000, Zagreb, Croatia
| | - Lana Virag
- Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Ivana Lučića 5, 10000, Zagreb, Croatia
| | - Igor Karšaj
- Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Ivana Lučića 5, 10000, Zagreb, Croatia.
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Boyd AJ. Intraluminal thrombus: Innocent bystander or factor in abdominal aortic aneurysm pathogenesis? JVS Vasc Sci 2021; 2:159-169. [PMID: 34617066 PMCID: PMC8489244 DOI: 10.1016/j.jvssci.2021.02.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 02/20/2021] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Abdominal aortic aneurysms (AAAs) represent a complex multifactorial hemodynamic, thrombotic, and inflammatory process that can ultimately result in aortic rupture and death. Despite improved screening and surgical management of AAAs, the mortality rates have remained high after rupture, and little progress has occurred in the development of nonoperative treatments. Intraluminal thrombus (ILT) is present in most AAAs and might be involved in AAA pathogenesis. The present review examined the latest clinical and experimental evidence for possible involvement of the ILT in AAA growth and rupture. METHODS A literature review was performed after a search of the PubMed database from 2012 to June 2020 using the terms "abdominal aortic aneurysm" and "intraluminal thrombus." RESULTS The structure, composition, and hemodynamics of ILT formation and propagation were reviewed in relation to the hemostatic and proteolytic factors favoring ILT deposition. The potential effects of the ILT on AAA wall degeneration and rupture, including a review of the current controversies regarding the position, thickness, and composition of ILT, are presented. Although initially potentially protective against increased wall stress, increasing evidence has shown that an increased volume and greater age of the ILT have direct detrimental effects on aortic wall integrity, which might predispose to an increased rupture risk. CONCLUSIONS ILT does not appear to be an innocent bystander in AAA pathophysiology. However, its exact role remains elusive and controversial. Despite computational evidence of a possible protective role of the ILT in reducing wall stress, increasing evidence has shown that the ILT promotes AAA wall degeneration in humans and in animal models. Further research, with large animal models and with more chronic ILT is crucial for a better understanding of the role of the ILT in AAAs and for the potential development of targeted therapies to slow or halt AAA progression.
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Affiliation(s)
- April J. Boyd
- Department of Vascular Surgery, University of Manitoba, Winnipeg, Manitoba, Canada
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23
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Niemann A, Voß S, Tulamo R, Weigand S, Preim B, Berg P, Saalfeld S. Complex wall modeling for hemodynamic simulations of intracranial aneurysms based on histologic images. Int J Comput Assist Radiol Surg 2021; 16:597-607. [PMID: 33715047 PMCID: PMC8052238 DOI: 10.1007/s11548-021-02334-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 02/25/2021] [Indexed: 12/04/2022]
Abstract
Purpose For the evaluation and rupture risk assessment of intracranial aneurysms, clinical, morphological and hemodynamic parameters are analyzed. The reliability of intracranial hemodynamic simulations strongly depends on the underlying models. Due to the missing information about the intracranial vessel wall, the patient-specific wall thickness is often neglected as well as the specific physiological and pathological properties of the vessel wall. Methods In this work, we present a model for structural simulations with patient-specific wall thickness including different tissue types based on postmortem histologic image data. Images of histologic 2D slices from intracranial aneurysms were manually segmented in nine tissue classes. After virtual inflation, they were combined into 3D models. This approach yields multiple 3D models of the inner and outer wall and different tissue parts as a prerequisite for subsequent simulations. Result We presented a pipeline to generate 3D models of aneurysms with respect to the different tissue textures occurring in the wall. First experiments show that including the variance of the tissue in the structural simulation affect the simulation result. Especially at the interfaces between neighboring tissue classes, the larger influence of stiffer components on the stability equilibrium became obvious. Conclusion The presented approach enables the creation of a geometric model with differentiated wall tissue. This information can be used for different applications, like hemodynamic simulations, to increase the modeling accuracy.
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Affiliation(s)
- Annika Niemann
- Faculty of Computer Science, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, D-39106, Magdeburg, Germany.
| | - Samuel Voß
- Laboratory of Fluid Dynamics and Technical Flows, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Riikka Tulamo
- Department of Vascular Surgery, and Neurosurgery Research Group, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Simon Weigand
- Department of General, Visceral and Transplantation Surgery, Hospital of the University of Munich, Campus Grosshadern, Munich, Germany
| | - Bernhard Preim
- Faculty of Computer Science, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, D-39106, Magdeburg, Germany
| | - Philipp Berg
- Laboratory of Fluid Dynamics and Technical Flows, Otto-von-Guericke University Magdeburg, Magdeburg, Germany.,Forschungscampus STIMULATE, Magdeburg, Germany
| | - Sylvia Saalfeld
- Faculty of Computer Science, Otto-von-Guericke University Magdeburg, Universitätsplatz 2, D-39106, Magdeburg, Germany.,Forschungscampus STIMULATE, Magdeburg, Germany
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24
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Li H, Sampani K, Zheng X, Papageorgiou DP, Yazdani A, Bernabeu MO, Karniadakis GE, Sun JK. Predictive modelling of thrombus formation in diabetic retinal microaneurysms. ROYAL SOCIETY OPEN SCIENCE 2020; 7:201102. [PMID: 32968536 PMCID: PMC7481715 DOI: 10.1098/rsos.201102] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 07/29/2020] [Indexed: 06/11/2023]
Abstract
Microaneurysms (MAs) are one of the earliest clinically visible signs of diabetic retinopathy (DR). Vision can be reduced at any stage of DR by MAs, which may enlarge, rupture and leak fluid into the neural retina. Recent advances in ophthalmic imaging techniques enable reconstruction of the geometries of MAs and quantification of the corresponding haemodynamic metrics, such as shear rate and wall shear stress, but there is lack of computational models that can predict thrombus formation in individual MAs. In this study, we couple a particle model to a continuum model to simulate the platelet aggregation in MAs with different shapes. Our simulation results show that under a physiologically relevant blood flow rate, thrombosis is more pronounced in saccular-shaped MAs than fusiform-shaped MAs, in agreement with recent clinical findings. Our model predictions of the size and shape of the thrombi in MAs are consistent with experimental observations, suggesting that our model is capable of predicting the formation of thrombus for newly detected MAs. This is the first quantitative study of thrombosis in MAs through simulating platelet aggregation, and our results suggest that computational models can be used to predict initiation and development of intraluminal thrombus in MAs as well as provide insights into their role in the pathophysiology of DR.
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Affiliation(s)
- He Li
- Division of Applied Mathematics, Brown University, Providence, RI 02912, USA
| | - Konstantina Sampani
- Beetham Eye Institute, Joslin Diabetes Center, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Xiaoning Zheng
- Division of Applied Mathematics, Brown University, Providence, RI 02912, USA
| | - Dimitrios P. Papageorgiou
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Alireza Yazdani
- Division of Applied Mathematics, Brown University, Providence, RI 02912, USA
| | - Miguel O. Bernabeu
- Centre for Medical Informatics, Usher Institute, University of Edinburgh, Edinburgh, UK
| | | | - Jennifer K. Sun
- Beetham Eye Institute, Joslin Diabetes Center, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
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25
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Xiao J, Liu J, Lio I, Yang C, Chen X, Zhang H, Wang S, Wei Z. All-trans retinoic acid attenuates the progression of Ang II-induced abdominal aortic aneurysms in ApoE -/-mice. J Cardiothorac Surg 2020; 15:160. [PMID: 32615991 PMCID: PMC7331218 DOI: 10.1186/s13019-020-01208-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 06/23/2020] [Indexed: 12/20/2022] Open
Abstract
Background To determine whether all-trans retinoic acid (ATRA) can influence the development of Angiotensin II (Ang II) induced experimental abdominal aortic aneurysms (AAAs). Methods Apolipoprotein E knock-out (ApoE−/−) mice were randomly assigned to 4 groups. Mice in the AAA and ATRA groups underwent continuous subcutaneous Ang II infusion for 28 days to induce AAA, while the Sham and Control groups were infused with saline. Systolic blood pressure was measured by the tail-cuff technique. The Control and ATRA groups received ATRA treatment. Aortic tissue samples were obtained at 28 days after surgery and evaluated by aortic diameter measurement, Western blotting, immunohistochemistry, and hematoxylin-eosin (H&E) and Verhoeff-Van Gieson (EVG) staining. Results The abdominal aortic diameter was significantly reduced in the ATRA group compared with the AAA group (3 of 12 (25%) vs 9 of 12 (75%), P < 0.05), and the ATRA group exhibited reduced blood pressure on days 7, 14, and 28. Low expression of angiotensin II receptor type 1 (AT1), matrix metalloproteinase 2 (MMP2), and matrix metalloproteinase 9 (MMP9) and EVG staining revealed a significant reduction in the disruption of elastic fibers in the abdominal aortic tissue of the ATRA group compared to the AAA group. Western blot analysis indicated that protein levels of retinoic acid receptor α (RARα), MMP2, MMP9, and AT1 were dramatically affected by ATRA treatment. Conclusions In conclusion, ATRA attenuates the progression of Ang II-induced AAAs, possibly by downregulating MMP2, MMP9, and AT-1 expression.
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Affiliation(s)
- Jie Xiao
- Department of Cardiovascular Surgery, Central Hospital of Wuhan, Huazhong University of Science and Technology, Wuhan, 430014, China
| | - Jinping Liu
- Department of Cardiovascular Surgery, Zhongnan Hospital, Wuhan University, Wuhan, 430071, Hubei, China
| | - Iohang Lio
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Chuanlei Yang
- Department of Cardiovascular Surgery, Central Hospital of Wuhan, Huazhong University of Science and Technology, Wuhan, 430014, China
| | - Xing Chen
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Hua Zhang
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Shuxia Wang
- Department of Radiology, Central Hospital of Wuhan, Huazhong University of Science and Technology, Wuhan, 430014, China.
| | - Zhanjie Wei
- Department of General Surgery, Central Hospital of Wuhan, Huazhong University of Science and Technology, Wuhan, 430014, China.
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Zheng X, Yazdani A, Li H, Humphrey JD, Karniadakis GE. A three-dimensional phase-field model for multiscale modeling of thrombus biomechanics in blood vessels. PLoS Comput Biol 2020; 16:e1007709. [PMID: 32343724 PMCID: PMC7224566 DOI: 10.1371/journal.pcbi.1007709] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 05/14/2020] [Accepted: 02/03/2020] [Indexed: 01/10/2023] Open
Abstract
Mechanical interactions between flowing and coagulated blood (thrombus) are crucial in dictating the deformation and remodeling of a thrombus after its formation in hemostasis. We propose a fully-Eulerian, three-dimensional, phase-field model of thrombus that is calibrated with existing in vitro experimental data. This phase-field model considers spatial variations in permeability and material properties within a single unified mathematical framework derived from an energy perspective, thereby allowing us to study effects of thrombus microstructure and properties on its deformation and possible release of emboli under different hemodynamic conditions. Moreover, we combine this proposed thrombus model with a particle-based model which simulates the initiation of the thrombus. The volume fraction of a thrombus obtained from the particle simulation is mapped to an input variable in the proposed phase-field thrombus model. The present work is thus the first computational study to integrate the initiation of a thrombus through platelet aggregation with its subsequent viscoelastic responses to various shear flows. This framework can be informed by clinical data and potentially be used to predict the risk of diverse thromboembolic events under physiological and pathological conditions.
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Affiliation(s)
- Xiaoning Zheng
- Division of Applied Mathematics, Brown University, Providence, Rhode Island, United States of America
| | - Alireza Yazdani
- Division of Applied Mathematics, Brown University, Providence, Rhode Island, United States of America
| | - He Li
- Division of Applied Mathematics, Brown University, Providence, Rhode Island, United States of America
| | - Jay D. Humphrey
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, United States of America
| | - George E. Karniadakis
- Division of Applied Mathematics, Brown University, Providence, Rhode Island, United States of America
- * E-mail:
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27
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A novel combined fluid dynamic and strain analysis approach identified abdominal aortic aneurysm rupture. JOURNAL OF VASCULAR SURGERY CASES INNOVATIONS AND TECHNIQUES 2020; 6:172-176. [PMID: 32322769 PMCID: PMC7160522 DOI: 10.1016/j.jvscit.2020.01.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 01/25/2020] [Indexed: 01/04/2023]
Abstract
Clinical decision-making for surgical repair of abdominal aortic aneurysms based on maximum aortic diameter presents limitations as rupture can occur below threshold for some aneurysms, whereas others are stable at large sizes. The proposed approach combines hemodynamics and geometric indices with in vivo deformation analysis to assess local weakening of the aortic wall for a case of impending rupture that was confirmed during open surgical repair. A new combined index, the Regional Rupture Potential, is introduced to help the assessment of individual aneurysms and their rupture risk, providing a rationale for clinical decisions.
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28
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Magnetic resonance imaging assessment of proteolytic enzyme concentrations and biologic properties of intraluminal thrombus in abdominal aortic aneurysms. J Vasc Surg 2020; 72:1025-1034. [PMID: 32067878 DOI: 10.1016/j.jvs.2019.11.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 11/04/2019] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The aim of the study was to determine whether magnetic resonance imaging (MRI) can be used in assessment of biologic activity of intraluminal thrombus (ILT) and proteolytic processes of the abdominal aortic aneurysm wall. METHODS Using MRI, 50 patients with asymptomatic infrarenal abdominal aortic aneurysm were analyzed at the maximum aneurysm diameter on T1-weighted images in the arterial phase after administration of contrast material. Relative ILT signal intensity (SI) was determined as the ratio between ILT SI and psoas muscle SI. During surgery, the full thickness of the ILT and the adjacent part of the aneurysm wall were harvested at the maximal diameter for biochemical analysis. The concentrations of matrix metalloproteinase 9 and neutrophil elastase (NE/ELA) were analyzed in harvested thrombi, and the concentrations of collagen type III, elastin, and proteoglycans were analyzed in harvested aneurysm walls. RESULTS A significant positive correlation was found between the NE/ELA concentration of the ILT and the relative SI (ρ = 0.309; P = .029). Furthermore, a negative correlation was observed between the elastin content of the aneurysm wall and the relative SI (ρ = -0.300; P = .034). No correlations were found between relative SI and concentration of matrix metalloproteinase 9, NE/ELA, collagen type III, or proteoglycan 4 in the aneurysm wall. CONCLUSIONS These findings indicate a potential novel use of MRI in prediction of thrombus proteolytic enzyme concentrations and the extracellular matrix content of the aneurysm wall, thus providing additional information for the risk of potential aneurysm rupture.
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29
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Zhu C, Leach JR, Wang Y, Gasper W, Saloner D, Hope MD. Intraluminal Thrombus Predicts Rapid Growth of Abdominal Aortic Aneurysms. Radiology 2020; 294:707-713. [PMID: 31990263 DOI: 10.1148/radiol.2020191723] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Background Intraluminal thrombus (ILT) within abdominal aortic aneurysms (AAAs) may be a potential marker for subsequent aneurysm growth. Purpose To investigate the role of ILT in AAA progression as assessed with CT and MRI. Materials and Methods This was a retrospective study, with patient data included from January 2004 to December 2018 at a Veteran Affairs medical center. Male patients with AAA who underwent contrast material-enhanced CT at baseline and CT or black-blood MRI at follow-up (minimal follow-up duration of 6 months) were included. The maximal AAA diameter was measured with multiplanar reconstruction, and the annual growth rate of aneurysms was calculated. Uni- and multivariable linear regression analyses were used to determine the relationship between demographic and imaging factors and aneurysm growth. Results A total of 225 patients (mean age, 72 years ± 9 [standard deviation]) were followed for a mean of 3.3 years ± 2.5. A total of 207 patients were followed up with CT, and 18 were followed up with MRI. At baseline, the median size of the AAA was 3.8 cm (interquartile range [IQR], 3.3-4.3 cm); 127 of 225 patients (54.7%) had ILT. When compared with AAAs without ILT, AAAs with ILT had larger baseline diameters (median, 4.1 cm [IQR, 3.6-4.8 cm] vs 3.4 cm [IQR, 3.2-3.9 cm]; P < .001) and faster growth rates (median, 2.0 mm/y [IQR, 1.3-3.2 mm/y] vs 1.0 mm/y [IQR, 0.4-1.8 mm/y]; P < .001). Small AAAs (size range, 3-4 cm) with ILT grew 1.9-fold faster than did those without ILT (median, 1.5 mm/y [IQR, 0.9-2.7 mm/y] vs 0.8 mm/y [IQR, 0.3-1.5 mm/y]; P < .001). Medium AAAs (size range, 4-5 cm) with ILT had 1.2-fold faster growth than did those without ILT (median growth, 2.1 mm/y [IQR, 1.4, 3.7 mm/y] vs 1.8 mm/y [IQR, 0.9, 2.0 mm/y]; P = .06). In multivariable analysis, baseline diameter and ILT were independently positively related to aneurysm growth rate (standardized regression coefficient, 0.43 [P < .001] and 0.15 [P = .02], respectively). Conclusion Both maximal cross-sectional aneurysm diameter and the presence of intraluminal thrombus are independent predictors of abdominal aortic aneurysm growth. © RSNA, 2020 Online supplemental material is available for this article.
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Affiliation(s)
- Chengcheng Zhu
- From the Departments of Radiology and Biomedical Imaging (C.Z., J.R.L., D.S., M.D.H.) and Surgery (W.G.), University of California, San Francisco, 4150 Clement St, San Francisco, CA 94121; and Department of Radiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China (Y.W.)
| | - Joseph R Leach
- From the Departments of Radiology and Biomedical Imaging (C.Z., J.R.L., D.S., M.D.H.) and Surgery (W.G.), University of California, San Francisco, 4150 Clement St, San Francisco, CA 94121; and Department of Radiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China (Y.W.)
| | - Yuting Wang
- From the Departments of Radiology and Biomedical Imaging (C.Z., J.R.L., D.S., M.D.H.) and Surgery (W.G.), University of California, San Francisco, 4150 Clement St, San Francisco, CA 94121; and Department of Radiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China (Y.W.)
| | - Warren Gasper
- From the Departments of Radiology and Biomedical Imaging (C.Z., J.R.L., D.S., M.D.H.) and Surgery (W.G.), University of California, San Francisco, 4150 Clement St, San Francisco, CA 94121; and Department of Radiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China (Y.W.)
| | - David Saloner
- From the Departments of Radiology and Biomedical Imaging (C.Z., J.R.L., D.S., M.D.H.) and Surgery (W.G.), University of California, San Francisco, 4150 Clement St, San Francisco, CA 94121; and Department of Radiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China (Y.W.)
| | - Michael D Hope
- From the Departments of Radiology and Biomedical Imaging (C.Z., J.R.L., D.S., M.D.H.) and Surgery (W.G.), University of California, San Francisco, 4150 Clement St, San Francisco, CA 94121; and Department of Radiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China (Y.W.)
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30
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Aortic sac enlargement after endovascular aneurysm repair: volume-related changes and the impact of intraluminal thrombus. Pol J Radiol 2019; 84:e530-e536. [PMID: 32082451 PMCID: PMC7016495 DOI: 10.5114/pjr.2019.91260] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 11/06/2019] [Indexed: 11/17/2022] Open
Abstract
Purpose Abdominal aortic aneurysm (AAA) growth after endovascular aneurysm repair (EVAR) is still unpredictable. The issue of optimal frequency of computed tomography angiography for surveillance and its measurement method accuracy remain unclear. We aimed to assess the value of abdominal aneurysm sac volume measurement for detecting expansions and the association of preprocedural intraluminal thrombus (ILT) volume with aneurysm sac growth following EVAR. Material and methods A total of 107 patients underwent elective EVAR. Inclusion criteria provided a cohort of 39 patients. Changes of postoperative maximum aneurysm sac diameter and AAA volume were calculated. Volumetric AAA changes and demographic data of the cases with clinically irrelevant AAA diameter enlargement were evaluated. Preoperative ILT volumes were collected. ILT and AAA sac volume ratio was calculated. Statistical data analysis was performed using standard methods. Results The mean changes of maximum AAA diameter and volume in percentage after EVAR were –5.08 ± 8.20 mm and –13.39 ± 23.32%, respectively. A moderate positive linear correlation between those changes was found (R2 = 0.731; p < 0.0001). The mean relative AAA volume increase in cases without clinically relevant diameter enlargement was 11.50 ± 8.27%. The means of ILT and AAA sac ratios were 0.59 ± 0.17 and 0.52 ± 1.8 in growing AAA sac and in stable or shrinking AAA sac groups, respectively (p = 0.308). Conclusions Volumetric AAA measurement may be useful as an additional method to diameter measurement after EVAR to identify clinically relevant sac growth. Preoperative volume of ILT may not significantly affect the growth rate of AAA after EVAR.
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31
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Skrebūnas A, Lengvenis G, Builytė IU, Žulpaitė R, Bliūdžius R, Purlys P, Baltrūnas T, Misonis N, Matačiūnas M, Marinskis G, Vajauskas D. Is Abdominal Aortic Aneurysm Behavior after Endovascular Repair Associated with Aneurysm Wall Density on Computed Tomography Angiography? ACTA ACUST UNITED AC 2019; 55:medicina55080406. [PMID: 31349723 PMCID: PMC6723564 DOI: 10.3390/medicina55080406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/07/2019] [Accepted: 07/19/2019] [Indexed: 11/26/2022]
Abstract
Background and objectives: Abdominal aortic aneurysm (AAA) growth is unpredictable after the endovascular aneurysm repair (EVAR). Continuing aortic wall degradation and weakening due to hypoxia may have a role in post-EVAR aneurysm sac growth. We aimed to assess the association of aortic wall density on computed tomography angiography (CTA) with aneurysm growth following EVAR. Materials and Methods: A total of 78 patients were included in the study. The control group consisted of 39 randomly assigned patients without aortic pathology. Post-EVAR aneurysm sac volumes on CTA were measured twice during the follow-up period to estimate aneurysm sac behavior. A maximum AAA sac diameter, aortic wall and lumen densities in Hounsfield units (HU) on CTA were measured. A relative aortic wall density (the ratio of aortic wall to lumen densities) was calculated. A statistical data analysis was performed using standard methods. Results: An increase in the AAA sac volume was observed in 12 (30.8%) cases. Median relative aortic wall density on CTA scores in both the patient and the control group at the level of the diaphragm were similar: 0.15 (interquartile range (IQR), 0.11–0.18) and 0.16 (IQR 0.11–0.18), p = 0.5378, respectively. The median (IQR) relative aortic wall density score at the level of the maximum AAA diameter in the patient group was lower than at the level below renal arteries in the control group: 0.10 (0.07–0.12) and 0.17 (0.12–0.23), p < 0.0001, respectively. The median (IQR) relative growing AAA sac wall density score was lower than a relative stable/shrinking AAA sac wall density score: 0.09 (0.06–0.10) and 0.11 (0.09–0.13), p = 0.0096, respectively. Conclusions: A lower aortic aneurysm wall density on CTA may be associated with AAA growth after EVAR.
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Affiliation(s)
- Arminas Skrebūnas
- Clinic of Cardiovascular Diseases, Faculty of Medicine, Vilnius University, 01513 Vilnius, Lithuania.
- Centre of Cardiology and Angiology, Vilnius University Hospital Santaros Klinikos, 08410 Vilnius, Lithuania.
| | - Givi Lengvenis
- Clinic of Cardiovascular Diseases, Faculty of Medicine, Vilnius University, 01513 Vilnius, Lithuania
| | - Inga Urtė Builytė
- Clinic of Cardiovascular Diseases, Faculty of Medicine, Vilnius University, 01513 Vilnius, Lithuania
| | - Rūta Žulpaitė
- Clinic of Cardiovascular Diseases, Faculty of Medicine, Vilnius University, 01513 Vilnius, Lithuania
| | - Rytis Bliūdžius
- Clinic of Cardiovascular Diseases, Faculty of Medicine, Vilnius University, 01513 Vilnius, Lithuania
| | - Petras Purlys
- Clinic of Cardiovascular Diseases, Faculty of Medicine, Vilnius University, 01513 Vilnius, Lithuania
| | - Tomas Baltrūnas
- Clinic of Cardiovascular Diseases, Faculty of Medicine, Vilnius University, 01513 Vilnius, Lithuania
- Centre of Cardiology and Angiology, Vilnius University Hospital Santaros Klinikos, 08410 Vilnius, Lithuania
| | - Nerijus Misonis
- Clinic of Cardiovascular Diseases, Faculty of Medicine, Vilnius University, 01513 Vilnius, Lithuania
- Centre of Cardiology and Angiology, Vilnius University Hospital Santaros Klinikos, 08410 Vilnius, Lithuania
| | - Mindaugas Matačiūnas
- Centre of Radiology and Nuclear Medicine, Vilnius University Hospital Santaros Klinikos, 08410 Vilnius, Lithuania
| | - Germanas Marinskis
- Clinic of Cardiovascular Diseases, Faculty of Medicine, Vilnius University, 01513 Vilnius, Lithuania
- Centre of Cardiology and Angiology, Vilnius University Hospital Santaros Klinikos, 08410 Vilnius, Lithuania
| | - Donatas Vajauskas
- Department of Radiology, Medical Academy, Lithuanian University of Health Sciences, 44307 Kaunas, Lithuania
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32
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Leach J, Kao E, Zhu C, Saloner D, Hope MD. On the relative impact of intraluminal thrombus heterogeneity on abdominal aortic aneurysm mechanics. J Biomech Eng 2019; 141:2737715. [PMID: 31253989 DOI: 10.1115/1.4044143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Indexed: 01/31/2023]
Abstract
Intraluminal thrombus (ILT) is present in the majority of abdominal aortic aneurysms (AAA) of a size warranting consideration for surgical or endovascular intervention. The rupture risk of AAAs is thought to be related to the balance of vessel wall strength and the mechanical stress caused by systemic blood pressure. Previous finite element analyses of AAAs have shown that ILT can reduce and homogenize aneurysm wall stress. These works have largely considered ILT to be homogeneous in mechanical character or have idealized a stiffness distribution through the thrombus thickness. In this work, we use MRI to delineate the heterogeneous composition of ILT in 7 AAAs and perform patient-specific finite element analysis under multiple conditions of ILT layer stiffness disparity. We find that explicit incorporation of ILT heterogeneity in the finite element analysis is unlikely to substantially alter major stress analysis predictions regarding aneurysm rupture risk in comparison to models assuming a homogenous thrombus, provided that the maximal ILT stiffness is the same between models. Our results also show that under a homogeneous ILT assumption, the choice of ILT stiffness from values common in the literature can result in significantly larger variations in stress predictions compared to the effects of thrombus heterogeneity.
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Affiliation(s)
- Joseph Leach
- University of California, San Francisco, Department of Radiology and Biomedical Imaging, 513 Parnassus Ave, Suite S-261, Box 0628, San Francisco, CA 94143
| | - Evan Kao
- University of California, San Francisco, Department of Radiology and Biomedical Imaging, San Francisco, CA 94143
| | - Chengcheng Zhu
- University of California, San Francisco, Department of Radiology and Biomedical Imaging, San Francisco, CA 94143
| | - David Saloner
- University of California, San Francisco, Department of Radiology and Biomedical Imaging, San Francisco, CA 94143
| | - Michael D Hope
- University of California, San Francisco, Department of Radiology and Biomedical Imaging, San Francisco, CA 94143
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Cebull HL, Soepriatna AH, Boyle JJ, Rothenberger SM, Goergen CJ. Strain Mapping From Four-Dimensional Ultrasound Reveals Complex Remodeling in Dissecting Murine Abdominal Aortic Aneurysms. J Biomech Eng 2019; 141:2728066. [DOI: 10.1115/1.4043075] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Indexed: 12/12/2022]
Abstract
Current in vivo abdominal aortic aneurysm (AAA) imaging approaches tend to focus on maximum diameter but do not measure three-dimensional (3D) vascular deformation or strain. Complex vessel geometries, heterogeneous wall compositions, and surrounding structures can all influence aortic strain. Improved understanding of complex aortic kinematics has the potential to increase our ability to predict aneurysm expansion and eventual rupture. Here, we describe a method that combines four-dimensional (4D) ultrasound and direct deformation estimation to compute in vivo 3D Green-Lagrange strain in murine angiotensin II-induced suprarenal dissecting aortic aneurysms, a commonly used small animal model. We compared heterogeneous patterns of the maximum, first-component 3D Green-Lagrange strain with vessel composition from mice with varying AAA morphologies. Intramural thrombus and focal breakage in the medial elastin significantly reduced aortic strain. Interestingly, a dissection that was not detected with high-frequency ultrasound also experienced reduced strain, suggesting medial elastin breakage that was later confirmed via histology. These results suggest that in vivo measurements of 3D strain can provide improved insight into aneurysm disease progression. While further work is needed with both preclinical animal models and human imaging studies, this initial murine study indicates that vessel strain should be considered when developing an improved metric for predicting aneurysm growth and rupture.
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Affiliation(s)
- Hannah L. Cebull
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Arvin H. Soepriatna
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - John J. Boyle
- Department of Biomedical Engineering, Washington University, 1 Brookings Drive, St Louis, MO 63130
- Department of Orthopaedic Surgery, Columbia University, 116th Street and Broadway, New York, NY 10027 e-mail:
| | - Sean M. Rothenberger
- Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
| | - Craig J. Goergen
- Mem. ASME Weldon School of Biomedical Engineering, Purdue University, 206 S. Martin Jischke Drive, West Lafayette, IN 47907 e-mail:
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Zhu C, Leach JR, Tian B, Cao L, Wen Z, Wang Y, Liu X, Liu Q, Lu J, Saloner D, Hope MD. Evaluation of the distribution and progression of intraluminal thrombus in abdominal aortic aneurysms using high-resolution MRI. J Magn Reson Imaging 2019; 50:994-1001. [PMID: 30694008 DOI: 10.1002/jmri.26676] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/16/2019] [Accepted: 01/17/2019] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Intraluminal thrombus (ILT) signal intensity on MRI has been studied as a potential marker of abdominal aortic aneurysm (AAA) progression. PURPOSE 1) To characterize the relationship between ILT signal intensity and AAA diameter; 2) to evaluate ILT change over time; and 3) to assess the relationship between ILT features and AAA growth. STUDY TYPE Prospective. SUBJECTS Eighty AAA patients were imaged, and a subset (n = 41) were followed with repeated MRI for 16 ± 9 months. FIELD STRENGTH/SEQUENCE 3D black-blood fast-spin-echo sequence at 3 T. ASSESSMENT ILT was designated as "bright" if the signal was greater than 1.2 times that of adjacent psoas muscle. AAAs were divided into three groups based on ILT: Type 1: bright ILT; Type 2: isointense ILT; Type 3: no ILT. During follow-up, an active ILT change was defined as new ILT formation or an increase in ILT signal intensity to bright; stable ILT was defined as no change in ILT type or ILT became isointense from bright previously. STATISTICAL TESTS Shapiro-Wilk test; Mann-Whitney U-test; Fisher's exact test; Kruskal-Wallis test; Spearman's r; intraclass correlation coefficient (ICC), Cohen's kappa. RESULTS AAAs with Type 1 ILT were larger than those with Types 2 and 3 ILT (5.1 ± 1.1 cm, 4.4 ± 0.9 cm, 4.2 ± 0.8 cm, P = 0.008). The growth rate of AAAs with Type 1 ILT was significantly greater than that of AAAs with Types 2 and 3 ILT (2.6 ± 2.5, 0.6 ± 1.3, 1.5 ± 0.6 mm/year, P = 0.01). During follow-up, AAAs with active ILT changes had a 3-fold increased growth rate compared with AAAs with stable ILT (3.6 ± 3.0 mm/year vs. 1.2 ± 1.5 mm/year, P = 0.008). DATA CONCLUSION AAAs with bright ILT are larger in diameter and grow faster. Active ILT change is associated with faster AAA growth. Black-blood MRI can characterize ILT features and monitor their change over time, which may provide new insights into AAA risk assessment. LEVEL OF EVIDENCE 2 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2019;50:994-1001.
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Affiliation(s)
- Chengcheng Zhu
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| | - Joseph R Leach
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| | - Bing Tian
- Department of Radiology, Changhai Hospital, Shanghai, China
| | - Lizhen Cao
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| | - Zhaoying Wen
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA.,Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Disease, Beijing, China
| | - Yan Wang
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| | - Xinke Liu
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA.,Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Qi Liu
- Department of Radiology, Changhai Hospital, Shanghai, China
| | - Jianping Lu
- Department of Radiology, Changhai Hospital, Shanghai, China
| | - David Saloner
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| | - Michael D Hope
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
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Cameron SJ, Russell HM, Owens AP. Antithrombotic therapy in abdominal aortic aneurysm: beneficial or detrimental? Blood 2018; 132:2619-2628. [PMID: 30228233 PMCID: PMC6302498 DOI: 10.1182/blood-2017-08-743237] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 09/10/2018] [Indexed: 12/13/2022] Open
Abstract
Abdominal aortic aneurysm (AAA) is a degenerative vascular pathology resulting in significant morbidity and mortality in older adults due to rupture and sudden death. Despite 150 000 new cases and nearly 15 000 deaths annually, the only approved treatment of AAA is surgical or endovascular intervention when the risk for aortic rupture is increased. The goal of the scientific community is to develop novel pharmaceutical treatment strategies to reduce the need for surgical intervention. Because most clinically relevant AAAs contain a complex structure of fibrin, inflammatory cells, platelets, and red blood cells in the aneurysmal sac known as an intraluminal thrombus (ILT), antithrombotic therapies have emerged as potential pharmaceutical agents for the treatment of AAA progression. However, the efficacy of these treatments has not been shown, and the effects of shrinking the ILT may be as detrimental as they are beneficial. This review discusses the prospect of anticoagulant and antiplatelet (termed collectively as antithrombotic) therapies in AAA. Herein, we discuss the role of the coagulation cascade and platelet activation in human and animal models of AAA, the composition of ILT in AAA, a possible role of the ILT in aneurysm stabilization, and the implications of antithrombotic drugs in AAA treatment.
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Affiliation(s)
- Scott J Cameron
- Department of Medicine (Cardiology) and
- Department of Surgery (Cardiac Surgery), University of Rochester School of Medicine, Rochester, NY; and
| | - Hannah M Russell
- Division of Cardiovascular Health and Disease and
- Pathobiology and Molecular Medicine, Department of Internal Medicine, The University of Cincinnati College of Medicine, Cincinnati, OH
| | - A Phillip Owens
- Division of Cardiovascular Health and Disease and
- Pathobiology and Molecular Medicine, Department of Internal Medicine, The University of Cincinnati College of Medicine, Cincinnati, OH
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36
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Strongly Coupled Morphological Features of Aortic Aneurysms Drive Intraluminal Thrombus. Sci Rep 2018; 8:13273. [PMID: 30185838 PMCID: PMC6125404 DOI: 10.1038/s41598-018-31637-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 08/15/2018] [Indexed: 01/13/2023] Open
Abstract
Over 75% of abdominal aortic aneurysms harbor an intraluminal thrombus, and increasing evidence suggests that biologically active thrombus contributes to the natural history of these potentially lethal lesions. Thrombus formation depends on the local hemodynamics, which in turn depends on morphological features of the aneurysm and near vasculature. We previously presented a hemodynamically motivated “thrombus formation potential” that predicts where and when thrombus might form. Herein, we combine detailed studies of the three-dimensional hemodynamics with methods of sparse grid collocation and interpolation via kriging to examine roles of five key morphological features of aneurysms on thrombus formation: lesion diameter, axial position, length, curvature, and renal artery position. Computational simulations suggest that maximum diameter is a key determinant of thrombogenicity, but other morphological features modulate this dependence. More distally located lesions tend to have a higher thrombus formation potential and shorter lesions tend to have a higher potential than longer lesions, given the same aneurysmal dilatation. Finally, movement of vortical structures through the infrarenal aorta and lesion can significantly affect thrombogenicity. Formation of intraluminal thrombus within an evolving abdominal aortic aneurysm thus depends on coupled morphological features, not all intuitive, and computational simulations can be useful for predicting thrombogenesis.
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Yazdani A, Li H, Bersi MR, Di Achille P, Insley J, Humphrey JD, Karniadakis GE. Data-driven Modeling of Hemodynamics and its Role on Thrombus Size and Shape in Aortic Dissections. Sci Rep 2018; 8:2515. [PMID: 29410467 PMCID: PMC5802786 DOI: 10.1038/s41598-018-20603-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 01/22/2018] [Indexed: 11/21/2022] Open
Abstract
Aortic dissection is a pathology that manifests due to microstructural defects in the aortic wall. Blood enters the damaged wall through an intimal tear, thereby creating a so-called false lumen and exposing the blood to thrombogenic intramural constituents such as collagen. The natural history of this acute vascular injury thus depends, in part, on thrombus formation, maturation, and possible healing within the false lumen. A key question is: Why do some false lumens thrombose completely while others thrombose partially or little at all? An ability to predict the location and extent of thrombus in subjects with dissection could contribute significantly to clinical decision-making, including interventional design. We develop, for the first time, a data-driven particle-continuum model for thrombus formation in a murine model of aortic dissection. In the proposed model, we simulate a final-value problem in lieu of the original initial-value problem with significantly fewer particles that may grow in size upon activation, thus representing the local concentration of blood-borne species. Numerical results confirm that geometry and local hemodynamics play significant roles in the acute progression of thrombus. Despite geometrical differences between murine and human dissections, mouse models can provide considerable insight and have gained popularity owing to their reproducibility. Our results for three classes of geometrically different false lumens show that thrombus forms and extends to a greater extent in regions with lower bulk shear rates. Dense thrombi are less likely to form in high-shear zones and in the presence of strong vortices. The present data-driven study suggests that the proposed model is robust and can be employed to assess thrombus formation in human aortic dissections.
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Affiliation(s)
- Alireza Yazdani
- Division of Applied Mathematics, Brown University, Providence, RI, 02912, USA.
| | - He Li
- Division of Applied Mathematics, Brown University, Providence, RI, 02912, USA
| | - Matthew R Bersi
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520, USA
| | - Paolo Di Achille
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520, USA
| | - Joseph Insley
- Argonne National Laboratory, Argonne, IL 60439; Northern Illinois University, DeKalb, IL, 60115, USA
| | - Jay D Humphrey
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520, USA
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38
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Common First-Pass CT Angiography Findings Associated With Rapid Growth Rate in Abdominal Aorta Aneurysms Between 3 and 5 cm in Largest Diameter. AJR Am J Roentgenol 2018; 210:431-437. [DOI: 10.2214/ajr.17.18094] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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39
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Flow stagnation volume and abdominal aortic aneurysm growth: Insights from patient-specific computational flow dynamics of Lagrangian-coherent structures. Comput Biol Med 2018; 92:98-109. [DOI: 10.1016/j.compbiomed.2017.10.033] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 10/09/2017] [Accepted: 10/28/2017] [Indexed: 12/23/2022]
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40
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Kemmerling EMC, Peattie RA. Abdominal Aortic Aneurysm Pathomechanics: Current Understanding and Future Directions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1097:157-179. [DOI: 10.1007/978-3-319-96445-4_8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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41
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Virag L, Wilson JS, Humphrey JD, Karšaj I. Potential biomechanical roles of risk factors in the evolution of thrombus-laden abdominal aortic aneurysms. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2017; 33:10.1002/cnm.2893. [PMID: 28447404 PMCID: PMC5658277 DOI: 10.1002/cnm.2893] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 02/23/2017] [Accepted: 04/23/2017] [Indexed: 05/22/2023]
Abstract
Abdominal aortic aneurysms (AAAs) typically harbour an intraluminal thrombus (ILT), yet most prior computational models neglect biochemomechanical effects of thrombus on lesion evolution. We recently proposed a growth and remodelling model of thrombus-laden AAAs that introduced a number of new constitutive relations and associated model parameters. Because values of several of these parameters have yet to be elucidated by clinical data and could vary significantly from patient to patient, the aim of this study was to investigate the possible extent to which these parameters influence AAA evolution. Given that some of these parameters model potential effects of factors that influence the risk of rupture, this study also provides insight into possible roles of common risk factors on the natural history of AAAs. Despite geometrical limitations of a cylindrical domain, findings support current thought that smoking, hypertension, and female sex likely increase the risk of rupture. Although thrombus thickness is not a reliable risk factor for rupture, the model suggests that the presence of ILT may have a destabilizing effect on AAA evolution, consistent with histological findings from human samples. Finally, simulations support two hypotheses that should be tested on patient-specific geometries in the future. First, ILT is a potential source of the staccato enlargement observed in many AAAs. Second, ILT can influence rupture risk, positively or negatively, via competing biomechanical (eg, stress shielding) and biochemical (ie, proteolytic) effects. Although further computational and experimental studies are needed, the present findings highlight the importance of considering ILT when predicting aneurysmal enlargement and rupture risk.
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Affiliation(s)
- Lana Virag
- Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Zagreb, Croatia
| | - John S. Wilson
- Department of Radiology, Emory University, Atlanta, GA, USA
| | - Jay D. Humphrey
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - Igor Karšaj
- Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Zagreb, Croatia
- Address for Correspondence: Igor Karšaj, Ph.D., Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Ivana Lučića 5, Zagreb, 10000, Croatia, Phone: +38516168125,
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42
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Lindquist Liljeqvist M, Hultgren R, Siika A, Gasser TC, Roy J. Gender, smoking, body size, and aneurysm geometry influence the biomechanical rupture risk of abdominal aortic aneurysms as estimated by finite element analysis. J Vasc Surg 2017; 65:1014-1021.e4. [PMID: 28342508 DOI: 10.1016/j.jvs.2016.10.074] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 10/14/2016] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Finite element analysis (FEA) has been suggested to be superior to maximal diameter measurements in predicting rupture of abdominal aortic aneurysms (AAAs). Our objective was to investigate to what extent previously described rupture risk factors were associated with FEA-estimated rupture risk. METHODS One hundred forty-six patients with an asymptomatic AAA of a 40- to 60-mm diameter were retrospectively identified and consecutively included. The patients' computed tomography angiograms were analyzed by FEA without (neutral) and with (specific) input of patient-specific mean arterial pressure (MAP), gender, family history, and age. The maximal wall stress/wall strength ratio was described as a rupture risk equivalent diameter (RRED), which translated this ratio into an average aneurysm diameter of corresponding rupture risk. RESULTS In multivariate linear regression, RREDneutral increased with female gender (3.7 mm; 95% confidence interval [CI], 0.13-7.3) and correlated with patient height (0.27 mm/cm; 95% CI, 0.11-0.43) and body surface area (BSA, 16 mm/m2; 95% CI, 8.3-24) and inversely with body mass index (BMI, -0.40 mm/kg m-2; 95% CI, -0.75 to -0.054) in a wall stress-dependent manner. Wall stress-adjusted RREDneutral was raised if the patient was currently smoking (1.1 mm; 95% CI, 0.21-1.9). Age, MAP, family history, and patient weight were unrelated to RREDneutral. In specific FEA, RREDspecific increased with female gender, MAP, family history positive for AAA, height, and BSA, whereas it was inversely related to BMI. All results were independent of aneurysm diameter. Peak wall stress and RRED correlated with aneurysm diameter and lumen volume. CONCLUSIONS Female gender, current smoking, increased patient height and BSA, and low BMI were found to increase the mechanical rupture risk of AAAs. Previously described rupture risk factors may in part be explained by patient characteristic-dependent variations in aneurysm biomechanics.
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Affiliation(s)
| | - Rebecka Hultgren
- Vascular Surgery, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Antti Siika
- Vascular Surgery, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - T Christian Gasser
- Department of Solid Mechanics, School of Engineering Sciences, Royal Institute of Technology, Stockholm, Sweden
| | - Joy Roy
- Vascular Surgery, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
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Di Achille P, Tellides G, Humphrey J. Hemodynamics-driven deposition of intraluminal thrombus in abdominal aortic aneurysms. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2017; 33:10.1002/cnm.2828. [PMID: 27569676 PMCID: PMC5332472 DOI: 10.1002/cnm.2828] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 07/06/2016] [Accepted: 08/25/2016] [Indexed: 05/18/2023]
Abstract
Accumulating evidence suggests that intraluminal thrombus plays many roles in the natural history of abdominal aortic aneurysms. There is, therefore, a pressing need for computational models that can describe and predict the initiation and progression of thrombus in aneurysms. In this paper, we introduce a phenomenological metric for thrombus deposition potential and use hemodynamic simulations based on medical images from 6 patients to identify best-fit values of the 2 key model parameters. We then introduce a shape optimization method to predict the associated radial growth of the thrombus into the lumen based on the expectation that thrombus initiation will create a thrombogenic surface, which in turn will promote growth until increasing hemodynamically induced frictional forces prevent any further cell or protein deposition. Comparisons between predicted and actual intraluminal thrombus in the 6 patient-specific aneurysms suggest that this phenomenological description provides a good first estimate of thrombus deposition. We submit further that, because the biologically active region of the thrombus appears to be confined to a thin luminal layer, predictions of morphology alone may be sufficient to inform fluid-solid-growth models of aneurysmal growth and remodeling.
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Affiliation(s)
- P. Di Achille
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - G. Tellides
- Department of Surgery, Yale School of Medicine, New Haven, CT, USA
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - J.D. Humphrey
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
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44
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van Noort K, Schuurmann RC, Wermelink B, Slump CH, Kuijpers KC, de Vries JPP. Fluid displacement from intraluminal thrombus of abdominal aortic aneurysm as a result of uniform compression. Vascular 2017; 25:542-548. [PMID: 28441922 DOI: 10.1177/1708538117707612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Objectives The results after aneurysm repair with an endovascular aneurysm sealing (EVAS) system are dependent on the stability of the aneurysm sac and particularly the intraluminal abdominal aortic thrombus (ILT). The postprocedural ILT volume is decreased compared with preprocedural ILT volume in aortic aneurysm patients treated with EVAS. We hypothesize that ILT is not stable in all patients and pressurization of the ILT may result in displacement of fluids from the ILT, no differently than serum is displaced from whole blood when it settles. To date, the mechanism and quantification of fluid displacement from ILT are unknown. Methods The study included 21 patients who underwent elective open abdominal aortic aneurysm repair. The ILT was harvested as a routine procedure during the operation. After excision of a histologic sample of the ILT specimen in four patients, ILT volume was measured and the ILT was compressed in a dedicated compression setup designed to apply uniform compression of 200 mmHg for 5 min. After compression, the volumes of the remaining thrombus and the displaced fluid were measured. Results The median (interquartile-range) of ILT volume before compression was 60 (66) mL, and a median of 5.7 (8.4) mL of fluid was displaced from the ILT after compression, resulting in a median thrombus volume decrease of 11% (10%). Fluid components can be up to 31% of the entire ILT volume. Histologic examination of four ILT specimens showed a reduction of the medial layer of the ILT after compression, which was the result of compression of fluid-containing canaliculi. Conclusions Applying pressure of 200 mmHg to abdominal aortic aneurysm ILT resulted in the displacement of fluid, with a large variation among patients. Fluid displacement may result in decrease of ILT volume during and after EVAS, which might have implications on pre-EVAS volume planning and on stability of the endobags during follow-up which may lead to migration, endoleak or both.
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Affiliation(s)
- Kim van Noort
- 1 Department of Vascular Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands.,2 Technical Medicine, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Richte Cl Schuurmann
- 1 Department of Vascular Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands.,2 Technical Medicine, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Bryan Wermelink
- 1 Department of Vascular Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands.,2 Technical Medicine, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - Cornelis H Slump
- 3 MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Karel C Kuijpers
- 4 Department of Pathology, St. Antonius Hospital, Nieuwegein, The Netherlands
| | - Jean-Paul Pm de Vries
- 1 Department of Vascular Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands
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Correlation of Wall Microstructure and Heterogeneous Distributions of Strain in Evolving Murine Abdominal Aortic Aneurysms. Cardiovasc Eng Technol 2017; 8:193-204. [PMID: 28378165 DOI: 10.1007/s13239-017-0301-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 03/20/2017] [Indexed: 10/19/2022]
Abstract
A primary deficiency in predicting the progression and rupture-risk of abdominal aortic aneurysms (AAAs) is an inability to assign patient-specific, heterogeneous biomechanical properties to the remodelling aortic wall. Toward this end, we investigated possible correlations between three quantities having the potential for non-invasive measurement (diameter, wall thickness, and strain) and local wall microstructure within evolving experimental AAAs. AAAs were initiated in male C57BL/6J mice via in situ adventitial application of elastase and allowed to progress for 1-4 weeks. Regional in vitro Green strain was assessed using custom panoramic digital image correlation and compared to local geometry and histology. Diameter correlated mildly with elastin grade and collagen, when considering all circumferential locations and remodeling times. Normalized wall thickness correlated strongly with normalized collagen area fraction, though with outliers in highly cellular regions. Circumferential Green strain correlated strongly with elastin grade when measured over the range of 20-140 mmHg, though the correlation weakened across a physiologic range of 80-120 mmHg. Axial strain correlated strongly between in vitro and physiologic ranges of pressures. Circumferential heterogeneities render diameter a poor predictor of underlying regional microstructure. Thickness may indicate collagen content, though corrections are needed in regions of increased cellularity. In vitro circumferential strain predicts local functional elastin over large ranges of pressure, but there is a need to extend this correlation to clinically relevant pressures. Axial strain in the aneurysmal shoulder region may reflect the elastic integrity within the apical region of the lesion and should be explored as an indicator of disease severity.
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46
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Yeon JH, Mazinani N, Schlappi TS, Chan KYT, Baylis JR, Smith SA, Donovan AJ, Kudela D, Stucky GD, Liu Y, Morrissey JH, Kastrup CJ. Localization of Short-Chain Polyphosphate Enhances its Ability to Clot Flowing Blood Plasma. Sci Rep 2017; 7:42119. [PMID: 28186112 PMCID: PMC5301195 DOI: 10.1038/srep42119] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 01/04/2017] [Indexed: 11/09/2022] Open
Abstract
Short-chain polyphosphate (polyP) is released from platelets upon platelet activation, but it is not clear if it contributes to thrombosis. PolyP has increased propensity to clot blood with increased polymer length and when localized onto particles, but it is unknown whether spatial localization of short-chain polyP can accelerate clotting of flowing blood. Here, numerical simulations predicted the effect of localization of polyP on clotting under flow, and this was tested in vitro using microfluidics. Synthetic polyP was more effective at triggering clotting of flowing blood plasma when localized on a surface than when solubilized in solution or when localized as nanoparticles, accelerating clotting at 10-200 fold lower concentrations, particularly at low to sub-physiological shear rates typical of where thrombosis occurs in large veins or valves. Thus, sub-micromolar concentrations of short-chain polyP can accelerate clotting of flowing blood plasma under flow at low to sub-physiological shear rates. However, a physiological mechanism for the localization of polyP to platelet or vascular surfaces remains unknown.
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Affiliation(s)
- Ju Hun Yeon
- Michael Smith Laboratories and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Nima Mazinani
- Michael Smith Laboratories and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Travis S Schlappi
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Karen Y T Chan
- Michael Smith Laboratories and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - James R Baylis
- Michael Smith Laboratories and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Stephanie A Smith
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Alexander J Donovan
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Damien Kudela
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
| | - Galen D Stucky
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
| | - Ying Liu
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL, USA
| | - James H Morrissey
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Christian J Kastrup
- Michael Smith Laboratories and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
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A General Shear-Dependent Model for Thrombus Formation. PLoS Comput Biol 2017; 13:e1005291. [PMID: 28095402 PMCID: PMC5240924 DOI: 10.1371/journal.pcbi.1005291] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 12/07/2016] [Indexed: 01/03/2023] Open
Abstract
Modeling the transport, activation, and adhesion of platelets is crucial in predicting thrombus formation and growth following a thrombotic event in normal or pathological conditions. We propose a shear-dependent platelet adhesive model based on the Morse potential that is calibrated by existing invivo and invitro experimental data and can be used over a wide range of flow shear rates ( 100<γ˙<28,000s-1). We introduce an Eulerian-Lagrangian model where hemodynamics is solved on a fixed Eulerian grid, while platelets are tracked using a Lagrangian framework. A force coupling method is introduced for bidirectional coupling of platelet motion with blood flow. Further, we couple the calibrated platelet aggregation model with a tissue-factor/contact pathway coagulation cascade, representing the relevant biology of thrombin generation and the subsequent fibrin deposition. The range of shear rates covered by the proposed model encompass venous and arterial thrombosis, ranging from low-shear-rate conditions in abdominal aortic aneurysms and thoracic aortic dissections to thrombosis in stenotic arteries following plaque rupture, where local shear rates are extremely high. Hemostasis (thrombus formation) is the normal physiological response that prevents significant blood loss after vascular injury. The resulting clots can form under different flow conditions in the veins as well as the arteries. The excessive and undesirable formation of clots (i.e., thrombosis) in our circulatory system may lead to significant morbidity and mortality. Some of these pathologies are deep vein thrombosis and pulmonary embolism and atherothrombosis (thrombosis triggered by plaque rupture) in coronary arteries, to name a few. The process of clot formation and growth at a site on a blood vessel wall involves a number of simultaneous processes including: multiple chemical reactions in the coagulation cascade, species transport and platelet adhesion all of which are strongly influenced by the hydrodynamic forces. Numerical models for blood clotting normally focus on one of the processes under a specific flow condition. Here, we propose a general numerical model that encompass a wide range of hemodynamic conditions in the veins and arteries, with individual platelets and their adhesive dynamics included explicitly in the models. Further, we include the biochemistry of coagulation cascade, which is essential to modeling thrombus formation, and couple that to our platelet aggregation model. The simulation results—tested against three different experiments—demonstrate that the proposed model is effective in capturing the invivo and invitro experimental observations.
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Arzani A, Gambaruto AM, Chen G, Shadden SC. Wall shear stress exposure time: a Lagrangian measure of near-wall stagnation and concentration in cardiovascular flows. Biomech Model Mechanobiol 2016; 16:787-803. [DOI: 10.1007/s10237-016-0853-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 11/08/2016] [Indexed: 12/18/2022]
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Nandlall SD, Konofagou EE. Assessing the Stability of Aortic Aneurysms with Pulse Wave Imaging. Radiology 2016; 281:772-781. [PMID: 27276242 DOI: 10.1148/radiol.2016151407] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Purpose To assess whether the stability of murine aortic aneurysms is associated with the homogeneity of pulse wave propagation within the saccular wall. Materials and Methods All animal procedures were approved by the institutional Animal Care and Use Committee. Apolipoprotein E and tissue inhibitor of metalloproteinases-1 knockout mice (n = 26) were infused with angiotensin II by using subcutaneously implanted osmotic pumps, with an additional control mouse used for histologic examination (n = 1). Pulse wave imaging (PWI) was performed just before infusion and 15 days after infusion by using 40-MHz ultrasonography at 8000 frames per second (with electrocardiographic gating). Aneurysm appearance on B-mode images was monitored every 2-3 days for 30 days. On the basis of B-mode images obtained after 30 days, aneurysms were deemed to have been unstable if they had ruptured; otherwise, they were deemed stable. Statistical significance was assessed by using two-tailed t tests. Results In normal aortas, the pulse waves propagated at relatively constant velocities (mean ± standard deviation, 2.8 m/sec ± 0.9). Fifteen days after infusion, all mice had developed aneurysms, with significant (P < .001/12) changes in maximum anterior-posterior diameter (increase of 54.9% ± 2.5) and pulse wave velocity (PWV) (decrease of 1.3 m/sec ± 0.8). While there was no significant difference in these parameters (P = .45 for diameter and P = .55 for PWV) between stable aneurysms (n = 12) and unstable aneurysms (n = 14), the standard deviation of the high-resolution PWV was significantly higher (P < .001/12) in unstable aneurysms (5.7 m/sec ± 1.6) than in stable ones (3.2 m/sec ± 0.9). Conclusion High-resolution PWI was used to measure the local homogeneity of pulse wave propagation within the saccular wall, which is lower in unstable aneurysms than in stable ones. Hence, if proven to add additional information beyond size and appearance in human studies, PWI could potentially be used to assess the stability of aneurysms by providing information that is complementary to the anatomic data obtained with conventional B-mode imaging. © RSNA, 2016 Online supplemental material is available for this article.
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Affiliation(s)
- Sacha D Nandlall
- From the Departments of Biomedical Engineering (S.D.N., E.E.K.) and Radiology (E.E.K.), Columbia University, 1210 Amsterdam Ave, ET 351, MC 8904, New York, NY 10027
| | - Elisa E Konofagou
- From the Departments of Biomedical Engineering (S.D.N., E.E.K.) and Radiology (E.E.K.), Columbia University, 1210 Amsterdam Ave, ET 351, MC 8904, New York, NY 10027
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Boersen J, Schuurmann R, Slump C, van den Heuvel D, Reijnen M, ter Mors T, Vahl A, de Vries J. Changes in Aortoiliac Anatomy After Elective Treatment of Infrarenal Abdominal Aortic Aneurysms with a Sac Anchoring Endoprosthesis. Eur J Vasc Endovasc Surg 2016; 51:56-62. [DOI: 10.1016/j.ejvs.2015.08.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 08/23/2015] [Indexed: 01/10/2023]
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