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Han Q, Qiao L, Yin L, Sui X, Shao W, Wang Q. The effect of exercise training intervention for patients with abdominal aortic aneurysm on cardiovascular and cardiorespiratory variables: an updated meta-analysis of randomized controlled trials. BMC Cardiovasc Disord 2024; 24:80. [PMID: 38291355 PMCID: PMC10829311 DOI: 10.1186/s12872-024-03745-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 01/22/2024] [Indexed: 02/01/2024] Open
Abstract
OBJECTIVE The purpose of this meta-analysis was to evaluate the effect of exercise training intervention in patients with abdominal aortic aneurysm (AAA). METHODS Eight randomized controlled trials (RCTs) that recruited 588 AAA patients were extracted using 4 databases (PubMed, Embase, Wanfang Data, and Cochrane Library). Physiological and biochemistry parameters that included in this study are high-sensitivity C-reactive protein (hs-CRP), respiratory peak oxygen uptake rate (VO2peak), triglyceride (TG), total cholesterol (TC), anaerobic threshold (AT), the diameter of AAA, high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), and matrix metalloproteinase-9 (MMP-9). Standard mean difference (SMD) was used to assess the between group effect. RESULTS This meta-analysis was synthesized with findings from RCTs and found that hs-CRP (SMD, - 0.56 mg/dL; 95% CI: - 0.90 to 0.22; P = 0.001), VO2peak (SMD, 0.4 mL/kg/min; 95% CI, 0.21 to 0.60; P < 0.001), TG (SMD, - 0.39 mg/dL; 95% CI: - 0.02 to 0.77; P = 0.04), and AT (SMD, 0.75 mL/kg/min; 95% CI, 0.54 to 0.96; P < 0.001) were significantly improved in the exercise groups, while the size of AAA (SMD, - 0.15; 95% CI: - 0.36 to 0.06; P = 0.15), TC (SMD, 0.16 mg/dL; 95% CI: - 0.10 to 0.42; P = 0.23), HDL/LDL ratio (SMD, - 0.06; 95% CI: - 0.32 to 0.20; P = 0.64), HDL (SMD, - 0.09; 95% CI: - 0.39 to 0.20; P = 0.54), LDL (SMD, 0.08; 95% CI: - 0.21 to 0.38; P = 0.59), and MMP-9 (SMD, - 0.23 mg/dL; 95% CI: - 0.53 to 0.06; P = 0.12) did not differ in the exercise groups compared with the controls. CONCLUSION Exercise intervention improved some of the CVD risk factors but not all, hs-CRP, VO2peak and AT were significantly improved after exercise intervention, while, changes of MMP-9, the size of AAA, and the overall lipids profile were not. Exercise intervention provides an additional solution for improving cardiorespiratory capacity and health status among AAA patients, and might lead to a delay of AAA progression.
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Affiliation(s)
- Qi Han
- Sports Nutrition Center, National Institute of Sports Medicine, Beijing, 100029, China
- Beijing Sport University, Beijing, 100084, China
| | - Li Qiao
- Beijing Competitor Sports Nutrition Research Institute, Beijing, 100029, China
| | - Li Yin
- Department of Vascular Surgery, The Second Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou, 310020, China
- Department of Surgery, Northwestern University, Chicago, IL, 60611, USA
| | - Xuemei Sui
- Department of Exercise Science, Arnold School of Public Health, University of South Carolina, Columbia, SC, 29208, USA
| | - Wenjuan Shao
- Beijing Sport University, Beijing, 100084, China
- Minzu University of China, Beijing, 100081, China
| | - Qirong Wang
- Sports Nutrition Center, National Institute of Sports Medicine, Beijing, 100029, China.
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Tang X, Wu C. A predictive surrogate model for hemodynamics and structural prediction in abdominal aorta for different physiological conditions. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2024; 243:107931. [PMID: 37992570 DOI: 10.1016/j.cmpb.2023.107931] [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: 10/30/2023] [Revised: 11/12/2023] [Accepted: 11/14/2023] [Indexed: 11/24/2023]
Abstract
BACKGROUND AND OBJECTIVE This study investigates the application of a Predictive Surrogate Model (PSM) for the prediction of the fluid and solid variables in the abdominal aorta by integrating Proper Orthogonal Decomposition (POD) and Long Short-Term Memory (LSTM) techniques. METHODS The Fluid-Structure Interaction (FSI) solver, which serves as the Full-Order Model (FOM), can capture the blood hemodynamics and structural mechanics precisely for a variety of physiological states, namely the rest and exercise conditions. RESULTS Detailed analyses have been conducted on velocity components, pressure, Wall Shear Stress (WSS), and Oscillatory Shear Index (OSI) variables. Firstly, the reconstruction error has been derived based on a specific number of POD bases to assess the Reduced Order Model (ROM). Notably, the reconstruction error for velocity components in the rest condition is one order of magnitude higher than that in the exercise condition, yet both remained below 10%. This error for pressure is even more minimal, being less than 1%. CONCLUSIONS The PSM is evaluated against rest and exercise conditions, exhibiting promising results despite the inherent complexities of the physiological conditions. Despite the inherent complexities of phenomena in the aorta, the predictive model demonstrates consistent error magnitudes for velocity components and wall-related indices, while solid variables show slightly higher errors.
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Affiliation(s)
- Xuan Tang
- Department of Physical Education, Yunnan University, Kunming, Yunnan Province, 650000, China; Department of Physical Education, Jeonbuk National University, Jeonju, Jeollabuk, 54896, Korea
| | - ChaoJie Wu
- Department of Physical Education, Jeonbuk National University, Jeonju, Jeollabuk, 54896, Korea.
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3
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Özcan C, Kocatürk Ö, Işlak C, Öztürk C. Integrated particle image velocimetry and fluid-structure interaction analysis for patient-specific abdominal aortic aneurysm studies. Biomed Eng Online 2023; 22:113. [PMID: 38044423 PMCID: PMC10693692 DOI: 10.1186/s12938-023-01179-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 11/23/2023] [Indexed: 12/05/2023] Open
Abstract
BACKGROUND Understanding the hemodynamics of an abdominal aortic aneurysm (AAA) is crucial for risk assessment and treatment planning. This study introduces a low-cost, patient-specific in vitro AAA model to investigate hemodynamics using particle image velocimetry (PIV) and flow-simulating circuit, validated through fluid-structure interaction (FSI) simulations. METHODS In this study, 3D printing was employed to manufacture a flexible patient-specific AAA phantom using a lost-core casting technique. A pulsatile flow circuit was constructed using off-the-shelf components. A particle image velocimetry (PIV) setup was built using an affordable laser source and global shutter camera, and finally, the flow field inside the AAA was analyzed using open-source software. Fluid-structure interaction (FSI) simulations were performed to enhance our understanding of the flow field, and the results were validated by PIV analysis. Both steady-state and transient flow conditions were investigated. RESULTS Our experimental setup replicated physiological conditions, analyzing arterial wall deformations and flow characteristics within the aneurysm. Under constant flow, peak wall deformations and flow velocities showed deviations within - 12% to + 27% and - 7% to + 5%, respectively, compared to FSI simulations. Pulsatile flow conditions further demonstrated a strong correlation (Pearson coefficient 0.85) in flow velocities and vectors throughout the cardiac cycle. Transient phenomena, particularly the formation and progression of vortex structures during systole, were consistently depicted between experimental and numerical models. CONCLUSIONS By bridging high-fidelity experimental observations with comprehensive computational analyses, this study underscores the potential of integrated methodologies in enhancing our understanding of AAA pathophysiology. The convergence of realistic AAA phantoms, precise PIV measurements at affordable cost point, and validated FSI models heralds a new paradigm in vascular research, with significant implications for personalized medicine and bioengineering innovations.
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Affiliation(s)
- Can Özcan
- Institute of Biomedical Engineering, Boğaziçi University, Kandilli Campus, Feza Gürsey Bld., Çengelköy, 34685, Istanbul, Turkey.
| | - Özgür Kocatürk
- Institute of Biomedical Engineering, Boğaziçi University, Kandilli Campus, Feza Gürsey Bld., Çengelköy, 34685, Istanbul, Turkey
| | - Civan Işlak
- Department of Radiology, Division of Neuroradiology, Cerrahpaşa Medical Faculty, Istanbul University Cerrahpaşa, Istanbul, Turkey
| | - Cengizhan Öztürk
- Institute of Biomedical Engineering, Boğaziçi University, Kandilli Campus, Feza Gürsey Bld., Çengelköy, 34685, Istanbul, Turkey
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4
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Bäumler K, Phillips EH, Grande Gutiérrez N, Fleischmann D, Marsden AL, Goergen CJ. Longitudinal investigation of aortic dissection in mice with computational fluid dynamics. Comput Methods Biomech Biomed Engin 2023:1-14. [PMID: 37897230 DOI: 10.1080/10255842.2023.2274281] [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: 05/18/2023] [Accepted: 09/30/2023] [Indexed: 10/29/2023]
Abstract
Predicting late adverse events in aortic dissections is challenging. One commonly observed risk factor is partial thrombosis of the false lumen. In this study we investigated false lumen thrombus progression over 7 days in four mice with angiotensin II-induced aortic dissection. We performed computational fluid dynamic simulations with subject-specific boundary conditions from velocity and pressure measurements. We investigated endothelial cell activation potential, mean velocity, thrombus formation potential, and other hemodynamic factors. Our findings support the hypothesis that flow stagnation is the predominant hemodynamic factor driving a large thrombus ratio in false lumina, particularly those with a single fenestration.
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Affiliation(s)
| | - Evan H Phillips
- Weldon School of Biomedical Engineering, Purdue University, IN, USA
- Department of Pharmaceutical Sciences, University of IL at Chicago, IL, USA
| | | | | | - Alison L Marsden
- Department of Bioengineering, Stanford University, CA, USA
- Department of Pediatrics (Cardiology), Stanford University, CA, USA
| | - Craig J Goergen
- Weldon School of Biomedical Engineering, Purdue University, IN, USA
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Bailey DM, Davies RG, Rose GA, Lewis MH, Aldayem AA, Twine CP, Awad W, Jubouri M, Mohammed I, Mestres CA, Chen EP, Coselli JS, Williams IM, Bashir M. Myths and methodologies: Cardiopulmonary exercise testing for surgical risk stratification in patients with an abdominal aortic aneurysm; balancing risk over benefit. Exp Physiol 2023; 108:1118-1131. [PMID: 37232485 PMCID: PMC10988440 DOI: 10.1113/ep090816] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 05/03/2023] [Indexed: 05/27/2023]
Abstract
The extent to which patients with an abdominal aortic aneurysm (AAA) should exercise remains unclear, given theoretical concerns over the perceived risk of blood pressure-induced rupture, which is often catastrophic. This is especially pertinent during cardiopulmonary exercise testing, when patients are required to perform incremental exercise to symptom-limited exhaustion for the determination of cardiorespiratory fitness. This multimodal metric is being used increasingly as a complementary diagnostic tool to inform risk stratification and subsequent management of patients undergoing AAA surgery. In this review, we bring together a multidisciplinary group of physiologists, exercise scientists, anaesthetists, radiologists and surgeons to challenge the enduring 'myth' that AAA patients should be fearful of and avoid rigorous exercise. On the contrary, by appraising fundamental vascular mechanobiological forces associated with exercise, in conjunction with 'methodological' recommendations for risk mitigation specific to this patient population, we highlight that the benefits conferred by cardiopulmonary exercise testing and exercise training across the continuum of intensity far outweigh the short-term risks posed by potential AAA rupture.
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Affiliation(s)
- Damian M. Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
| | - Richard G. Davies
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
- Department of AnaestheticsUniversity Hospital of WalesCardiffUK
| | - George A. Rose
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
| | - Michael H. Lewis
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
| | | | | | - Wael Awad
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
- Department of Cardiothoracic SurgeryBart's Heart Centre, St Bartholomew's Hospital, Bart's Health NHS TrustLondonUK
| | | | - Idhrees Mohammed
- Institute of Cardiac and Aortic DisordersSRM Institutes for Medical Science (SIMS Hospital)ChennaiTamil NaduIndia
| | - Carlos A. Mestres
- Department of Cardiac SurgeryUniversity Hospital ZürichZürichSwitzerland
| | - Edward P. Chen
- Division of Cardiovascular and Thoracic SurgeryDuke University Medical CenterDurhamNorth CarolinaUSA
| | - Joseph S. Coselli
- Division of Cardiothoracic Surgery, Michael E. DeBakey Department of SurgeryBaylor College of MedicineHoustonTexasUSA
- The Texas Heart InstituteHoustonTexasUSA
- St Luke's‐Baylor St. Luke's Medical CenterHoustonTexasUSA
| | - Ian M. Williams
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
- Department of Vascular SurgeryUniversity Hospital of WalesCardiffUK
| | - Mohamad Bashir
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
- Vascular and Endovascular SurgeryHealth & Education Improvement WalesCardiffUK
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Peng C, He W, Huang X, Ma J, Yuan T, Shi Y, Wang S. The study on the impact of AAA wall motion on the hemodynamics based on 4D CT image data. Front Bioeng Biotechnol 2023; 11:1103905. [PMID: 37064230 PMCID: PMC10098133 DOI: 10.3389/fbioe.2023.1103905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/15/2023] [Indexed: 04/03/2023] Open
Abstract
Purpose: To analyze the effect of the physiological deformation of the vessel wall on the hemodynamics in the abdominal aortic aneurysm (AAA), this paper compared the hemodynamics in AAA based on the moving boundary (MB) simulation and the rigid wall (RW) simulation.Method: Patient-specific models were reconstructed to generate mesh based on four-dimensional computed tomography angiography (4D CT) data. The dynamic mesh technique was used to achieve deformation of the vessel wall, surface mesh and volume mesh of the fluid domain were successively remeshed at each time step. Besides, another rigid wall simulation was performed. Hemodynamics obtained from these two simulations were compared.Results: Flow field and wall shear stress (WSS) distribution are similar. When using the moving boundary method (MBM), mean time-averaged wall shear stress (TAWSS) is lower, mean oscillatory shear index (OSI) and mean relative residence time (RRT) are higher. When using the 10th and 20th percentile values for TAWSS and 80th and 90th percentile values for RRT, the ratios of areas with low TAWSS, high OSI and high RRT to the entire vessel wall are higher than those assuming the vessel as rigid. In addition, one overlapping region of low TAWSS, high OSI and high RRT by using the MBM is consistent with the location of thrombus obtained from the follow-up imaging data.Conclusion: The hemodynamics results by using the MBM reflect a higher blood retention effect. This paper presents a potential tool to assess the risk of intraluminal thrombus (ILT) formation based on the MBM.
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Affiliation(s)
- Chen Peng
- Department of Aeronautics and Astronautics, Institute of Biomechanics, Fudan University, Shanghai, China
| | - Wei He
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xingsheng Huang
- Shenzhen Raysight Intelligent Medical Technology Corporation, Shenzhen, Guangdong, China
| | - Jun Ma
- Shenzhen Raysight Intelligent Medical Technology Corporation, Shenzhen, Guangdong, China
| | - Tong Yuan
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yun Shi
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
- Institute of Vascular Surgery, Fudan University, Shanghai, China
- National Clinical Research Center for Interventional Medicine, Fudan University, Shanghai, China
- *Correspondence: Yun Shi, ; Shengzhang Wang,
| | - Shengzhang Wang
- Department of Aeronautics and Astronautics, Institute of Biomechanics, Fudan University, Shanghai, China
- Institute of Biomedical Engineering Technology, Academy for Engineering and Technology, Fudan University, Shanghai, China
- Yiwu Research Institute, Fudan University, Yiwu, Zhejiang, China
- *Correspondence: Yun Shi, ; Shengzhang Wang,
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Hong SG, Shin J, Aldokhayyil M, Brown MD, Park JY. Mitochondrial and Metabolic Adaptations to Exercise-Induced Fluid Shear Stress in Endothelial Cells. Exerc Sport Sci Rev 2022; 50:145-155. [PMID: 35152237 PMCID: PMC9203873 DOI: 10.1249/jes.0000000000000289] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recent studies have greatly advanced our understanding of the central role of mitochondria on endothelial function. Here, we propose a hypothesis that unidirectional laminar (pulsatile) flow and disturbed laminar (oscillatory) flow may differentially modulate mitochondrial phenotypes in the context of their bioenergetic, signaling, and biosynthetic functions, providing novel insights into subcellular mechanisms underlying how exercise benefits the improvement of vascular health.
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Affiliation(s)
- Soon-Gook Hong
- Department of Kinesiology & Cardiovascular Research Center, Temple University, Philadelphia, PA
| | - Junchul Shin
- Department of Kinesiology & Cardiovascular Research Center, Temple University, Philadelphia, PA
| | | | | | - Joon-Young Park
- Department of Kinesiology & Cardiovascular Research Center, Temple University, Philadelphia, PA
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8
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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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9
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Williamson PN, Docherty PD, Yazdi SG, Khanafer A, Kabaliuk N, Jermy M, Geoghegan PH. Review of the Development of Hemodynamic Modeling Techniques to Capture Flow Behavior in Arteries Affected by Aneurysm, Atherosclerosis, and Stenting. J Biomech Eng 2022; 144:1128816. [PMID: 34802061 DOI: 10.1115/1.4053082] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Indexed: 02/05/2023]
Abstract
Cardiovascular diseases (CVDs) are the leading cause of death in the developed world. CVD can include atherosclerosis, aneurysm, dissection, or occlusion of the main arteries. Many CVDs are caused by unhealthy hemodynamics. Some CVDs can be treated with the implantation of stents and stent grafts. Investigations have been carried out to understand the effects of stents and stent grafts have on arteries and the hemodynamic changes post-treatment. Numerous studies on stent hemodynamics have been carried out using computational fluid dynamics (CFD) which has yielded significant insight into the effect of stent mesh design on near-wall blood flow and improving hemodynamics. Particle image velocimetry (PIV) has also been used to capture behavior of fluids that mimic physiological hemodynamics. However, PIV studies have largely been restricted to unstented models or intra-aneurysmal flow rather than peri or distal stent flow behaviors. PIV has been used both as a standalone measurement method and as a comparison to validate the CFD studies. This article reviews the successes and limitations of CFD and PIV-based modeling methods used to investigate the hemodynamic effects of stents. The review includes an overview of physiology and relevant mechanics of arteries as well as consideration of boundary conditions and the working fluids used to simulate blood for each modeling method along with the benefits and limitations introduced.
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Affiliation(s)
- Petra N Williamson
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Paul D Docherty
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Sina G Yazdi
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Adib Khanafer
- Vascular, Endovascular, and Renal Transplant Unit, Christchurch Hospital, Canterbury District Health Board, Riccarton Avenue, Christchurch 8053, New Zealand; Christchurch School of Medicine, University of Otago, Dunedin 9016, New Zealand
| | - Natalia Kabaliuk
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Mark Jermy
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand
| | - Patrick H Geoghegan
- School of Life and Health Sciences, Aston University, Birmingham B4 7ET, UK; Department of Mechanical and Industrial Engineering, University of South Africa, Johannesburg 2006, South Africa
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Meister BM, Hong SG, Shin J, Rath M, Sayoc J, Park JY. Healthy versus Unhealthy Adipose Tissue Expansion: the Role of Exercise. J Obes Metab Syndr 2022; 31:37-50. [PMID: 35283364 PMCID: PMC8987461 DOI: 10.7570/jomes21096] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 12/29/2021] [Accepted: 12/30/2021] [Indexed: 12/14/2022] Open
Abstract
Although the hallmark of obesity is the expansion of adipose tissue, not all adipose tissue expansion is the same. Expansion of healthy adipose tissue is accompanied by adequate capillary angiogenesis and mitochondria-centered metabolic integrity, whereas expansion of unhealthy adipose tissue is associated with capillary and mitochondrial derangement, resulting in deposition of immune cells (M1-stage macrophages) and excess production of pro-inflammatory cytokines. Accumulation of these dysfunctional adipose tissues has been linked to the development of obesity comorbidities, such as type 2 diabetes, hypertension, dyslipidemia, and cardiovascular disease, which are leading causes of human mortality and morbidity in modern society. Mechanistically, vascular rarefaction and mitochondrial incompetency (for example, low mitochondrial content, fragmented mitochondria, defective mitochondrial respiratory function, and excess production of mitochondrial reactive oxygen species) are frequently observed in adipose tissue of obese patients. Recent studies have demonstrated that exercise is a potent behavioral intervention for preventing and reducing obesity and other metabolic diseases. However, our understanding of potential cellular mechanisms of exercise, which promote healthy adipose tissue expansion, is at the beginning stage. In this review, we hypothesize that exercise can induce unique physiological stimuli that can alter angiogenesis and mitochondrial remodeling in adipose tissues and ultimately promote the development and progression of healthy adipogenesis. We summarize recent reports on how regular exercise can impose differential processes that lead to the formation of either healthy or unhealthy adipose tissue and discuss key knowledge gaps that warrant future research.
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Affiliation(s)
- Benjamin M Meister
- Department of Kinesiology, College of Public Health and Cardiovascular Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Soon-Gook Hong
- Department of Kinesiology, College of Public Health and Cardiovascular Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Junchul Shin
- Department of Kinesiology, College of Public Health and Cardiovascular Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Meghan Rath
- Department of Kinesiology, College of Public Health and Cardiovascular Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Jacqueline Sayoc
- Department of Kinesiology, College of Public Health and Cardiovascular Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Joon-Young Park
- Department of Kinesiology, College of Public Health and Cardiovascular Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
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11
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Peng C, Liu J, He W, Qin W, Yuan T, Kan Y, Wang K, Wang S, Shi Y. Numerical simulation in the abdominal aorta and the visceral arteries with or without stenosis based on 2D PCMRI. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2022; 38:e3569. [PMID: 34967124 DOI: 10.1002/cnm.3569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/10/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
It is important to obtain accurate boundary conditions (BCs) in hemodynamic simulations. This article aimed to improve the accuracy of BCs in computational fluid dynamics (CFD) simulation and analyze the differences in hemodynamics between healthy volunteers and patients with visceral arterial stenosis (VAS). The geometric models of seven cases were reconstructed using the magnetic resonance angiogram (MRA) or computed tomography angiogram (CTA) imaging data. The physiological flow waveforms obtained from 2D Phase Contrast Magnetic Resonance Imaging (PCMRI) were imposed on the aortic inlet and the visceral arteries' outlets. The individualized RCR values of the three-element Windkessel model were imposed on the aortic outlet. CFD simulations were run in the open-source software: svSolver. Two specific time points were selected to compare the hemodynamics of healthy volunteers and patients with VAS. The results suggested that blood in the stenotic visceral arteries flowed at high speed throughout the cardiac cycle. The low pressure is distributed at stenotic lesions. The wall shear stress (WSS) reached 4 Pa near stenotic locations. The low time average wall shear stress (TAWSS), high oscillatory shear index (OSI), and high relative residence time (RRT) concentrated in the abdominal aorta. Besides, the ratios of the areas with low TAWSS, high OSI, and high RRT to the computational domain were higher in patients with VAS than which in the healthy volunteers. The individualized BCs were used for hemodynamic simulations and results suggest that patients with stenosis have a higher risk of blood retention and atherosclerosis formation in the abdominal aorta.
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Affiliation(s)
- Chen Peng
- Department of Aeronautics and Astronautics, Institute of Biomechanics, Fudan University, Shanghai, China
| | - Junzhen Liu
- Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Wei He
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Wang Qin
- Department of Aeronautics and Astronautics, Institute of Biomechanics, Fudan University, Shanghai, China
| | - Tong Yuan
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yuanqing Kan
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Keqiang Wang
- Institute of Panvascular Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Shengzhang Wang
- Department of Aeronautics and Astronautics, Institute of Biomechanics, Fudan University, Shanghai, China
- Institute of Biomedical Engineering Technology, Academy for Engineering and Technology, Fudan University, Shanghai, China
| | - Yun Shi
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
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12
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Perissiou M, Bailey TG, Saynor ZL, Shepherd A, Harwood AE, Askew CD. The physiological and clinical importance of cardiorespiratory fitness in people with abdominal aortic aneurysm. Exp Physiol 2022; 107:283-298. [PMID: 35224790 PMCID: PMC9311837 DOI: 10.1113/ep089710] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 02/21/2022] [Indexed: 12/01/2022]
Abstract
New Findings What is the topic of this review? This review focuses on the physiological impact of abdominal aortic aneurysm (AAA) on cardiorespiratory fitness and the negative consequences of low fitness on clinical outcomes in AAA. We also discuss the efficacy of exercise training for improving cardiorespiratory fitness in AAA. What advances does it highlight? We demonstrate the negative impact of low fitness on disease progression and clinical outcomes in AAA. We highlight potential mechanistic determinants of low fitness in AAA and present evidence that exercise training can be an effective treatment strategy for improving cardiorespiratory fitness, postoperative mortality and disease progression.
Abstract An abdominal aortic aneurysm (AAA) is an abnormal enlargement of the aorta, below the level of the renal arteries, where the aorta diameter increases by >50%. As an aneurysm increases in size, there is a progressive increase in the risk of rupture, which ranges from 25 to 40% for aneurysms >5.5 cm in diameter. People with AAA are also at a heightened risk of cardiovascular events and associated mortality. Cardiorespiratory fitness is impaired in people with AAA and is associated with poor (postoperative) clinical outcomes, including increased length of hospital stay and postoperative mortality after open surgical or endovascular AAA repair. Although cardiorespiratory fitness is a well‐recognized prognostic marker of cardiovascular health and mortality, it is not assessed routinely, nor is it included in current clinical practice guidelines for the management of people with AAA. In this review, we discuss the physiological impact of AAA on cardiorespiratory fitness, in addition to the consequences of low cardiorespiratory fitness on clinical outcomes in people with AAA. Finally, we summarize current evidence for the effect of exercise training interventions on cardiorespiratory fitness in people with AAA, including the associated improvements in postoperative mortality, AAA growth and cardiovascular risk. Based on this review, we propose that cardiorespiratory fitness should be considered as part of the routine risk assessment and monitoring of people with AAA and that targeting improvements in cardiorespiratory fitness with exercise training might represent a viable adjunct treatment strategy for reducing postoperative mortality and disease progression.
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Affiliation(s)
- Maria Perissiou
- Physical Activity Health and Rehabilitation Thematic Research Group School of Sport Health and Exercise Science Faculty of Science and Health University of Portsmouth Portsmouth UK
| | - Tom G. Bailey
- Physiology and ultrasound Laboratory in Science and Exercise Centre for Research on Exercise Physical Activity and Health School of Human Movement and Nutrition Sciences University of Queensland Brisbane Australia
- School of Nursing Midwifery and Social Work University of Queensland Brisbane Australia
| | - Zoe L. Saynor
- Physical Activity Health and Rehabilitation Thematic Research Group School of Sport Health and Exercise Science Faculty of Science and Health University of Portsmouth Portsmouth UK
| | - Anthony Shepherd
- Physical Activity Health and Rehabilitation Thematic Research Group School of Sport Health and Exercise Science Faculty of Science and Health University of Portsmouth Portsmouth UK
| | - Amy E. Harwood
- Centre for Sport Exercise & Life Sciences Institute of Health and Wellbeing Coventry University Coventry UK
| | - Christopher D. Askew
- VasoActive Research Group School of Health and Behavioural Sciences University of the Sunshine Coast Sippy Downs Queensland Australia
- Sunshine Cost Health Institute Sunshine Coast Hospital and Health Service Birtinya Queensland Australia
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13
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Bappoo N, Syed MBJ, Khinsoe G, Kelsey LJ, Forsythe RO, Powell JT, Hoskins PR, McBride OMB, Norman PE, Jansen S, Newby DE, Doyle BJ. Low Shear Stress at Baseline Predicts Expansion and Aneurysm-Related Events in Patients With Abdominal Aortic Aneurysm. Circ Cardiovasc Imaging 2021; 14:1112-1121. [PMID: 34875845 DOI: 10.1161/circimaging.121.013160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Low shear stress has been implicated in abdominal aortic aneurysm (AAA) expansion and clinical events. We tested the hypothesis that low shear stress in AAA at baseline is a marker of expansion rate and future aneurysm-related events. METHODS Patients were imaged with computed tomography angiography at baseline and followed up every 6 months >24 months with ultrasound measurements of maximum diameter. From baseline computed tomography angiography, we reconstructed 3-dimensional models for automated computational fluid dynamics simulations and computed luminal shear stress. The primary composite end point was aneurysm repair and/or rupture, and the secondary end point was aneurysm expansion rate. RESULTS We included 295 patients with median AAA diameter of 49 mm (interquartile range, 43-54 mm) and median follow-up of 914 (interquartile range, 670-1112) days. There were 114 (39%) aneurysm-related events, with 13 AAA ruptures and 98 repairs (one rupture was repaired). Patients with low shear stress (<0.4 Pa) experienced a higher number of aneurysm-related events (44%) compared with medium (0.4-0.6 Pa; 27%) and high (>0.6 Pa; 29%) shear stress groups (P=0.010). This association was independent of known risk factors (adjusted hazard ratio, 1.72 [95% CI, 1.08-2.73]; P=0.023). Low shear stress was also independently associated with AAA expansion rate (β=+0.28 mm/y [95% CI, 0.02-0.53]; P=0.037). CONCLUSIONS We show for the first time that low shear stress (<0.4 Pa) at baseline is associated with both AAA expansion and future aneurysm-related events. Aneurysms within the lowest tertile of shear stress, versus those with higher shear stress, were more likely to rupture or reach thresholds for elective repair. Larger prospective validation trials are needed to confirm these findings and translate them into clinical management.
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Affiliation(s)
- Nikhilesh Bappoo
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and the UWA Centre for Medical Research (N.B., G.K., L.J.K., P.E.N., B.J.D.), The University of Western Australia, Perth.,School of Engineering (N.B., G.K., L.J.K., B.K.D.), The University of Western Australia, Perth
| | - Maaz B J Syed
- Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, United Kingdom (M.B.J.S., R.O.F., P.R.H., O.M.B.M., D.E.N., B.J.D.)
| | - Georgia Khinsoe
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and the UWA Centre for Medical Research (N.B., G.K., L.J.K., P.E.N., B.J.D.), The University of Western Australia, Perth.,School of Engineering (N.B., G.K., L.J.K., B.K.D.), The University of Western Australia, Perth
| | - Lachlan J Kelsey
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and the UWA Centre for Medical Research (N.B., G.K., L.J.K., P.E.N., B.J.D.), The University of Western Australia, Perth.,School of Engineering (N.B., G.K., L.J.K., B.K.D.), The University of Western Australia, Perth
| | - Rachael O Forsythe
- Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, United Kingdom (M.B.J.S., R.O.F., P.R.H., O.M.B.M., D.E.N., B.J.D.)
| | - Janet T Powell
- Vascular Surgery Research Group, Imperial College London, London, United Kingdom (J.T.P.)
| | - Peter R Hoskins
- Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, United Kingdom (M.B.J.S., R.O.F., P.R.H., O.M.B.M., D.E.N., B.J.D.).,Biomedical Engineering, Dundee University, United Kingdom (P.R.H.)
| | - Olivia M B McBride
- Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, United Kingdom (M.B.J.S., R.O.F., P.R.H., O.M.B.M., D.E.N., B.J.D.)
| | - Paul E Norman
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and the UWA Centre for Medical Research (N.B., G.K., L.J.K., P.E.N., B.J.D.), The University of Western Australia, Perth.,Medical School (P.E.N., S.J.), The University of Western Australia, Perth
| | - Shirley Jansen
- Medical School (P.E.N., S.J.), The University of Western Australia, Perth.,Heart and Vascular Research Institute, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Perth, Australia (S.J.).,Department of Vascular and Endovascular Surgery, Sir Charles Gairdner Hospital, Perth, Australia (S.J.).,Curtin Medical School, Curtin University, Perth, Australia (S.J.)
| | - David E Newby
- Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, United Kingdom (M.B.J.S., R.O.F., P.R.H., O.M.B.M., D.E.N., B.J.D.)
| | - Barry J Doyle
- Vascular Engineering Laboratory, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and the UWA Centre for Medical Research (N.B., G.K., L.J.K., P.E.N., B.J.D.), The University of Western Australia, Perth.,School of Engineering (N.B., G.K., L.J.K., B.K.D.), The University of Western Australia, Perth.,Centre for Cardiovascular Science, Queens Medical Research Institute, University of Edinburgh, United Kingdom (M.B.J.S., R.O.F., P.R.H., O.M.B.M., D.E.N., B.J.D.).,Australian Research Council Centre for Personalised Therapeutics Technologies (B.J.D.)
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14
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Shi Y, Peng C, Liu J, Lan H, Li C, Qin W, Yuan T, Kan Y, Wang S, Fu W. A modified method of computed fluid dynamics simulation in abdominal aorta and visceral arteries. Comput Methods Biomech Biomed Engin 2021; 24:1718-1729. [PMID: 34569360 DOI: 10.1080/10255842.2021.1912742] [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: 10/20/2022]
Abstract
PURPOSE The flow velocity of visceral arteries was measured by 2D PCMRI to produce the patient-specific flow BC imposed on the outlets of visceral arteries in CFD simulation. This modified method aimed to improve the CFD accuracy in the abdominal aorta and visceral arteries. METHODS A volunteer underwent non-contrast-enhanced MRA to scan the abdominal aorta and visceral arteries, and 2D PCMRI to obtain the flow velocity of the aforementioned vessels. The three-dimensional geometric model was reconstructed using the MRI scan data of the abdominal aorta and visceral arteries. The flow waveforms measured by 2D PCMRI were processed and then imposed on the aortic inlet and the outlets of all visceral arteries as the flow BC. The RCR parameters of the three elements Windkessel model were modulated and imposed on the aortic outlet. CFD simulation was run in the open-source software: svSolver. The same volunteer underwent 4D flow MRI to compare the flow field with those extracted from CFD results. RESULTS Four specific time points in a cardiac cycle and three cross-sectional planes of aorta were selected to analyze the flow field, pressure and wall shear stress (WSS) from CFD. The flow waveforms and streamlines of CFD agreed with those of 4D flow MRI. The pressure waveforms, pressure distribution and WSS distribution from CFD conformed with the physiological condition of human body. CONCLUSION These results suggest this modified CFD method may yield reasonable flow field, pressure and WSS in the abdominal aorta and visceral arteries.
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Affiliation(s)
- Yun Shi
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Chen Peng
- Department of aeronautics and astronautics, Fudan University, Shanghai, China
| | - Junzhen Liu
- Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Hongzhi Lan
- Shenzhen Raysight Intelligent Medical Technology Corporation, Shenzhen, China
| | - Chong Li
- Department of MR Enhance Application, GE Healthcare, Shanghai, China
| | - Wang Qin
- Department of aeronautics and astronautics, Fudan University, Shanghai, China
| | - Tong Yuan
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yuanqing Kan
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Shengzhang Wang
- Department of aeronautics and astronautics, Fudan University, Shanghai, China
| | - Weiguo Fu
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
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15
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Choudhury S, Anupindi K, Patnaik BSV. A study on the transport and interaction between blood flow and low-density-lipoprotein in near-wall regions of blood vessels. Comput Methods Biomech Biomed Engin 2021; 24:1473-1487. [PMID: 33966566 DOI: 10.1080/10255842.2021.1893311] [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: 10/21/2022]
Abstract
Differences in the dynamics and transport of blood make certain regions of the arterial network the preferred sites for initiation and formation of arterial diseases like stenosis and aneurysms. Understanding of such arterial diseases is directly linked to critical hemodynamic parameters such as the wall shear stress (WSS). The present work generalises the influence of WSS on the concentration of LDL that was observed in an earlier study. To this end, a wide variety of simplified flow domain, inspired by the near-wall regions of aneurysms and stenosis, are constructed and analyzed. The effects of pulsatile inflow condition, rheology of blood and curvature of the wall on the correlation between WSS and LDL concentration are investigated. It is demonstrated that the time-scale of variation of lumen-surface-concentration (LSC) of LDL is larger than a single cardiac cycle. As a consequence, the time-average values of WSS are sufficient to locate the regions of higher LSC. This idea is strengthened by making use of simplified flow domain that generates moving stagnation point. Further, it was observed that the rheology of the blood and curvature of the wall does not affect the observed correlation between the WSS and LDL concentration.
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Affiliation(s)
- Satyajit Choudhury
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - Kameswararao Anupindi
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai, India
| | - B S V Patnaik
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
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16
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Plitman Mayo R, Yaakobovich H, Finkelstein A, Shadden SC, Marom G. Impact of BASILICA on the thrombogenicity potential of valve-in-valve implantations. J Biomech 2021; 118:110309. [PMID: 33601181 DOI: 10.1016/j.jbiomech.2021.110309] [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: 01/07/2021] [Accepted: 02/03/2021] [Indexed: 01/17/2023]
Abstract
Subclinical leaflet thrombosis is becoming a major concern in valve-in-valve procedures, whereby a transcatheter aortic valve device is deployed inside a failed bioprosthetic surgical valve. Blood flow stagnation and prolonged residence times in the neo-sinuses have been suggested as possible explanations for leaflet thrombosis. The BASILICA technique, which was originally developed to treat coronary flow obstruction, has also been proposed as an alternative to reduce the risk of thrombus formation. The aim of this study is to understand the impact of BASILICA on the valve-in-valve thrombogenicity using computational fluid dynamics simulations. To this end, two Eulerian and two Lagrangian approaches were employed to estimate near-wall stagnation measures in eight valve-in-valve models. The models included an intact or lacerated Sorin Mitroflow surgical valve, and either a SAPIEN or Evolut transcatheter aortic valve device. The Lagrangian approaches predicted a high number of particles and vortices concentration in the proximal areas of the neo-sinuses, while the Eulerian approaches did so in the distal areas. As a consequence, this study demonstrated that Lagrangian approaches are better predictors of subclinical leaflet thrombosis, since they match experimental and clinical findings. Additionally, the SAPIEN valve possess a higher risk for developing leaflet thrombosis, and two lacerations are shown to provide the best results in terms of development of vortices and accumulation of particles within the neo-sinuses. This study highlights the potential of computational modeling in aiding clinicians in their decision-making in valve-in-valve and BASILICA procedures.
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Affiliation(s)
| | - Halit Yaakobovich
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | | | - Shawn C Shadden
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Gil Marom
- School of Mechanical Engineering, Tel Aviv University, Tel Aviv, Israel.
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17
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Sangha GS, Goergen CJ, Prior SJ, Ranadive SM, Clyne AM. Preclinical techniques to investigate exercise training in vascular pathophysiology. Am J Physiol Heart Circ Physiol 2021; 320:H1566-H1600. [PMID: 33385323 PMCID: PMC8260379 DOI: 10.1152/ajpheart.00719.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Atherosclerosis is a dynamic process starting with endothelial dysfunction and inflammation and eventually leading to life-threatening arterial plaques. Exercise generally improves endothelial function in a dose-dependent manner by altering hemodynamics, specifically by increased arterial pressure, pulsatility, and shear stress. However, athletes who regularly participate in high-intensity training can develop arterial plaques, suggesting alternative mechanisms through which excessive exercise promotes vascular disease. Understanding the mechanisms that drive atherosclerosis in sedentary versus exercise states may lead to novel rehabilitative methods aimed at improving exercise compliance and physical activity. Preclinical tools, including in vitro cell assays, in vivo animal models, and in silico computational methods, broaden our capabilities to study the mechanisms through which exercise impacts atherogenesis, from molecular maladaptation to vascular remodeling. Here, we describe how preclinical research tools have and can be used to study exercise effects on atherosclerosis. We then propose how advanced bioengineering techniques can be used to address gaps in our current understanding of vascular pathophysiology, including integrating in vitro, in vivo, and in silico studies across multiple tissue systems and size scales. Improving our understanding of the antiatherogenic exercise effects will enable engaging, targeted, and individualized exercise recommendations to promote cardiovascular health rather than treating cardiovascular disease that results from a sedentary lifestyle.
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Affiliation(s)
- Gurneet S Sangha
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland
| | - Craig J Goergen
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana.,Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana
| | - Steven J Prior
- Department of Kinesiology, University of Maryland School of Public Health, College Park, Maryland.,Baltimore Veterans Affairs Geriatric Research, Education, and Clinical Center, Baltimore, Maryland
| | - Sushant M Ranadive
- Department of Kinesiology, University of Maryland School of Public Health, College Park, Maryland
| | - Alisa M Clyne
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland
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18
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Takehara Y, Isoda H, Takahashi M, Unno N, Shiiya N, Ushio T, Goshima S, Naganawa S, Alley M, Wakayama T, Nozaki A. Abnormal Flow Dynamics Result in Low Wall Shear Stress and High Oscillatory Shear Index in Abdominal Aortic Dilatation: Initial in vivo Assessment with 4D-flow MRI. Magn Reson Med Sci 2020; 19:235-246. [PMID: 32655086 PMCID: PMC7553816 DOI: 10.2463/mrms.mp.2019-0188] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 05/13/2020] [Indexed: 12/05/2022] Open
Abstract
PURPOSE To characterize the non-laminar flow dynamics and resultant decreased wall shear stress (WSS) and high oscillatory shear index (OSI) of the infrarenal abdominal aortic dilatation, cardiac phase-resolved 3D phase-contrast MRI (4D-flow MRI) was performed. METHODS The prospective single-arm study was approved by the Institutional Review Board and included 18 subjects (median 67.5 years) with the dilated infrarenal aorta (median diameter 35 mm). 4D-flow MRI was conducted on a 1.5T MRI system. On 3D streamline images, laminar and non-laminar (i.e., vortex or helical) flow patterns were visually assessed both for the dilated aorta and for the undilated upstream aorta. Cardiac phase-resolved flow velocities, WSS and OSI, were also measured for the dilated aorta and the upstream undilated aorta. RESULTS Non-laminar flow represented by vortex or helical flow was more frequent and overt in the dilated aorta than in the undilated upstream aorta (P < 0.0156) with a very good interobserver agreement (weighted kappa: 0.82-1.0). The WSS was lower, and the OSI was higher on the dilated aortic wall compared with the proximal undilated segments. In mid-systole, mean spatially-averaged WSS was 0.20 ± 0.016 Pa for the dilated aorta vs. 0.68 ± 0.071 Pa for undilated upstream aorta (P < 0.0001), and OSI on the dilated aortic wall was 0.093 ± 0.010 vs. 0.041 ± 0.0089 (P = 0.013). The maximum values and the amplitudes of the WSS at the dilated aorta were inversely proportional to the ratio of dilated/undilated aortic diameter (r = -0.694, P = 0.0014). CONCLUSION 4D-flow can characterize abnormal non-laminar flow dynamics within the dilated aorta in vivo. The wall of the infrarenal aortic dilatation is continuously and increasingly affected by atherogenic stimuli due to the flow disturbances represented by vortex or helical flow, which is reflected by lower WSS and higher OSI.
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Affiliation(s)
- Yasuo Takehara
- Department of Fundamental Development for Advanced Low Invasive Diagnostic Imaging, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Haruo Isoda
- Department of Brain & Mind Sciences, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Mamoru Takahashi
- Department of Radiology, Seirei Mikatahara General Hospital, Shizuoka, Japan
| | - Naoki Unno
- Department of Vascular Surgery, Hamamatsu Medical Center, Shizuoka, Japan
| | - Norihiko Shiiya
- First Department of Surgery, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Takasuke Ushio
- Department of Diagnostic Radiology & Nuclear Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Satoshi Goshima
- Department of Diagnostic Radiology & Nuclear Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Shinji Naganawa
- Department of Radiology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Marcus Alley
- Department of Radiology, Stanford University School of Medicine, CA, USA
| | | | - Atsushi Nozaki
- MR Applications and Workflow, GE Healthcare Japan, Tokyo, Japan
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19
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Schumacher O, Galvão DA, Taaffe DR, Chee R, Spry N, Newton RU. Exercise modulation of tumour perfusion and hypoxia to improve radiotherapy response in prostate cancer. Prostate Cancer Prostatic Dis 2020; 24:1-14. [PMID: 32632128 PMCID: PMC8012204 DOI: 10.1038/s41391-020-0245-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/25/2020] [Accepted: 06/24/2020] [Indexed: 12/12/2022]
Abstract
Background An increasing number of studies indicate that exercise plays an important role in the overall care of prostate cancer (PCa) patients before, during and after treatment. Historically, research has focused on exercise as a modulator of physical function, psychosocial well-being as well as a countermeasure to cancer- and treatment-related adverse effects. However, recent studies reveal that exercise may also directly influence tumour physiology that could beneficially affect the response to radiotherapy. Methods In this narrative review, we provide an overview of tumour vascular characteristics that limit the effect of radiation and establish a rationale for exercise as adjunct therapy during PCa radiotherapy. Further, we summarise the existing literature on exercise as a modulator of tumour perfusion and hypoxia and outline potential future research directions. Results Preclinical research has shown that exercise can reduce intratumoral hypoxia—a major limiting factor in radiotherapy—by improving tumour perfusion and vascularisation. In addition, preliminary evidence suggests that exercise training can improve radiotherapy treatment outcomes by increasing natural killer cell infiltration in a murine PCa model. Conclusions Exercise is a potentially promising adjunct therapy for men with PCa undergoing radiotherapy that may increase its effectiveness. However, exercise-induced tumour radiosensitisation remains to be confirmed in preclinical and clinical trials, as does the optimal exercise prescription to elicit such effects.
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Affiliation(s)
- Oliver Schumacher
- Exercise Medicine Research Institute, Edith Cowan University, Joondalup, WA, Australia. .,School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.
| | - Daniel A Galvão
- Exercise Medicine Research Institute, Edith Cowan University, Joondalup, WA, Australia.,School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Dennis R Taaffe
- Exercise Medicine Research Institute, Edith Cowan University, Joondalup, WA, Australia.,School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.,School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, QLD, Australia
| | - Raphael Chee
- Exercise Medicine Research Institute, Edith Cowan University, Joondalup, WA, Australia.,School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.,GenesisCare, Joondalup, WA, Australia
| | - Nigel Spry
- Exercise Medicine Research Institute, Edith Cowan University, Joondalup, WA, Australia.,School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.,GenesisCare, Joondalup, WA, Australia
| | - Robert U Newton
- Exercise Medicine Research Institute, Edith Cowan University, Joondalup, WA, Australia.,School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.,School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, QLD, Australia
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20
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Computational Fluid Dynamics Modeling of Hemodynamic Parameters in the Human Diseased Aorta: A Systematic Review. Ann Vasc Surg 2020; 63:336-381. [DOI: 10.1016/j.avsg.2019.04.032] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 03/09/2019] [Accepted: 04/18/2019] [Indexed: 02/07/2023]
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21
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Sakthivel M, Anupindi K. Axisymmetric compact finite-difference lattice Boltzmann method for blood flow simulations. Phys Rev E 2019; 100:043307. [PMID: 31770883 DOI: 10.1103/physreve.100.043307] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Indexed: 06/10/2023]
Abstract
An axisymmetric compact finite-difference lattice Boltzmann method is proposed to simulate both Newtonian and non-Newtonian flow of blood through a lumen. The curvature of the arteries could be accurately resolved using body-fitted mesh owing to the proposed finite-difference formulation. The axisymmetric nature of the flow, as well as the non-Newtonian nature of blood, are incorporated into the lattice Boltzmann equation using separate source terms. Using Chapman-Enskog expansion it is shown that the resulting lattice Boltzmann equation with these additional source terms recovers the macroscopic axisymmetric hydrodynamic equations. The solver is verified for (1) steady inflow of a Newtonian fluid through a stenosed lumen, (2) temporally developing pulsatile flow (Womersley flow) through a straight lumen with Newtonian fluid, and (3) steady inflow of a non-Newtonian fluid through a straight lumen. The solver is then applied to simulate the steady flow of a non-Newtonian fluid through a stenosed lumen, and it was found that a smaller recirculation zone and lower WSS values are obtained when compared with the flow of a Newtonian fluid. The capability of the solver to simulate spatially developing (velocity-driven) pulsatile flow is then demonstrated by simulating physiological pulsatile flow through an axisymmetric abdominal aortic aneurysm. From this simulation, the cycle-averaged wall shear stress is observed to have a steep gradient going from a minimum (negative) to a maximum (positive) value towards the distal end of the aneurysm, which is prone to the risk of rupture. An iterative procedure to select the geometric and flow parameters for unsteady inflow condition in the lattice Boltzmann method framework is demonstrated that accurately resolves all the timescales to achieve incompressibility. Overall, the present solver seems to be promising to simulate axisymmetric flow of blood with steady and pulsatile inflows while considering the blood rheology.
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Affiliation(s)
- M Sakthivel
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamilnadu, India
| | - Kameswararao Anupindi
- Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamilnadu, India
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22
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Morrell MB, Alvarez Florez C, Zhang A, Kleinerman ES, Savage H, Marmonti E, Park M, Shaw A, Schadler KL. Vascular modulation through exercise improves chemotherapy efficacy in Ewing sarcoma. Pediatr Blood Cancer 2019; 66:e27835. [PMID: 31136074 PMCID: PMC6646082 DOI: 10.1002/pbc.27835] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 05/06/2019] [Accepted: 05/10/2019] [Indexed: 12/15/2022]
Abstract
Recent studies in mouse models of cancer have shown that exercise improves tumor vascular function, thereby improving chemotherapy delivery and efficacy. However, the mechanisms underlying this improvement remain unclear and the effect of exercise on Ewing sarcoma (ES), a pediatric bone and soft tissue cancer, is unknown. The effect of exercise on tumor vascular hyperpermeability, which inversely correlates with drug delivery to the tumor, has also not been evaluated. We hypothesized that exercise improves chemotherapy efficacy by enhancing its delivery through improving tumor vascular permeability. We treated ES-bearing mice with doxorubicin with or without moderate treadmill exercise. Exercise did not significantly alter ES tumor vessel morphology. However, compared to control mice, tumors of exercised mice had significantly reduced hyperpermeability, significantly decreased hypoxia, and higher doxorubicin penetration. Compared to doxorubicin alone, doxorubicin plus exercise inhibited tumor growth more efficiently. We evaluated endothelial cell sphingosine-1-phosphate receptors 1 and 2 (S1PR1 and S1PR2) as potential mediators of the improved vascular permeability and increased function afforded by exercise. Relative to tumors from control mice, vessels in tumors from exercised mice had increased S1PR1 and decreased S1PR2 expression. Our results support a model in which exercise remodels ES vasculature to reduce vessel hyperpermeability, potentially via modulation of S1PR1 and S1PR2, thereby improving doxorubicin delivery and inhibiting tumor growth more than doxorubicin alone does. Our data suggest moderate aerobic exercise should be tested in clinical trials as a potentially useful adjuvant to standard chemotherapy for patients with ES.
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Affiliation(s)
- Miriam B.G. Morrell
- Department of Pediatric Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Claudia Alvarez Florez
- Department of Pediatric Research, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Aiqian Zhang
- Department of Pediatric Research, The University of Texas MD Anderson Cancer Center, Houston, Texas,Department of Gynecology, Third Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Eugenie S. Kleinerman
- Department of Pediatric Research, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Hannah Savage
- Department of Pediatric Research, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Enrica Marmonti
- Department of Pediatric Research, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Minjeong Park
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Angela Shaw
- Department of Pediatric Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Keri L. Schadler
- Department of Pediatric Research, The University of Texas MD Anderson Cancer Center, Houston, Texas
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23
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Reza MMS, Arzani A. A critical comparison of different residence time measures in aneurysms. J Biomech 2019; 88:122-129. [DOI: 10.1016/j.jbiomech.2019.03.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 03/16/2019] [Accepted: 03/20/2019] [Indexed: 12/13/2022]
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24
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Leemans EL, Cornelissen BMW, Rosalini G, Verbaan D, Schneiders JJ, van den Berg R, Vandertop WP, van Bavel ET, Slump CH, Majoie CBLM, Marquering HA. Impact of Intracranial Aneurysm Morphology and Rupture Status on the Particle Residence Time. J Neuroimaging 2019; 29:487-492. [PMID: 31002750 PMCID: PMC6618041 DOI: 10.1111/jon.12618] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/29/2019] [Accepted: 04/02/2019] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Aneurysm hemodynamics play an important role in aneurysm growth and subsequent rupture. Within the available hemodynamic characteristics, particle residence time (PRT) is relatively unexplored. However, some studies have shown that PRT is related to thrombus formation and inflammation. The goal of this study is to evaluate the association between PRT and aneurysm rupture and morphology. METHODS We determined the PRT for 113 aneurysms (61 unruptured, 53 ruptured) based on computational fluid dynamic models. Virtual particles were injected into the parent vessel and followed during multiple cardiac cycles. PRT was defined as the time needed for 99% of the particles that entered an aneurysm to leave the aneurysm. Subsequently, we evaluated the association between PRT, rupture, and morphology (aneurysm type, presence of blebs, or multiple lobulations). RESULTS PRT showed no significant difference between unruptured (1.1 seconds interquartile range [IQR .39-2.0 seconds]) and ruptured aneurysms (1.2 seconds [IQR .47-2.3 seconds]). PRT was influenced by aneurysm morphology. Longer PRTs were seen in bifurcation aneurysms (1.3 seconds [IQR .54-2.4 seconds], P = .01) and aneurysms with blebs or multiple lobulations (1.92 seconds [IQR .94-2.8 seconds], P < .001). Four of five partially thrombosed aneurysms had a long residence time (>1.9 seconds). CONCLUSIONS Our study shows an influence of aneurysm morphology on PRT. Nevertheless, it suggests that PRT cannot be used to differentiate unruptured and ruptured aneurysms.
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Affiliation(s)
- E L Leemans
- Department of Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.,Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - B M W Cornelissen
- Department of Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.,Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.,MIRA Institute for Biomedical Engineering and Technical Medicine, University of Twente, Enschede, the Netherlands
| | - G Rosalini
- Department of Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.,Department of Industrial Engineering and Information, University of Pavia, Pavia, Italy
| | - D Verbaan
- Neurosurgical Center Amsterdam, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - J J Schneiders
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - R van den Berg
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - W P Vandertop
- Neurosurgical Center Amsterdam, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - E T van Bavel
- Department of Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - C H Slump
- MIRA Institute for Biomedical Engineering and Technical Medicine, University of Twente, Enschede, the Netherlands
| | - C B L M Majoie
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - H A Marquering
- Department of Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.,Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
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25
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Visualizing and quantifying flow stasis in abdominal aortic aneurysms in men using 4D flow MRI. Magn Reson Imaging 2019; 57:103-110. [DOI: 10.1016/j.mri.2018.11.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/10/2018] [Accepted: 11/11/2018] [Indexed: 01/24/2023]
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26
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Khamdaeng T, Terdtoon P. Regional pulse wave velocity and stress in aneurysmal arch-shaped aorta. Biomed Mater Eng 2018; 29:527-549. [PMID: 30282348 DOI: 10.3233/bme-181007] [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: 11/15/2022]
Abstract
The pulse wave velocity (PWV) has been shown to be associated with the properties of blood vessel and a cardiovascular risk factor such as aneurysm. The global PWV estimation is applied in conventional clinical diagnosis. However, the geometry of blood vessel changes along the wave traveling path and the global PWV estimation may not always detect regional wall changes resulting from cardiovascular diseases. In this study, a fluid structure interaction (FSI) analysis was applied on arch-shaped aortas with and without aneurysm aimed at determining the effects of the number of aneurysm, aneurysm size and the modulus ratio (aneurysm to wall modulus) on the pulse wave propagation and velocity. The characterization for each stage of aneurysmal aorta was simulated by progressively increasing aortic stiffness and aneurysm size. The pulse wave propagations and velocities were estimated from the two-dimensional spatial-temporal plot of the normalized wall displacement based on elastic deformation. The descending forward and arch reflected PWVs of aneurysmal aortic arch models were found up to 9.7% and 122.8%, respectively, deviate from the PWV of non-aneurysmal aortic arch model. The PWV patterns and magnitudes can be used to distinguish the characterization of the normal and aneurysmal aortic walls and shown to be relevant regional markers utilized in clinical diagnosis.
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Affiliation(s)
- Tipapon Khamdaeng
- Department of Agricultural Engineering, Faculty of Engineering and Agro-Industry, Maejo University, Chiang Mai, Thailand
| | - Pradit Terdtoon
- Department of Mechanical Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai, Thailand
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27
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Wang BL, Jin H, Han XQ, Xia Y, Liu NF. Involvement of brain-derived neurotrophic factor in exercise‑induced cardioprotection of post-myocardial infarction rats. Int J Mol Med 2018; 42:2867-2880. [PMID: 30226568 DOI: 10.3892/ijmm.2018.3841] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 08/23/2018] [Indexed: 11/06/2022] Open
Abstract
Exercise induces a number of benefits, including angiogenesis in post‑myocardial infarction (MI); however, the underlying mechanisms have not been fully clarified. Neurotrophic brain‑derived neurotrophic factor (BDNF) serves a protective role in certain adult cardiac diseases through its specific receptor, BDNF/NT‑3 growth factors receptor (TrkB). The present study explored the mechanisms by which exercise improves cardiac function, with a focus on the involvement of the BDNF/TrkB axis. MI rats were assigned to Sham, sedentary, exercise, exercise with K252a (a TrkB inhibitor), and exercise with NG‑nitro‑L‑arginine methyl ester (L‑NAME) groups. The exercise group was subjected to 8 weeks of treadmill running. The results demonstrated that the rats in the exercise group exhibited increased myocardial angiogenesis and improved cardiac function, which was attenuated by K252a. Exercise induced activation of the BDNF/TrkB axis in the ischaemic myocardium and increased serum BDNF levels were abated by exposure to L‑NAME. Improvements in angiogenesis and left ventricular function exhibited a positive association, with changes in serum BDNF. In the in vitro experiments, human umbilical vein endothelial cells were exposed to shear stress (SS) of 12 dyn/cm2 to mimic the effects of exercise training on vascular tissue. An increased tube‑forming capacity, and a nitric oxide (NO)‑dependent prolonged activation of the BDNF/TrkB‑full‑length axis over 12 h, but not the TrkB‑truncated axis, was observed. The SS‑related angiogenic response was attenuated by TrkB inhibition. Overall, these results demonstrate that exercise confers certain aspects of its cardioprotective effects through the activation of the BDNF/TrkB axis in an NO‑dependent manner, a process in which fluid‑induced SS may serve a crucial role.
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Affiliation(s)
- Bi-Lei Wang
- Department of Rehabilitation, Zhongda Hospital, Medical School of Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Hong Jin
- Department and Institute of Cardiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Xi-Qiong Han
- Department and Institute of Cardiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Yang Xia
- Department of Rehabilitation, Zhongda Hospital, Medical School of Southeast University, Nanjing, Jiangsu 210009, P.R. China
| | - Nai-Feng Liu
- Department and Institute of Cardiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, Jiangsu 210009, P.R. China
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28
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Matthews EO, Rowbotham SE, Moxon JV, Jones RE, Vega de Ceniga M, Golledge J. Meta-analysis of the association between peripheral artery disease and growth of abdominal aortic aneurysms. Br J Surg 2017; 104:1765-1774. [DOI: 10.1002/bjs.10675] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/14/2017] [Accepted: 07/11/2017] [Indexed: 12/23/2022]
Abstract
Abstract
Background
The role of atherosclerosis in the pathogenesis of abdominal aortic aneurysm (AAA) is controversial. Atherosclerosis-associated peripheral artery disease (PAD) has been reported to be a risk factor for AAA in population screening studies; its relationship with AAA growth is controversial.
Methods
A systematic search of MEDLINE, Scopus, CINAHL and the Cochrane Central Register of Controlled Trials was conducted in April 2016 and repeated in January 2017. Databases were screened for studies reporting AAA growth rates in patients with, and without PAD. The included studies underwent quality assessment and, where possible, were included in the meta-analysis. A subgroup analysis was performed, including only studies that adjusted for confounding factors.
Results
Seventeen studies, including a total of 4873 patients, met the review entry criteria. Data from 15 studies were included in the meta-analysis. There was marked heterogeneity in study design, methodology and statistical analyses used. In the main analysis, PAD was associated with reduced AAA growth (mean difference – 0·13, 95 per cent c.i. –0·27 to –0·00; P = 0·04). However, statistical significance was not maintained in sensitivity analysis. In a subanalysis that included only data adjusted for other risk factors, no significant association between PAD and AAA growth was found (mean difference –0·11, –0·23 to 0·00; P = 0·05).
Conclusion
This systematic review suggests that currently reported studies demonstrate no robust and consistent association between PAD and reduced AAA growth.
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Affiliation(s)
- E O Matthews
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, Townsville, Queensland, Australia
| | - S E Rowbotham
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, Townsville, Queensland, Australia
- School of Medicine, University of Queensland, Herston, Queensland, Australia
- Department of Vascular Surgery, Royal Brisbane and Women's Hospital, Herston, Queensland, Australia
| | - J V Moxon
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, Townsville, Queensland, Australia
| | - R E Jones
- Division of Tropical Health and Medicine, James Cook University, Townsville, Queensland, Australia
| | - M Vega de Ceniga
- Department of Angiology and Vascular Surgery, Hospital de Galdakao-Usansolo, Bizkaia, Spain
| | - J Golledge
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, Townsville, Queensland, Australia
- Department of Vascular and Endovascular Surgery, Townsville Hospital, Townsville, Queensland, Australia
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29
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Bailey TG, Perissiou M, Windsor MT, Schulze K, Nam M, Magee R, Leicht AS, Green DJ, Greaves K, Golledge J, Askew CD. Effects of acute exercise on endothelial function in patients with abdominal aortic aneurysm. Am J Physiol Heart Circ Physiol 2017; 314:H19-H30. [PMID: 28939648 DOI: 10.1152/ajpheart.00344.2017] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Endothelial dysfunction is observed in patients with abdominal aortic aneurysm (AAA), who have increased risk of cardiovascular events and mortality. This study aimed to assess the acute effects of moderate- and higher-intensity exercise on endothelial function, as assessed by flow-mediated dilation (FMD), in AAA patients (74 ± 6 yr old, n = 22) and healthy adults (72 ± 5 yr old, n = 22). Participants undertook three randomized visits, including moderate-intensity continuous exercise [40% peak power output (PPO)], higher-intensity interval exercise (70% PPO), and a no-exercise control. Brachial artery FMD was assessed at baseline and at 10 and 60 min after each condition. Baseline FMD was lower [by 1.10% (95% confidence interval: 0.72-.81), P = 0.044] in AAA patients than in healthy adults. There were no group differences in FMD responses after each condition ( P = 0.397). FMD did not change after no-exercise control but increased by 1.21% (95% confidence interval: 0.69-1.73, P < 0.001) 10 min after moderate-intensity continuous exercise in both groups and returned to baseline after 60 min. Conversely, FMD decreased by 0.93% (95% confidence interval: 0.41-1.44, P < 0.001) 10 min after higher-intensity interval exercise in both groups and remained decreased after 60 min. We found that the acute response of endothelial function to exercise is intensity-dependent and similar between AAA patients and healthy adults. Our findings provide evidence that regular exercise may improve vascular function in AAA patients, as it does in healthy adults. Improved FMD after moderate-intensity exercise may provide short-term benefit. Whether the decrease in FMD after higher-intensity exercise represents an additional risk and/or a greater stimulus for vascular adaptation remains to be elucidated. NEW & NOTEWORTHY Abdominal aortic aneurysm patients have vascular dysfunction. We observed a short-term increase in vascular function after moderate-intensity exercise. Conversely, higher-intensity exercise induced a prolonged reduction in vascular function, which may be associated with both short-term increases in cardiovascular risk and signaling for longer-term vascular adaptation in abdominal aortic aneurysm patients.
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Affiliation(s)
- Tom G Bailey
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Maria Perissiou
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Mark T Windsor
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Karl Schulze
- Sunshine Vascular Clinic, Buderim, Queensland, Australia
| | - Michael Nam
- Sunshine Coast University Hospital, Sunshine Coast Hospital and Health Service, Birtinya, Queensland, Australia
| | - Rebecca Magee
- Sunshine Coast University Hospital, Sunshine Coast Hospital and Health Service, Birtinya, Queensland, Australia
| | - Anthony S Leicht
- Sport and Exercise Science, James Cook University, Townville, Queensland, Australia
| | - Daniel J Green
- School of Sport Science, Exercise, and Health, University of Western Australia, Crawley, Western Australia, Australia.,Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Liverpool , United Kingdom
| | - Kim Greaves
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, Australia.,Sunshine Coast University Hospital, Sunshine Coast Hospital and Health Service, Birtinya, Queensland, Australia
| | - Jonathan Golledge
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University , Townsville, Queensland , Australia.,Department of Vascular and Endovascular Surgery, Townsville Hospital, Townsville, Queensland, Australia
| | - Christopher D Askew
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, Australia
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30
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Aorta Ascending Aneurysm Analysis Using CFD Models towards Possible Anomalies. FLUIDS 2017. [DOI: 10.3390/fluids2020031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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31
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Improvement of hemodynamic performance using novel helical flow vena cava filter design. Sci Rep 2017; 7:40724. [PMID: 28112186 PMCID: PMC5256025 DOI: 10.1038/srep40724] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 12/09/2016] [Indexed: 12/25/2022] Open
Abstract
We propose a vena cava filter in which helical flow is created in the filter’s working zone to minimize filter blockage by trapped clots and facilitate the lysis of trapped clots. To validate this new design, we compared five helical flow inducers with different thread pitches in terms of blood flow patterns in the filter. The vena cava was reconstructed based on computed tomography images. Both the numerical simulation and in vitro experiment revealed that the helical flow inducer can effectively create a helical flow in the vessel, thereby subduing the filter structure’s adverse disruption to blood flow, and increasing flow-induced shear stress in the filter center. In addition, the smaller thread pitch helical flow inducer reduced the oscillating shear index and relative residence time on the vessel wall. Moreover, we observed that the helical flow inducer in the vena cava could induce flow rotation both in clockwise and counterclockwise directions. In conclusion, the new design of the filter with the smaller thread pitch inducer is advantageous over the traditional filter in terms of improving local hemodynamics, which may reduce thrombosis build-up after deployment.
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32
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Updegrove A, Wilson NM, Merkow J, Lan H, Marsden AL, Shadden SC. SimVascular: An Open Source Pipeline for Cardiovascular Simulation. Ann Biomed Eng 2016; 45:525-541. [PMID: 27933407 DOI: 10.1007/s10439-016-1762-8] [Citation(s) in RCA: 258] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/10/2016] [Indexed: 12/19/2022]
Abstract
Patient-specific cardiovascular simulation has become a paradigm in cardiovascular research and is emerging as a powerful tool in basic, translational and clinical research. In this paper we discuss the recent development of a fully open-source SimVascular software package, which provides a complete pipeline from medical image data segmentation to patient-specific blood flow simulation and analysis. This package serves as a research tool for cardiovascular modeling and simulation, and has contributed to numerous advances in personalized medicine, surgical planning and medical device design. The SimVascular software has recently been refactored and expanded to enhance functionality, usability, efficiency and accuracy of image-based patient-specific modeling tools. Moreover, SimVascular previously required several licensed components that hindered new user adoption and code management and our recent developments have replaced these commercial components to create a fully open source pipeline. These developments foster advances in cardiovascular modeling research, increased collaboration, standardization of methods, and a growing developer community.
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Affiliation(s)
- Adam Updegrove
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Nathan M Wilson
- Open Source Medical Software Corporation, Santa Monica, CA, USA
| | - Jameson Merkow
- Department of Electrical and Computer Engineering, University of California, San Diego, CA, USA
| | - Hongzhi Lan
- Department of Bioengineering, Stanford University, Palo Alto, CA, USA
| | - Alison L Marsden
- Department of Bioengineering, Stanford University, Palo Alto, CA, USA.,Department of Pediatrics, Stanford University, Palo Alto, CA, USA
| | - Shawn C Shadden
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA. .,University of California, Berkeley, CA, 94720-1740, USA.
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33
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Lozowy RJ, Kuhn DCS, Ducas AA, Boyd AJ. The Relationship Between Pulsatile Flow Impingement and Intraluminal Thrombus Deposition in Abdominal Aortic Aneurysms. Cardiovasc Eng Technol 2016; 8:57-69. [DOI: 10.1007/s13239-016-0287-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 11/07/2016] [Indexed: 11/28/2022]
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34
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Schadler KL, Thomas NJ, Galie PA, Bhang DH, Roby KC, Addai P, Till JE, Sturgeon K, Zaslavsky A, Chen CS, Ryeom S. Tumor vessel normalization after aerobic exercise enhances chemotherapeutic efficacy. Oncotarget 2016; 7:65429-65440. [PMID: 27589843 PMCID: PMC5323166 DOI: 10.18632/oncotarget.11748] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 08/25/2016] [Indexed: 12/22/2022] Open
Abstract
Targeted therapies aimed at tumor vasculature are utilized in combination with chemotherapy to improve drug delivery and efficacy after tumor vascular normalization. Tumor vessels are highly disorganized with disrupted blood flow impeding drug delivery to cancer cells. Although pharmacologic anti-angiogenic therapy can remodel and normalize tumor vessels, there is a limited window of efficacy and these drugs are associated with severe side effects necessitating alternatives for vascular normalization. Recently, moderate aerobic exercise has been shown to induce vascular normalization in mouse models. Here, we provide a mechanistic explanation for the tumor vascular normalization induced by exercise. Shear stress, the mechanical stimuli exerted on endothelial cells by blood flow, modulates vascular integrity. Increasing vascular shear stress through aerobic exercise can alter and remodel blood vessels in normal tissues. Our data in mouse models indicate that activation of calcineurin-NFAT-TSP1 signaling in endothelial cells plays a critical role in exercise-induced shear stress mediated tumor vessel remodeling. We show that moderate aerobic exercise with chemotherapy caused a significantly greater decrease in tumor growth than chemotherapy alone through improved chemotherapy delivery after tumor vascular normalization. Our work suggests that the vascular normalizing effects of aerobic exercise can be an effective chemotherapy adjuvant.
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Affiliation(s)
- Keri L. Schadler
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Abramson Family Cancer Research Institute, Philadelphia, PA 19104, USA
| | - Nicholas J. Thomas
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Abramson Family Cancer Research Institute, Philadelphia, PA 19104, USA
| | - Peter A. Galie
- Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Dong Ha Bhang
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Abramson Family Cancer Research Institute, Philadelphia, PA 19104, USA
| | - Kerry C. Roby
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Abramson Family Cancer Research Institute, Philadelphia, PA 19104, USA
| | - Prince Addai
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Abramson Family Cancer Research Institute, Philadelphia, PA 19104, USA
| | - Jacob E. Till
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Abramson Family Cancer Research Institute, Philadelphia, PA 19104, USA
| | - Kathleen Sturgeon
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Abramson Family Cancer Research Institute, Philadelphia, PA 19104, USA
| | - Alexander Zaslavsky
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Abramson Family Cancer Research Institute, Philadelphia, PA 19104, USA
| | | | - Sandra Ryeom
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Abramson Family Cancer Research Institute, Philadelphia, PA 19104, USA
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35
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Hollis L, Conlisk N, Thomas-Seale LEJ, Roberts N, Pankaj P, Hoskins PR. Computational simulations of MR elastography in idealised abdominal aortic aneurysms. Biomed Phys Eng Express 2016. [DOI: 10.1088/2057-1976/2/4/045016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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36
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Sarrami-Foroushani A, Nasr Esfahany M, Saligheh Rad H, Firouznia K, Shakiba M, Ghanaati H. Effects of Variations of Flow and Heart Rate on Intra-Aneurysmal Hemodynamics in a Ruptured Internal Carotid Artery Aneurysm During Exercise. IRANIAN JOURNAL OF RADIOLOGY 2016; 13:e18217. [PMID: 27110332 PMCID: PMC4837368 DOI: 10.5812/iranjradiol.18217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 06/18/2014] [Accepted: 07/20/2014] [Indexed: 11/16/2022]
Abstract
BACKGROUND Hemodynamics is thought to play an important role in the mechanisms responsible for initiation, growth, and rupture of intracranial aneurysms. Computational fluid dynamic (CFD) analysis is used to assess intra-aneurysmal hemodynamics. OBJECTIVES This study aimed to investigate the effects of variations in heart rate and internal carotid artery (ICA) flow rate on intra-aneurysmal hemodynamics, in an ICA aneurysm, by using computational fluid dynamics. PATIENTS AND METHODS Computed tomography angiography (CTA) was performed in a 55 years old female case, with a saccular ICA aneurysm, to create a patient-specific geometrical anatomic model of the aneurysm. The intra-aneurysmal hemodynamic environments for three states with different flow and heart rates were analyzed using patient-specific image-based CFD modeling. RESULTS Results showed significant changes for the three simulated states. For a proportion of the states examined, results were counterintuitive. Systolic and time-averaged wall shear stress and pressure on the aneurysm wall showed a proportional evolution with the mainstream flow rate. CONCLUSION Results reinforced the pivotal role of vascular geometry, with respect to hemodynamics, together with the importance of performing patient-specific CFD analyses, through which the effect of different blood flow conditions on the aneurysm hemodynamics could be evaluated.
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Affiliation(s)
| | - Mohsen Nasr Esfahany
- Department of Chemical Engineering, Isfahan University of Technology, Isfahan, Iran
- Corresponding author: Mohsen Nasr Esfahany, Department of Chemical Engineering, Isfahan University of Technology, Isfahan, Iran. Tel: +98-3133915631, Fax: +98-3113912677, E-mail:
| | - Hamidreza Saligheh Rad
- Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran
| | - Kavous Firouznia
- Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, Iran
| | - Madjid Shakiba
- Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Ghanaati
- Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, Iran
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37
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Luong L, Duckles H, Schenkel T, Mahmoud M, Tremoleda JL, Wylezinska-Arridge M, Ali M, Bowden NP, Villa-Uriol MC, van der Heiden K, Xing R, Gijsen FJ, Wentzel J, Lawrie A, Feng S, Arnold N, Gsell W, Lungu A, Hose R, Spencer T, Halliday I, Ridger V, Evans PC. Heart rate reduction with ivabradine promotes shear stress-dependent anti-inflammatory mechanisms in arteries. Thromb Haemost 2016; 116:181-90. [PMID: 27075869 DOI: 10.1160/th16-03-0214] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 03/28/2016] [Indexed: 01/24/2023]
Abstract
Blood flow generates wall shear stress (WSS) which alters endothelial cell (EC) function. Low WSS promotes vascular inflammation and atherosclerosis whereas high uniform WSS is protective. Ivabradine decreases heart rate leading to altered haemodynamics. Besides its cardio-protective effects, ivabradine protects arteries from inflammation and atherosclerosis via unknown mechanisms. We hypothesised that ivabradine protects arteries by increasing WSS to reduce vascular inflammation. Hypercholesterolaemic mice were treated with ivabradine for seven weeks in drinking water or remained untreated as a control. En face immunostaining demonstrated that treatment with ivabradine reduced the expression of pro-inflammatory VCAM-1 (p<0.01) and enhanced the expression of anti-inflammatory eNOS (p<0.01) at the inner curvature of the aorta. We concluded that ivabradine alters EC physiology indirectly via modulation of flow because treatment with ivabradine had no effect in ligated carotid arteries in vivo, and did not influence the basal or TNFα-induced expression of inflammatory (VCAM-1, MCP-1) or protective (eNOS, HMOX1, KLF2, KLF4) genes in cultured EC. We therefore considered whether ivabradine can alter WSS which is a regulator of EC inflammatory activation. Computational fluid dynamics demonstrated that ivabradine treatment reduced heart rate by 20 % and enhanced WSS in the aorta. In conclusion, ivabradine treatment altered haemodynamics in the murine aorta by increasing the magnitude of shear stress. This was accompanied by induction of eNOS and suppression of VCAM-1, whereas ivabradine did not alter EC that could not respond to flow. Thus ivabradine protects arteries by altering local mechanical conditions to trigger an anti-inflammatory response.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Paul C Evans
- Prof. Paul Evans, Department of Cardiovascular Science, Faculty of Medicine, Dentistry & Health, University of Sheffield, Medical School, Beech Hill Road, Sheffield S10 2RX, UK, Tel.: +44 114 271 2591, Fax: +44 114 271 1863, E-mail:
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Swaelens C, Poole RJ, Torella F, McWilliams RG, England A, Fisher RK. Type IIIb Endoleak and Relining. J Endovasc Ther 2016; 23:297-301. [DOI: 10.1177/1526602816631106] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Purpose: To examine the changes in distraction force following relining of a conventional abdominal aortic stent-graft with a type IIIb endoleak using the Nellix endovascular sealing device compared to a unilateral stent-graft. Methods: Relining is often used to repair type IIIb endoleaks, but the consequences to graft stability are unknown. A mathematical model was constructed based on pressure and volume flow through the stent-grafts, incorporating recognized distraction force equations. Steady flow was presumed at peak systolic pressures to calculate the maximum distraction force, with gravity ignored. Distraction forces for 28- to 36-mm-diameter stent-graft bodies with 16-mm limbs were calculated and compared to forces following relining with single and double Nellix devices or the Renu unilateral device. Results: Distraction forces for the 28-, 32-, and 36-mm stent-grafts prior to relining were 5.99, 10.21, and 14.99 N, respectively. Similar forces were reported after relining with bilateral Nellix devices (5.86, 10.08, and 14.86 N, respectively). However, use of a unilateral Nellix increased the distraction forces to 9.92, 14.14, and 18.92 N, respectively. These were comparable to the increase observed after relining with a Renu unilateral stent-graft (9.87, 14.09, and 18.86 N, respectively). The proportional increase in distraction force for a unilateral relining ranged from 26% to 66%, with the greatest increase noted in the smaller diameter main bodies. Conclusion: Relining a stent-graft with a type IIIb endoleak using bilateral Nellix devices does not increase the distraction force. However, a unilateral Nellix device or the Renu system could theoretically increase the distraction force by up to 66%, potentially risking migration and type Ia endoleak. In clinical practice, these results suggest that a relining with bilateral Nellix may have benefits over the Renu unilateral stent-graft.
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Affiliation(s)
- Charles Swaelens
- Liverpool Vascular and Endovascular Service, Royal Liverpool University Hospital, Liverpool, UK
| | | | - Francesco Torella
- Liverpool Vascular and Endovascular Service, Royal Liverpool University Hospital, Liverpool, UK
| | - Richard G. McWilliams
- Liverpool Vascular and Endovascular Service, Royal Liverpool University Hospital, Liverpool, UK
| | | | - Robert K. Fisher
- Liverpool Vascular and Endovascular Service, Royal Liverpool University Hospital, Liverpool, UK
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Sun A, Tian X, Zhang N, Xu Z, Deng X, Liu M, Liu X. Does lower limb exercise worsen renal artery hemodynamics in patients with abdominal aortic aneurysm? PLoS One 2015; 10:e0125121. [PMID: 25946196 PMCID: PMC4422666 DOI: 10.1371/journal.pone.0125121] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 03/20/2015] [Indexed: 11/19/2022] Open
Abstract
Renal artery stenosis (RAS) and renal complications emerge in some patients after endovascular aneurysm repair (EVAR) to treat abdominal aorta aneurysm (AAA). The mechanisms for the causes of these problems are not clear. We hypothesized that for EVAR patients, lower limb exercise could negatively influence the physiology of the renal artery and the renal function, by decreasing the blood flow velocity and changing the hemodynamics in the renal arteries. To evaluate this hypothesis, pre- and post-operative models of the abdominal aorta were reconstructed based on CT images. The hemodynamic environment was numerically simulated under rest and lower limb exercise conditions. The results revealed that in the renal arteries, lower limb exercise decreased the wall shear stress (WSS), increased the oscillatory shear index (OSI) and increased the relative residence time (RRT). EVAR further enhanced these effects. Because these parameters are related to artery stenosis and atherosclerosis, this preliminary study concluded that lower limb exercise may increase the potential risk of inducing renal artery stenosis and renal complications for AAA patients. This finding could help elucidate the mechanism of renal artery stenosis and renal complications after EVAR and warn us to reconsider the management and nursing care of AAA patients.
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Affiliation(s)
- Anqiang Sun
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Xiaopeng Tian
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Nan Zhang
- Radiologic Department, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Zaipin Xu
- College of Animal Science, Guizhou University, Guiyang, China
| | - Xiaoyan Deng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Ming Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Xiao Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
- * E-mail:
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Zhang P, Liu X, Sun A, Fan Y, Deng X. Hemodynamic insight into overlapping bare-metal stents strategy in the treatment of aortic aneurysm. J Biomech 2015; 48:2041-6. [PMID: 25911250 DOI: 10.1016/j.jbiomech.2015.03.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 03/18/2015] [Accepted: 03/22/2015] [Indexed: 10/23/2022]
Abstract
Clinical trials have shown overlapping bare-metal stents provoke effective thrombus clot within the aneurysm sac and shrinkage of the aneurysm by directly regulating the hemodynamics. To gain insight into the hemodynamic mechanism of the technique, three cases of simplified thoracic aortic aneurysm models (with no stent, a single stent and two overlapped stents deployed within the aneurysm sac) were studied and compared in terms of time-varying velocity and shear rate, time-averaged wall shear stress (TAWSS), oscillating shear index (OSI) and relative residence time (RRT). The results demonstrated that the overlapping stents' strategy was more effective in reducing the velocity of blood flow within the aneurysm, especially for the area near the aneurysm wall. Stenting induced a dramatic change trend of shear rate during the cardiac cycle, in which a very high shear rate (>10,000 s(-1)) during the systole and a quite low shear rate (<1000 s(-1)) during the diastole were observed, respectively. Moreover, reduced TAWSS and OSI and elevated RRT values were observed on the aneurysm wall after stent placement. The effects of stenting on the shear rate, TAWSS, OSI and RRT in the aneurysm would be significantly enhanced by two overlapped stents. The present findings therefore indicated that, the overlapping bare-metal stents can isolate the aneurysm effectively and may create a favorable hemodynamic environment provoking platelets activation and aggregation within the aneurysm, which may promote thrombus formation/growth there, hence contribute to degradation of the aneurysm.
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Affiliation(s)
- Peng Zhang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Xiao Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China.
| | - Anqiang Sun
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Xiaoyan Deng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China.
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Hansen KB, Arzani A, Shadden SC. Mechanical platelet activation potential in abdominal aortic aneurysms. J Biomech Eng 2015; 137:041005. [PMID: 25588057 DOI: 10.1115/1.4029580] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Indexed: 11/08/2022]
Abstract
Intraluminal thrombus (ILT) in abdominal aortic aneurysms (AAA) has potential implications to aneurysm growth and rupture risk; yet, the mechanisms underlying its development remain poorly understood. Some researchers have proposed that ILT development may be driven by biomechanical platelet activation within the AAA, followed by adhesion in regions of low wall shear stress. Studies have investigated wall shear stress levels within AAA, but platelet activation potential (AP) has not been quantified. In this study, patient-specific computational fluid dynamic (CFD) models were used to analyze stress-induced AP within AAA under rest and exercise flow conditions. The analysis was conducted using Lagrangian particle-based and Eulerian continuum-based approaches, and the results were compared. Results indicated that biomechanical platelet activation is unlikely to play a significant role for the conditions considered. No consistent trend was observed in comparing rest and exercise conditions, but the functional dependence of AP on stress magnitude and exposure time can have a large impact on absolute levels of anticipated platelet AP. The Lagrangian method obtained higher peak AP values, although this difference was limited to a small percentage of particles that falls below reported levels of physiologic background platelet activation.
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42
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Di Achille P, Tellides G, Figueroa CA, Humphrey JD. A haemodynamic predictor of intraluminal thrombus formation in abdominal aortic aneurysms. Proc Math Phys Eng Sci 2014. [DOI: 10.1098/rspa.2014.0163] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Intraluminal thrombus (ILT) is present in over 75% of all abdominal aortic aneurysms (AAAs) and probably contributes to the complex biomechanics and pathobiology of these lesions. A reliable predictor of thrombus formation in enlarging lesions could thereby aid clinicians in treatment planning. The primary goal of this work was to identify a new phenomenological metric having clinical utility that is motivated by the hypothesis that two basic haemodynamic features must coincide spatially and temporally to promote the formation of a thrombus on an intact endothelium—platelets must be activated within a shear flow and then be presented to a susceptible endothelium. Towards this end, we propose a new thrombus formation potential (TFP) that combines information on the flow-induced shear history experienced by blood-borne particles that come in close proximity to the endothelium with information on both the time-averaged wall shear stress (WSS) and the oscillatory shear index (OSI) that locally affect the endothelial mechanobiology. To illustrate the possible utility of this new metric, we show computational results for 10 carotid arteries from five patients where regions of low WSS and high OSI tend not to be presented with activated platelets (i.e. they have a low TFP), consistent with the thrombo-resistance of the healthy carotid despite its complex haemodynamics. Conversely, we show results for three patients that high TFP co-localizes with regions of observed thin thrombus in AAAs, which contrasts with findings of low TFP for the abdominal aorta of three healthy subjects. We submit that these promising results suggest the need for further consideration of the TFP, or a similar combined metric, as a potentially useful clinical predictor of the possible formation of ILT in AAAs.
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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
| | - C. A. Figueroa
- Department of Surgery and Biomedical Engineering, University of Michigan, Ann Arbor, MI, 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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43
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Jones SM, Poole RJ, How TV, Williams RL, McWilliams RG, Brennan JA, Vallabhaneni SR, Fisher RK. Computational fluid dynamic analysis of the effect of morphologic features on distraction forces in fenestrated stent grafts. J Vasc Surg 2014; 60:1648-56.e1. [DOI: 10.1016/j.jvs.2014.08.077] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 08/17/2014] [Indexed: 11/15/2022]
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Kim B, Lee H, Kawata K, Park JY. Exercise-mediated wall shear stress increases mitochondrial biogenesis in vascular endothelium. PLoS One 2014; 9:e111409. [PMID: 25375175 PMCID: PMC4222908 DOI: 10.1371/journal.pone.0111409] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 10/02/2014] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Enhancing structural and functional integrity of mitochondria is an emerging therapeutic option against endothelial dysfunction. In this study, we sought to investigate the effect of fluid shear stress on mitochondrial biogenesis and mitochondrial respiratory function in endothelial cells (ECs) using in vitro and in vivo complementary studies. METHODS AND RESULTS Human aortic- or umbilical vein-derived ECs were exposed to laminar shear stress (20 dyne/cm2) for various durations using a cone-and-plate shear apparatus. We observed significant increases in the expression of key genes related to mitochondrial biogenesis and mitochondrial quality control as well as mtDNA content and mitochondrial mass under the shear stress conditions. Mitochondrial respiratory function was enhanced when cells were intermittently exposed to laminar shear stress for 72 hrs. Also, shear-exposed cells showed diminished glycolysis and decreased mitochondrial membrane potential (ΔΨm). Likewise, in in vivo experiments, mice that were subjected to a voluntary wheel running exercise for 5 weeks showed significantly higher mitochondrial content determined by en face staining in the conduit (greater and lesser curvature of the aortic arch and thoracic aorta) and muscle feed (femoral artery) arteries compared to the sedentary control mice. Interestingly, however, the mitochondrial biogenesis was not observed in the mesenteric artery. This region-specific adaptation is likely due to the differential blood flow redistribution during exercise in the different vessel beds. CONCLUSION Taken together, our findings suggest that exercise enhances mitochondrial biogenesis in vascular endothelium through a shear stress-dependent mechanism. Our findings may suggest a novel mitochondrial pathway by which a chronic exercise may be beneficial for vascular function.
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Affiliation(s)
- Boa Kim
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania, United States of America
- Cardiovascular Research Center, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Hojun Lee
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Keisuke Kawata
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Joon-Young Park
- Department of Kinesiology, Temple University, Philadelphia, Pennsylvania, United States of America
- Cardiovascular Research Center, Temple University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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45
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Arzani A, Suh GY, Dalman RL, Shadden SC. A longitudinal comparison of hemodynamics and intraluminal thrombus deposition in abdominal aortic aneurysms. Am J Physiol Heart Circ Physiol 2014; 307:H1786-95. [PMID: 25326533 DOI: 10.1152/ajpheart.00461.2014] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abdominal aortic aneurysm (AAA) is often accompanied by in traluminal thrombus (ILT), which complicates AAA progression and risk of rupture. Patient-specific computational fluid dynamics modeling of 10 small human AAA was performed to investigate relations between hemodynamics and ILT progression. The patients were imaged using magnetic resonance twice in a 2- to 3-yr interval. Wall content data were obtained by a planar T1-weighted fast spin echo black-blood scan, which enabled quantification of thrombus thickness at midaneurysm location during baseline and followup. Computational simulations with patient-specific geometry and boundary conditions were performed to quantify the hemodynamic parameters of time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and mean exposure time at baseline. Spatially resolved quantifications of the change in ILT thickness were compared with the different hemodynamic parameters. Regions of low OSI had the strongest correlation with ILT growth and demonstrated a statistically significant correlation coefficient. Prominent regions of high OSI (>0.4) and low TAWSS (<1 dyn/cm(2)) did not appear to coincide with locations of thrombus deposition.
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Affiliation(s)
- Amirhossein Arzani
- Mechanical Engineering, University of California, Berkeley, California; and
| | - Ga-Young Suh
- Division of Vascular Surgery, Stanford University, Stanford, California
| | - Ronald L Dalman
- Division of Vascular Surgery, Stanford University, Stanford, California
| | - Shawn C Shadden
- Mechanical Engineering, University of California, Berkeley, California; and
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Modeling of the acute effects of primary hypertension and hypotension on the hemodynamics of intracranial aneurysms. Ann Biomed Eng 2014; 43:207-21. [PMID: 25118666 DOI: 10.1007/s10439-014-1076-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 07/23/2014] [Indexed: 10/24/2022]
Abstract
Hemodynamics is a risk factor in intracranial aneurysms (IA). Hypertension and pharmacologically induced hypotension are common in IA patients. This study investigates how hypertension and hypotension may influence aneurysmal hemodynamics. Images of 23 IAs at typical locations were used to build patient-specific Computational Fluid Dynamics models. The effects of hypotension and hypertension were simulated through boundary conditions by modulating the normotensive flow and pressure waveforms, in turn produced by a 1D systemic vascular model. Aneurysm location and flow pattern types were used to categorize the influence of hypotension and hypertension on relevant flow variables (velocity, pressure and wall shear stress). Results indicate that, compared to other locations, vertebrobasilar aneurysms (VBA) are more sensitive to flow changes. In VBAs, space-averaged velocity at peak systole increased by 30% in hypertension (16-21% in other locations). Flow in VBAs in hypotension decreased by 20% (10-13% in other locations). Momentum-driven hemodynamic types were also more affected by hypotension and hypertension, than shear-driven types. This study shows how patient-specific modeling can be effectively used to identify location-specific flow patterns in a clinically-relevant study, thus reinforcing the role played by modeling technologies in furthering our understanding of cardiovascular disease, and their potential in future healthcare.
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47
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Lagrangian postprocessing of computational hemodynamics. Ann Biomed Eng 2014; 43:41-58. [PMID: 25059889 DOI: 10.1007/s10439-014-1070-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Accepted: 07/11/2014] [Indexed: 10/25/2022]
Abstract
Recent advances in imaging, modeling, and computing have rapidly expanded our capabilities to model hemodynamics in the large vessels (heart, arteries, and veins). This data encodes a wealth of information that is often under-utilized. Modeling (and measuring) blood flow in the large vessels typically amounts to solving for the time-varying velocity field in a region of interest. Flow in the heart and larger arteries is often complex, and velocity field data provides a starting point for investigating the hemodynamics. This data can be used to perform Lagrangian particle tracking, and other Lagrangian-based postprocessing. As described herein, Lagrangian methods are necessary to understand inherently transient hemodynamic conditions from the fluid mechanics perspective, and to properly understand the biomechanical factors that lead to acute and gradual changes of vascular function and health. The goal of the present paper is to review Lagrangian methods that have been used in post-processing velocity data of cardiovascular flows.
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Arzani A, Les AS, Dalman RL, Shadden SC. Effect of exercise on patient specific abdominal aortic aneurysm flow topology and mixing. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2014; 30:280-95. [PMID: 24493404 PMCID: PMC3914012 DOI: 10.1002/cnm.2601] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 07/04/2013] [Accepted: 09/04/2013] [Indexed: 05/18/2023]
Abstract
Computational fluid dynamics modeling was used to investigate changes in blood transport topology between rest and exercise conditions in five patient-specific abdominal aortic aneurysm models. MRI was used to provide the vascular anatomy and necessary boundary conditions for simulating blood velocity and pressure fields inside each model. Finite-time Lyapunov exponent fields and associated Lagrangian coherent structures were computed from blood velocity data and were used to compare features of the transport topology between rest and exercise both mechanistically and qualitatively. A mix-norm and mix-variance measure based on fresh blood distribution throughout the aneurysm over time were implemented to quantitatively compare mixing between rest and exercise. Exercise conditions resulted in higher and more uniform mixing and reduced the overall residence time in all aneurysms. Separated regions of recirculating flow were commonly observed in rest, and these regions were either reduced or removed by attached and unidirectional flow during exercise, or replaced with regional chaotic and transiently turbulent mixing, or persisted and even extended during exercise. The main factor that dictated the change in flow topology from rest to exercise was the behavior of the jet of blood penetrating into the aneurysm during systole.
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Affiliation(s)
| | - Andrea S. Les
- Bioengineering, Stanford University, Stanford, CA, USA
| | - Ronald L. Dalman
- Division of Vascular Surgery, Stanford University, Stanford, CA, USA
| | - Shawn C. Shadden
- Mechanical Engineering, University of California, Berkeley, CA, USA
- Correspondence to: S. C. Shadden, 5121 Etcheverry Hall, Berkeley, CA, 94720-1740.,
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Duvernois V, Marsden AL, Shadden SC. Lagrangian analysis of hemodynamics data from FSI simulation. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2013; 29:445-61. [PMID: 23559551 PMCID: PMC3875314 DOI: 10.1002/cnm.2523] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 09/13/2012] [Accepted: 09/21/2012] [Indexed: 05/29/2023]
Abstract
We present the computation of lagrangian-based flow characterization measures for time-dependent, deformable-wall, finite-element blood flow simulations. Applicability of the algorithm is demonstrated in a fluid-structure interaction simulation of blood flow through a total cavopulmonary connection (Fontan procedure), and results are compared with a rigid-vessel simulation. Specifically, we report on several important lagrangian-based measures including flow distributions, finite-time Lyapunov exponent fields, particle residence time, and exposure time calculations. Overall, strong similarity in lagrangian measures of the flow between deformable and rigid-vessel models was observed.
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50
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Abstract
Hemodynamic parameters play an important role in regulating vascular remodeling in arterio-venous fistula (AVF) maturation. Investigating the changes in hemodynamic parameters during AVF maturation is expected to improve our understanding of fistula failure, but very little data on actual temporal changes in human AVFs is available. The present study aimed to assess the feasibility of using a noncontrast-enhanced MRI protocol combined with CFD modeling to relate hemodynamic changes to vascular remodeling following native AVF placement. MR angiography (MRA) and MR velocimetry (MRV) data was acquired peri-operatively, 1 month, and 3 months later in three patients. Vascular geometries were obtained by segmentation of the MRA images. Pulsatile flow simulations were performed in the patient specific vascular geometries with time-dependent boundary conditions prescribed from MRV measurements. A principal result of the study is the description of WSS changes over time in the same patients. The disturbed flow observed in the venous segments resulted in a variability of the WSS distribution and could be responsible for the non-uniform remodeling of the vessel. The artery did not show regions of disturbed flow upstream from the anastomosis, which would be consistent with the uniform remodeling. MRI use demonstrated the ability to provide a comprehensive evaluation of clinically relevant information for the investigation of upper extremity AVFs. 3D geometry from MRA in combination with MRV provides the opportunity to perform detailed CFD analysis of local hemodynamics in order to determine flow descriptors affecting fistula maturation.
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