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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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Antonuccio MN, Gasparotti E, Bardi F, Monteleone A, This A, Rouet L, Avril S, Celi S. Fabrication of deformable patient-specific AAA models by material casting techniques. Front Cardiovasc Med 2023; 10:1141623. [PMID: 37753165 PMCID: PMC10518418 DOI: 10.3389/fcvm.2023.1141623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 08/24/2023] [Indexed: 09/28/2023] Open
Abstract
Background Abdominal Aortic Aneurysm (AAA) is a balloon-like dilatation that can be life-threatening if not treated. Fabricating patient-specific AAA models can be beneficial for in-vitro investigations of hemodynamics, as well as for pre-surgical planning and training, testing the effectiveness of different interventions, or developing new surgical procedures. The current direct additive manufacturing techniques cannot simultaneously ensure the flexibility and transparency of models required by some applications. Therefore, casting techniques are presented to overcome these limitations and make the manufactured models suitable for in-vitro hemodynamic investigations, such as particle image velocimetry (PIV) measurements or medical imaging. Methods Two complex patient-specific AAA geometries were considered, and the related 3D models were fabricated through material casting. In particular, two casting approaches, i.e. lost molds and lost core casting, were investigated and tested to manufacture the deformable AAA models. The manufactured models were acquired by magnetic resonance, computed tomography (CT), ultrasound imaging, and PIV. In particular, CT scans were segmented to generate a volumetric reconstruction for each manufactured model that was compared to a reference model to assess the accuracy of the manufacturing process. Results Both lost molds and lost core casting techniques were successful in the manufacturing of the models. The lost molds casting allowed a high-level surface finish in the final 3D model. In this first case, the average signed distance between the manufactured model and the reference was (- 0.2 ± 0.2 ) mm. However, this approach was more expensive and time-consuming. On the other hand, the lost core casting was more affordable and allowed the reuse of the external molds to fabricate multiple copies of the same AAA model. In this second case, the average signed distance between the manufactured model and the reference was (0.1 ± 0.6 ) mm. However, the final model's surface finish quality was poorer compared to the model obtained by lost molds casting as the sealing of the outer molds was not as firm as the other casting technique. Conclusions Both lost molds and lost core casting techniques can be used for manufacturing patient-specific deformable AAA models suitable for hemodynamic investigations, including medical imaging and PIV.
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Affiliation(s)
- Maria Nicole Antonuccio
- BioCardioLab, Bioengineering Unit - Heart Hospital, Fondazione Toscana “G. Monasterio”, Massa, Italy
- Philips Research Paris, Suresnes, France
- Mines Saint-Étienne, Université Jean Monnet, INSERM, Saint-Étienne, France
| | - Emanuele Gasparotti
- BioCardioLab, Bioengineering Unit - Heart Hospital, Fondazione Toscana “G. Monasterio”, Massa, Italy
| | - Francesco Bardi
- BioCardioLab, Bioengineering Unit - Heart Hospital, Fondazione Toscana “G. Monasterio”, Massa, Italy
- Mines Saint-Étienne, Université Jean Monnet, INSERM, Saint-Étienne, France
- Predisurge, Grande Usine Creative 2, Saint-Etienne, France
| | - Angelo Monteleone
- Department of Radiology, Fondazione Toscana “G. Monasterio”, Massa, Italy
| | | | | | - Stéphane Avril
- Mines Saint-Étienne, Université Jean Monnet, INSERM, Saint-Étienne, France
| | - Simona Celi
- BioCardioLab, Bioengineering Unit - Heart Hospital, Fondazione Toscana “G. Monasterio”, Massa, Italy
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Ramaekers MJFG, Westenberg JJM, Adriaans BP, Nijssen EC, Wildberger JE, Lamb HJ, Schalla S. A clinician's guide to understanding aortic 4D flow MRI. Insights Imaging 2023; 14:114. [PMID: 37395817 DOI: 10.1186/s13244-023-01458-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 06/03/2023] [Indexed: 07/04/2023] Open
Abstract
Four-dimensional flow magnetic resonance imaging is an emerging technique which may play a role in diagnosis and risk-stratification of aortic disease. Some knowledge of flow dynamics and related parameters is necessary to understand and apply this technique in clinical workflows. The purpose of the current review is to provide a guide for clinicians to the basics of flow imaging, frequently used flow-related parameters, and their relevance in the context of aortic disease.Clinical relevance statement Understanding normal and abnormal aortic flow could improve clinical care in patients with aortic disease.
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Affiliation(s)
- Mitch J F G Ramaekers
- Department of Cardiology and Radiology and Nuclear Medicine, Maastricht University Medical Center +, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands.
- Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
| | - Jos J M Westenberg
- Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Bouke P Adriaans
- Department of Cardiology and Radiology and Nuclear Medicine, Maastricht University Medical Center +, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands
| | - Estelle C Nijssen
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center +, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Joachim E Wildberger
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center +, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Hildo J Lamb
- Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Simon Schalla
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands
- Department of Cardiology, Maastricht University Medical Center +, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
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Belkacemi D, Tahar Abbes M, Al-Rawi M, Al-Jumaily AM, Bachene S, Laribi B. Intraluminal Thrombus Characteristics in AAA Patients: Non-Invasive Diagnosis Using CFD. Bioengineering (Basel) 2023; 10:bioengineering10050540. [PMID: 37237609 DOI: 10.3390/bioengineering10050540] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/28/2023] Open
Abstract
Abdominal aortic aneurysms (AAA) continue to pose a high mortality risk despite advances in medical imaging and surgery. Intraluminal thrombus (ILT) is detected in most AAAs and may critically impact their development. Therefore, understanding ILT deposition and growth is of practical importance. To assist in managing these patients, the scientific community has been researching the relationship between intraluminal thrombus (ILT) and hemodynamic parameters wall shear stress (WSS) derivatives. This study analyzed three patient-specific AAA models reconstructed from CT scans using computational fluid dynamics (CFD) simulations and a pulsatile non-Newtonian blood flow model. The co-localization and relationship between WSS-based hemodynamic parameters and ILT deposition were examined. The results show that ILT tends to occur in regions of low velocity and time-averaged WSS (TAWSS) and high oscillation shear index (OSI), endothelial cell activation potential (ECAP), and relative residence time (RRT) values. ILT deposition areas were found in regions of low TAWSS and high OSI independently of the nature of flow near the wall characterized by transversal WSS (TransWSS). A new approach is suggested which is based on the estimation of CFD-based WSS indices specifically in the thinnest and thickest ILT areas of AAA patients; this approach is promising and supports the effectiveness of CFD as a decision-making tool for clinicians. Further research with a larger patient cohort and follow-up data are needed to confirm these findings.
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Affiliation(s)
- Djelloul Belkacemi
- Mechanics and Energetics Laboratory, Hassiba Ben Bouali University, Chlef 02000, Algeria
- Unité de Développement des Equipements Solaires UDES, CDER, Bousmail, Tipaza 42415, Algeria
| | - Miloud Tahar Abbes
- Mechanics and Energetics Laboratory, Hassiba Ben Bouali University, Chlef 02000, Algeria
| | - Mohammad Al-Rawi
- Center for Engineering and Industrial Design, Waikato Institute of Technology, Hamilton 3240, New Zealand
| | - Ahmed M Al-Jumaily
- Institute of Biomedical Technologies, Auckland University of Technology, Auckland 1010, New Zealand
| | - Sofiane Bachene
- Radiologie, Centre d'Imagerie Médicale, Cheraga, Algiers 16000, Algeria
| | - Boualem Laribi
- FIMA Laboratory, Department of Technology, Djilali Bounaama University, Khemis Miliana 44225, Algeria
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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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Association between blood flow pattern and rupture risk of abdominal aortic aneurysm based on computational fluid dynamics. Eur J Vasc Endovasc Surg 2022; 64:155-164. [PMID: 35605907 DOI: 10.1016/j.ejvs.2022.05.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 03/21/2022] [Accepted: 05/13/2022] [Indexed: 02/05/2023]
Abstract
OBJECTIVES This study aimed to derive a novel classification of blood flow pattern in AAA based on computational fluid dynamics, and determine the predicting value of flow pattern in abdominal aortic aneurysm (AAA) rupture. DESIGN Age, gender matched case-control study MATERIALS: Case patients were identified as those who underwent emergent endovascular or open repair due to ruptured or impending rupture AAA. Control patients were those age and gender matched AAA patients who were asymptomatic and confirmed unruptured from CTA images from the same period. METHODS Classification of blood flow pattern (Type I: non-helical main flow channel with multiple vortices; Type II: non-helical main flow channel with single vortices; Type III, helical main flow channel with helical vortices) and hemodynamic parameters [areas of low wall shear stress (A low WSS), aneurysm pressure drop (Δ pressure), etc.] were derived from computational fluid dynamic (CFD) analyses. Multivariate regression was used to determine independent risk factors of AAA rupture. The incremental discriminant and reclassification abilities for AAA rupture were compared among different models. RESULTS This study included 53 ruptured and 53 intact AAA patients. Ruptured AAA showed higher prevalence of type III flow pattern (60.38% vs. 15.09%, P<.001) compared to intact AAA. Type III flow pattern was associated with a significantly increased risk of aneurysm rupture (OR 10.22, 95%CI 3.43-30.49). Among all predicting models, combination of AAA diameter, hemodynamic parameters (A low WSS or Δ pressure) and flow pattern showed highest discriminant abilities in both overall population (concordance statistic [c-index] .862) and subgroup patients with AAAs <55mm (c-index .972). Compared to AAA diameter, adding flow pattern could significantly improve the reclassification abilities in both overall population (net reclassification index [NRI] .321; p<.001) and subgroup of AAAs < 55mm (NRI .732, P<.001). CONCLUSION Type III flow pattern was associated with a significantly increased risk of AAA rupture. Integration of blood flow pattern may improve the identification of high-risk aneurysms in both overall population and AAAs smaller than 55mm.
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Zambrano BA, Gharahi H, Lim CY, Lee W, Baek S. Association of vortical structures and hemodynamic parameters for regional thrombus accumulation in abdominal aortic aneurysms. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2022; 38:e3555. [PMID: 34859615 PMCID: PMC8858872 DOI: 10.1002/cnm.3555] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/18/2021] [Accepted: 11/27/2021] [Indexed: 05/08/2023]
Abstract
The intraluminal thrombus (ILT) has been shown to negatively impact the progression of the abdominal aortic aneurysms (AAAs). The formation of this thrombus layer has been connected to the local flow environment within AAAs, but the specific mechanisms leading to thrombus formation are still not fully understood. Our study investigated the association between vortical structures, near-wall hemodynamic metrics (e.g., time averaged wall shear stress (TAWSS) and oscillatory shear index (OSI)), and ILT accumulation in a longitudinal cohort of 14 AAAs (53 scans total). Vortices and hemodynamic parameters were estimated using hemodynamic simulations performed to each scan of each patient and compared to local 3D changes of ILT thickness between two consecutive scans (ΔILT). Results showed that vortices formed and remained strong and close to the lumen surface in AAAs without an ILT, while in AAAs with ILTs these detached from the lumen surface and dissipated nearby wall region where an increase in ILT thickness was observed. Although low TAWSS was observed in regions with and without ILT accumulation, an inverse correlation between ∆ILT and TAWSS was observed within the regions that experienced a thrombus growth. Our results support the idea that vortical structures might be playing a role modulating ILT accumulation into specific wall regions. Also, it submits the idea that the low TAWSS will be modulating the growth of thrombus within these preferred ILT accumulated regions.
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Affiliation(s)
- Byron A Zambrano
- J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, Texas, USA
| | - Hamidreza Gharahi
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan, USA
| | - Chae Young Lim
- Department of Statistics, Seoul National University, Seoul, Korea
| | - Whal Lee
- Department of Radiology, Seoul National University, Seoul, Korea
| | - Seungik Baek
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan, USA
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Sun W, Zheng J, Gao Y. Targeting Platelet Activation in Abdominal Aortic Aneurysm: Current Knowledge and Perspectives. Biomolecules 2022; 12:biom12020206. [PMID: 35204706 PMCID: PMC8961578 DOI: 10.3390/biom12020206] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 01/21/2022] [Accepted: 01/22/2022] [Indexed: 01/28/2023] Open
Abstract
Abdominal aortic aneurysm (AAA) is a potentially fatal vascular disease that involves complex multifactorial hemodynamic, thrombotic, inflammatory, and aortic wall remodeling processes. However, its mechanisms are incompletely understood. It has become increasingly clear that platelets are involved in pathological processes of vascular diseases beyond their role in hemostasis and thrombosis. Platelet activation with membrane receptors and secreted mediators promotes thrombus formation and the accumulation of inflammatory cells, which may play an important role in the development of AAA by destroying the structural integrity and stability of the vessel wall. Turbulent blood flow in aortic aneurysms promotes platelet activation and aggregation. Platelet count and heterogeneity are important predictive, diagnostic, and prognostic indicators of AAA. We summarize the relationship between platelet activation and AAA development and propose future research directions and possible clinical applications.
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Affiliation(s)
- Weiliang Sun
- Institute of Clinical Medicine Sciences, China-Japan Friendship Hospital, 2 Yinghua Dongjie, Chaoyang District, Beijing 100029, China;
| | - Jingang Zheng
- Department of Cardiology, China-Japan Friendship Hospital, 2 Yinghua Dongjie, Chaoyang District, Beijing 100029, China;
| | - Yanxiang Gao
- Department of Cardiology, China-Japan Friendship Hospital, 2 Yinghua Dongjie, Chaoyang District, Beijing 100029, China;
- Correspondence:
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Yin L, Zhang K, Sun Y, Liu Z. Nanoparticle-Assisted Diagnosis and Treatment for Abdominal Aortic Aneurysm. Front Med (Lausanne) 2021; 8:665846. [PMID: 34307401 PMCID: PMC8292633 DOI: 10.3389/fmed.2021.665846] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 06/03/2021] [Indexed: 11/16/2022] Open
Abstract
An abdominal aortic aneurysm (AAA) is a localized dilatation of the aorta related to the regional weakening of the wall structure, resulting in substantial morbidity and mortality with the aortic ruptures as complications. Ruptured AAA is a dramatic catastrophe, and aortic emergencies constitute one of the leading causes of acute death in older adults. AAA management has been centered on surgical repair of larger aneurysms to mitigate the risks of rupture, and curative early diagnosis and effective pharmacological treatments for this condition are still lacking. Nanoscience provided a possibility of more targeted imaging and drug delivery system. Multifunctional nanoparticles (NPs) may be modified with ligands or biomembranes to target agents' delivery to the lesion site, thus reducing systemic toxicity. Furthermore, NPs can improve drug solubility, circulation time, bioavailability, and efficacy after systemic administration. The varied judiciously engineered nano-biomaterials can exist stably in the blood vessels for a long time without being taken up by cells. Here, in this review, we focused on the NP application in the imaging and treatment of AAA. We hope to make an overview of NP-assisted diagnoses and therapy in AAA and discussed the potential of NP-assisted treatment.
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Affiliation(s)
- Li Yin
- Department of Vascular Surgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Kaijie Zhang
- Department of Cardiology, Sir Run Run Shaw Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Yuting Sun
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Zhenjie Liu
- Department of Vascular Surgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
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10
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Wang L, He L, Jia H, Lv R, Guo X, Yang C, Giddens DP, Samady H, Maehara A, Mintz GS, Yu B, Tang D. Optical Coherence Tomography-Based Patient-Specific Residual Multi-Thrombus Coronary Plaque Models With Fluid-Structure Interaction for Better Treatment Decisions: A Biomechanical Modeling Case Study. J Biomech Eng 2021; 143:1107994. [PMID: 33876192 DOI: 10.1115/1.4050911] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Indexed: 11/08/2022]
Abstract
Intracoronary thrombus from plaque erosion could cause fatal acute coronary syndrome (ACS). A conservative antithrombotic therapy has been proposed to treat ACS patients in lieu of stenting. It is speculated that the residual thrombus after aspiration thrombectomy would influence the prognosis of this treatment. However, biomechanical mechanisms affecting intracoronary thrombus remodeling and clinical outcome remain largely unknown. in vivo optical coherence tomography (OCT) data of a coronary plaque with two residual thrombi after antithrombotic therapy were acquired from an ACS patient with consent obtained. Three OCT-based fluid-structure interaction (FSI) models with different thrombus volumes, fluid-only, and structure-only models were constructed to simulate and compare the biomechanical interplay among blood flow, residual thrombus, and vessel wall mimicking different clinical situations. Our results showed that residual thrombus would decrease coronary volumetric flow rate by 9.3%, but elevate wall shear stress (WSS) by 29.4% and 75.5% at thrombi 1 and 2, respectively. WSS variations in a cardiac cycle from structure-only model were 12.1% and 13.5% higher at the two thrombus surfaces than those from FSI model. Intracoronary thrombi were subjected to compressive forces indicated by negative thrombus stress. Tandem intracoronary thrombus might influence coronary hemodynamics and solid mechanics differently. Computational modeling could be used to quantify biomechanical conditions under which patients could receive patient-specific treatment plan with optimized outcome after antithrombotic therapy. More patient studies with follow-up data are needed to continue the investigation and better understand mechanisms governing thrombus remodeling process.
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Affiliation(s)
- Liang Wang
- School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Luping He
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Haibo Jia
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Rui Lv
- School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Xiaoya Guo
- School of Science, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Chun Yang
- Network Technology Research Institute, China United Network Comm. Co., Ltd., Beijing 100048, China; Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609
| | - Don P Giddens
- Department of Medicine, Emory University School of Medicine, Atlanta, GA 30307; The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Habib Samady
- Department of Medicine, Emory University School of Medicine, Atlanta, GA 30307
| | - Akiko Maehara
- The Cardiovascular Research Foundation, Columbia University, New York, NY 10022
| | - Gary S Mintz
- The Cardiovascular Research Foundation, Columbia University, New York, NY 10022
| | - Bo Yu
- Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China
| | - Dalin Tang
- School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China;Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA 01609
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11
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Park MH, Qiu Y, Cao H, Yuan D, Li D, Jiang Y, Peng L, Zheng T. Influence of Hemodialysis Catheter Insertion on Hemodynamics in the Central Veins. J Biomech Eng 2020; 142:1075020. [PMID: 32110795 DOI: 10.1115/1.4046500] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Indexed: 02/05/2023]
Abstract
Central venous catheter (CVC) related thrombosis is a major cause of CVC dysfunction in patients under hemodialysis. The aim of our study was to investigate the impact of CVC insertion on hemodynamics in the central veins and to examine the changes in hemodynamic environments that may be related to thrombus formation due to the implantation of CVC. Patient-specific models of the central veins with and without CVC were reconstructed based on computed tomography images. Flow patterns in the veins were numerically simulated to obtain hemodynamic parameters such as time-averaged wall shear stress (TAWSS), oscillating shear index (OSI), relative residence time (RRT), and normalized transverse wall shear stress (transWSS) under pulsatile flow. The non-Newtonian effects of blood flow were also analyzed using the Casson model. The insertion of CVC caused significant changes in the hemodynamic environment in the central veins. A greater disturbance and increase of velocity were observed in the central veins after the insertion of CVC. As a result, TAWSS and transWSS were markedly increased, but most parts of OSI and RRT decreased. Newtonian assumption of blood flow would overestimate the increase in TAWSS after CVC insertion. High wall shear stress (WSS) and flow disturbance, especially the multidirectionality of the flow, induced by the CVC may be a key factor in initiating thrombosis after CVC insertion. Accordingly, approaches to decrease the flow disturbance during CVC insertion may help restrain the occurrence of thrombosis. More case studies with pre-operative and postoperative modeling and clinical follow-up need to be performed to verify these findings. Non-Newtonian blood flow assumption is recommended in computational fluid dynamics (CFD) simulations of veins with CVCs.
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Affiliation(s)
- Min-Hyuk Park
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China
| | - Yue Qiu
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China
| | - Haoyao Cao
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China
| | - Ding Yuan
- Department of Vascular Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Da Li
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China
| | - Yi Jiang
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China
| | - Liqing Peng
- Department of Radiology, West China Hospital, Sichuan University, No. 37, Guo Xue Xiang, Chengdu 610041, China
| | - Tinghui Zheng
- Department of Applied Mechanics, Sichuan University, Chengdu 610065, China
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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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13
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Bonfanti M, Franzetti G, Homer-Vanniasinkam S, Díaz-Zuccarini V, Balabani S. A Combined In Vivo, In Vitro, In Silico Approach for Patient-Specific Haemodynamic Studies of Aortic Dissection. Ann Biomed Eng 2020; 48:2950-2964. [PMID: 32929558 PMCID: PMC7723947 DOI: 10.1007/s10439-020-02603-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 09/02/2020] [Indexed: 12/30/2022]
Abstract
The optimal treatment of Type-B aortic dissection (AD) is still a subject of debate, with up to 50% of the cases developing late-term complications requiring invasive intervention. A better understanding of the patient-specific haemodynamic features of AD can provide useful insights on disease progression and support clinical management. In this work, a novel in vitro and in silico framework to perform personalised studies of AD, informed by non-invasive clinical data, is presented. A Type-B AD was investigated in silico using computational fluid dynamics (CFD) and in vitro by means of a state-of-the-art mock circulatory loop and particle image velocimetry (PIV). Both models not only reproduced the anatomical features of the patient, but also imposed physiologically-accurate and personalised boundary conditions. Experimental flow rate and pressure waveforms, as well as detailed velocity fields acquired via PIV, are extensively compared against numerical predictions at different locations in the aorta, showing excellent agreement. This work demonstrates how experimental and numerical tools can be developed in synergy to accurately reproduce patient-specific AD blood flow. The combined platform presented herein constitutes a powerful tool for advanced haemodynamic studies for a range of vascular conditions, allowing not only the validation of CFD models, but also clinical decision support, surgical planning as well as medical device innovation.
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Affiliation(s)
- Mirko Bonfanti
- grid.83440.3b0000000121901201Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), Department of Medical Physics and Biomedical Engineering, University College London, 43-45 Foley Street, London, W1W 7TS UK
| | - Gaia Franzetti
- grid.83440.3b0000000121901201Department of Mechanical Engineering, University College London, Torrington Place, London, WC1E 7JE UK
| | - Shervanthi Homer-Vanniasinkam
- grid.83440.3b0000000121901201Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), Department of Medical Physics and Biomedical Engineering, University College London, 43-45 Foley Street, London, W1W 7TS UK ,grid.83440.3b0000000121901201Department of Mechanical Engineering, University College London, Torrington Place, London, WC1E 7JE UK ,grid.415967.80000 0000 9965 1030Leeds Teaching Hospitals NHS Trust, Great George Street, Leeds, LS1 3EX UK
| | - Vanessa Díaz-Zuccarini
- grid.83440.3b0000000121901201Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), Department of Medical Physics and Biomedical Engineering, University College London, 43-45 Foley Street, London, W1W 7TS UK ,grid.83440.3b0000000121901201Department of Mechanical Engineering, University College London, Torrington Place, London, WC1E 7JE UK
| | - Stavroula Balabani
- grid.83440.3b0000000121901201Department of Mechanical Engineering, University College London, Torrington Place, London, WC1E 7JE UK
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Qiu Y, Wang Y, Fan Y, Peng L, Liu R, Zhao J, Yuan D, Zheng T. Role of intraluminal thrombus in abdominal aortic aneurysm ruptures: A hemodynamic point of view. Med Phys 2019; 46:4263-4275. [PMID: 31206182 DOI: 10.1002/mp.13658] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/27/2019] [Accepted: 06/05/2019] [Indexed: 02/05/2023] Open
Abstract
PURPOSE Intraluminal thrombus (ILTs) are found in most abdominal aortic aneurysms (AAAs) of clinically relevant size; however, the role of ILTs in AAA ruptures remains unclear. This study investigated the role of the presence and thickness of ILTs in AAA ruptures by analyzing the hemodynamic environment in ruptured AAAs (RAAAs). METHODS Three-dimensional reconstructions from computed tomography scans were performed, and 13 RAAA cases were categorized into a no-ILT group, a thin-layered ILT group (thickness < 3 mm), and a thick-layered ILT group. The hemodynamic features of the RAAAs were assessed using computational fluid dynamics simulation. RESULTS The thin- and thick-layered ILT groups showed significant differences in aneurysm diameters (P < 0.05). The three types of AAAs ruptured at different flow regions, with different hemodynamic features: (a) the no-ILT AAAs ruptured at regions of flow recirculation where velocity and wall shear stresses (WSSs) were close to zero; (b) the thin-layered ILT AAAs ruptured at sites at which the dominant flow impinged the wall; and (c) the thick-layered ILT AAAs ruptured at the border of the dominant flow channel and recirculation zone where the flow velocity and pressure changed dramatically. CONCLUSIONS Hemodynamic characteristics influence the rupture mechanisms of particular AAAs differently on the basis of the presence and thickness of ILTs. Recirculation flows and low WSSs may have negative effects by inducing local rupture or positive effects by promoting the formation of thin-layered ILTs. However, eccentrically located thick-layered ILTs may increase the rupture risk of small AAAs because of their location in the sac lumen, which results in chaotic flow patterns and rapid increases in flow resistance.
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Affiliation(s)
- Yue Qiu
- Department of Applied Mechanics, Sichuan University, Chengdu, 610065, China
| | - Yi Wang
- Department of Computer Science, Sichuan University of Science and Engineering, Zigong, Sichuan, 643000, China
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191, P. R. China
| | - Liqing Peng
- The Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Rong Liu
- Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong, China
| | - Jichun Zhao
- Department Vascular Surgery of West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Ding Yuan
- Department Vascular Surgery of West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Tinghui Zheng
- Department of Applied Mechanics, Sichuan University, Chengdu, 610065, China
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Salman HE, Ramazanli B, Yavuz MM, Yalcin HC. Biomechanical Investigation of Disturbed Hemodynamics-Induced Tissue Degeneration in Abdominal Aortic Aneurysms Using Computational and Experimental Techniques. Front Bioeng Biotechnol 2019; 7:111. [PMID: 31214581 PMCID: PMC6555197 DOI: 10.3389/fbioe.2019.00111] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 05/02/2019] [Indexed: 11/13/2022] Open
Abstract
Abdominal aortic aneurysm (AAA) is the dilatation of the aorta beyond 50% of the normal vessel diameter. It is reported that 4-8% of men and 0.5-1% of women above 50 years of age bear an AAA and it accounts for ~15,000 deaths per year in the United States alone. If left untreated, AAA might gradually expand until rupture; the most catastrophic complication of the aneurysmal disease that is accompanied by a striking overall mortality of 80%. The precise mechanisms leading to AAA rupture remains unclear. Therefore, characterization of disturbed hemodynamics within AAAs will help to understand the mechanobiological development of the condition which will contribute to novel therapies for the condition. Due to geometrical complexities, it is challenging to directly quantify disturbed flows for AAAs clinically. Two other approaches for this investigation are computational modeling and experimental flow measurement. In computational modeling, the problem is first defined mathematically, and the solution is approximated with numerical techniques to get characteristics of flow. In experimental flow measurement, once the setup providing physiological flow pattern in a phantom geometry is constructed, velocity measurement system such as particle image velocimetry (PIV) enables characterization of the flow. We witness increasing number of applications of these complimentary approaches for AAA investigations in recent years. In this paper, we outline the details of computational modeling procedures and experimental settings and summarize important findings from recent studies, which will help researchers for AAA investigations and rupture mechanics.
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Affiliation(s)
| | - Burcu Ramazanli
- Department of Mechanical Engineering, Middle East Technical University, Ankara, Turkey
| | - Mehmet Metin Yavuz
- Department of Mechanical Engineering, Middle East Technical University, Ankara, Turkey
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Wee I, Ong CW, Syn N, Choong A. Computational Fluid Dynamics and Aortic Dissections: Panacea or Panic? VASCULAR AND ENDOVASCULAR REVIEW 2018. [DOI: 10.15420/ver.2018.8.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
This paper reviews the methodology, benefits and limitations associated with computational flow dynamics (CFD) in the field of vascular surgery. Combined with traditional imaging of the vasculature, CFD simulation enables accurate characterisation of real-time physiological and haemodynamic parameters such as wall shear stress. This enables vascular surgeons to understand haemodynamic changes in true and false lumens, and exit and re-entry tears. This crucial information may facilitate triaging decisions. Furthermore, CFD can be used to assess the impact of stent graft treatment, as it provides a haemodynamic account of what may cause procedure-related complications. Efforts to integrate conventional imaging, individual patient data and CFD are paramount to its success, given its potential to replace traditional registry-based, population-averaged data. Nonetheless, methodological limitations must be addressed before clinical implementation. This must be accompanied by further research with large sample sizes, to establish the association between haemodynamic patterns as observed by CFD and progression of aortic dissection.
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Affiliation(s)
- Ian Wee
- SingVaSC, Singapore Vascular Surgical Collaborative; Yong Loo Lin School of Medicine, National University of Singapore
| | - Chi Wei Ong
- SingVaSC, Singapore Vascular Surgical Collaborative; Department of Biomedical Engineering, National University of Singapore
| | - Nicholas Syn
- SingVaSC, Singapore Vascular Surgical Collaborative; Yong Loo Lin School of Medicine, National University of Singapore
| | - Andrew Choong
- SingVaSC, Singapore Vascular Surgical Collaborative; Cardiovascular Research Institute, National University of Singapore; Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore; Division of Vascular Surgery, National University Heart Centre, Singapore
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17
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Computational Fluid Dynamics Modeling of the Human Pulmonary Arteries with Experimental Validation. Ann Biomed Eng 2018; 46:1309-1324. [PMID: 29786774 DOI: 10.1007/s10439-018-2047-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 05/10/2018] [Indexed: 12/22/2022]
Abstract
Pulmonary hypertension (PH) is a chronic progressive disease characterized by elevated pulmonary arterial pressure, caused by an increase in pulmonary arterial impedance. Computational fluid dynamics (CFD) can be used to identify metrics representative of the stage of PH disease. However, experimental validation of CFD models is often not pursued due to the geometric complexity of the model or uncertainties in the reproduction of the required flow conditions. The goal of this work is to validate experimentally a CFD model of a pulmonary artery phantom using a particle image velocimetry (PIV) technique. Rapid prototyping was used for the construction of the patient-specific pulmonary geometry, derived from chest computed tomography angiography images. CFD simulations were performed with the pulmonary model with a Reynolds number matching those of the experiments. Flow rates, the velocity field, and shear stress distributions obtained with the CFD simulations were compared to their counterparts from the PIV flow visualization experiments. Computationally predicted flow rates were within 1% of the experimental measurements for three of the four branches of the CFD model. The mean velocities in four transversal planes of study were within 5.9 to 13.1% of the experimental mean velocities. Shear stresses were qualitatively similar between the two methods with some discrepancies in the regions of high velocity gradients. The fluid flow differences between the CFD model and the PIV phantom are attributed to experimental inaccuracies and the relative compliance of the phantom. This comparative analysis yielded valuable information on the accuracy of CFD predicted hemodynamics in pulmonary circulation models.
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Lashkarinia SS, Piskin S, Bozkaya TA, Salihoglu E, Yerebakan C, Pekkan K. Computational Pre-surgical Planning of Arterial Patch Reconstruction: Parametric Limits and In Vitro Validation. Ann Biomed Eng 2018; 46:1292-1308. [PMID: 29761422 PMCID: PMC6097742 DOI: 10.1007/s10439-018-2043-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 05/04/2018] [Indexed: 02/06/2023]
Abstract
Surgical treatment of congenital heart disease (CHD) involves complex vascular reconstructions utilizing artificial and native surgical materials. A successful surgical reconstruction achieves an optimal hemodynamic profile through the graft in spite of the complex post-operative vessel growth pattern and the altered pressure loading. This paper proposes a new in silico patient-specific pre-surgical planning framework for patch reconstruction and investigates its computational feasibility. The proposed protocol is applied to the patch repair of main pulmonary artery (MPA) stenosis in the Tetralogy of Fallot CHD template. The effects of stenosis grade, the three-dimensional (3D) shape of the surgical incision and material properties of the artificial patch are investigated. The release of residual stresses due to the surgical incision and the extra opening of the incision gap for patch implantation are simulated through a quasi-static finite-element vascular model with shell elements. Implantation of different unloaded patch shapes is simulated. The patched PA configuration is pressurized to the physiological post-operative blood pressure levels of 25 and 45 mmHg and the consequent post-operative stress distributions and patched artery shapes are computed. Stress–strain data obtained in-house, through the biaxial tensile tests for the mechanical properties of common surgical patch materials, Dacron, Polytetrafluoroethylene, human pericardium and porcine xenopericardium, are employed to represent the mechanical behavior of the patch material. Finite-element model is experimentally validated through the actual patch surgery reconstructions performed on the 3D printed anatomical stenosis replicas. The post-operative recovery of the initially narrowed lumen area and post-op tortuosity are quantified for all modeled cases. A computational fluid dynamics solver is used to evaluate post-operative pressure drop through the patch-reconstructed outflow tract. According to our findings, the shorter incisions made at the throat result in relatively low local peak stress values compared to other patch design alternatives. Longer cut and double patch cases are the most effective in repairing the initial stenosis level. After the patch insertion, the pressure drop in the artery due to blood flow decreases from 9.8 to 1.35 mmHg in the conventional surgical configuration. These results are in line with the clinical experience where a pressure gradient at or above 50 mmHg through the MPA can be an indication to intervene. The main strength of the proposed pre-surgical planning framework is its capability to predict the intra-operative and post-operative 3D vascular shape changes due to intramural pressure, cut length and configuration, for both artificial and native patch materials.
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Affiliation(s)
- S Samaneh Lashkarinia
- Department of Mechanical Engineering, Koc University, Rumeli Feneri Kampüsü, Sarıyer, Istanbul, Turkey
| | - Senol Piskin
- Department of Mechanical Engineering, Koc University, Rumeli Feneri Kampüsü, Sarıyer, Istanbul, Turkey
- Department of Mechanical Engineering, University of Texas at San Antonio, San Antonio, TX, USA
| | - Tijen A Bozkaya
- Department of Cardiovascular Surgery, Koc University Medical School, Istanbul, Turkey
| | - Ece Salihoglu
- Department of Cardiovascular Surgery, Istanbul Medipol University, Istanbul, Turkey
| | - Can Yerebakan
- Cardiovascular Surgery, Children's National Heart Institute, The George Washington University School of Medicine, Washington, DC, USA
| | - Kerem Pekkan
- Department of Mechanical Engineering, Koc University, Rumeli Feneri Kampüsü, Sarıyer, Istanbul, Turkey.
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van de Velde L, Donselaar EJ, Groot Jebbink E, Boersen JT, Lajoinie GP, de Vries JPP, Zeebregts CJ, Versluis M, Reijnen MM. Partial renal coverage in endovascular aneurysm repair causes unfavorable renal flow patterns in an infrarenal aneurysm model. J Vasc Surg 2018; 67:1585-1594. [DOI: https:/doi.org/10.1016/j.jvs.2017.05.092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
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20
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Kemmerling EMC, Peattie RA. Abdominal Aortic Aneurysm Pathomechanics: Current Understanding and Future Directions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1097:157-179. [DOI: 10.1007/978-3-319-96445-4_8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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21
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Partial renal coverage in endovascular aneurysm repair causes unfavorable renal flow patterns in an infrarenal aneurysm model. J Vasc Surg 2017; 67:1585-1594. [PMID: 28893490 DOI: 10.1016/j.jvs.2017.05.092] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 05/01/2017] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To achieve an optimal sealing zone during endovascular aneurysm repair, the intended positioning of the proximal end of the endograft fabric should be as close as possible to the most caudal edge of the renal arteries. Some endografts exhibit a small offset between the radiopaque markers and the proximal fabric edge. Unintended partial renal artery coverage may thus occur. This study investigated the consequences of partial coverage on renal flow patterns and wall shear stress (WSS). METHODS In vitro models of an abdominal aortic aneurysm were used to visualize pulsatile flow using two-dimensional particle image velocimetry under physiologic resting conditions. One model served as control and two models were stented with an Endurant endograft (Medtronic Inc, Minneapolis, Minn), one without and one with partial renal artery coverage with 1.3 mm of stent fabric extending beyond the marker (16% area coverage). The magnitude and oscillation of WSS, relative residence time, and backflow in the renal artery were analyzed. RESULTS In both stented models, a region along the caudal renal artery wall presented with low and oscillating WSS, not present in the control model. A region with very low WSS (<0.1 Pa) was present in the model with partial coverage over a length of 7 mm compared with a length of 2 mm in the model without renal coverage. Average renal backflow area percentage in the renal artery incrementally increased from control (0.9%) to the stented model without (6.4%) and with renal coverage (18.8%). CONCLUSIONS In this flow model, partial renal coverage after endovascular aneurysm repair causes low and marked oscillations in WSS, potentially promoting atherosclerosis and subsequent renal artery stenosis. Awareness of the device-dependent offset between the fabric edge and the radiopaque markers is therefore important in endovascular practice.
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Roloff C, Berg P, Redel T, Janiga G, Thevenin D. Tomographic particle image velocimetry for the validation of hemodynamic simulations in an intracranial aneurysm. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2017:1340-1343. [PMID: 29060124 DOI: 10.1109/embc.2017.8037080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Image-based blood flow simulations can provide detailed hemodynamic information in diseased vessels such as intracranial aneurysms. However, validation is essential to evaluate the accuracy of these computations and further improve their acceptance among physicians. In this regard, tomographic particle image velocimetry was used to measure the flow characteristics in a patient specific aneurysm phantom model. Additionally, computational fluid dynamics (CFD) simulations were carried out using a well accepted commercial software package and a clinical research prototype, respectively. The comparison between in-vitro measurement and in-silico computations reveals a good qualitative agreement. Further, computations based on classical CFD agreed well with results from a clinical research prototype. Hence, the results of this study demonstrate the usability of numerical methods to obtain realistic blood flow predictions in a clinical context.
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Frolov SV, Sindeev SV, Liepsch D, Balasso A. Experimental and CFD flow studies in an intracranial aneurysm model with Newtonian and non-Newtonian fluids. Technol Health Care 2017; 24:317-33. [PMID: 26835725 DOI: 10.3233/thc-161132] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND According to the clinical data, flow conditions play a major role in the genesis of intracranial aneurysms. The disorder of the flow structure is the cause of damage of the inner layer of the vessel wall, which leads to the development of cerebral aneurysms. Knowledge of the alteration of the flow field in the aneurysm region is important for treatment. OBJECTIVE The aim is to study quantitatively the flow structure in an patient-specific aneurysm model of the internal carotid artery using both experimental and computational fluid dynamics (CFD) methods with Newtonian and non-Newtonian fluids. METHODS A patient-specific geometry of aneurysm of the internal carotid artery was used. Patient data was segmented and smoothed to obtain geometrical model. An elastic true-to-scale silicone model was created with stereolithography. For initial investigation of the blood flow, the flow was visualized by adding particles into the silicone model. The precise flow velocity measurements were done using 1D Laser Doppler Anemometer with a spatial resolution of 50 μ m and a temporal resolution of 1 ms. The local velocity measurements were done at a distance of 4 mm to each other. A fluid with non-Newtonian properties was used in the experiment. The CFD simulations for unsteady-state problem were done using constructed hexahedral mesh for Newtonian and non-Newtonian fluids. RESULTS Using 1D laser Doppler Anemometer the minimum velocity magnitude at the end of systole -0.01 m/s was obtained in the aneurysm dome while the maximum velocity 1 m/s was at the center of the outlet segment. On central cross section of the aneurysm the maximum velocity value is only 20% of the average inlet velocity. The average velocity on the cross-section is only 11% of the inlet axial velocity. Using the CFD simulation the wall shear stresses for Newtonian and non-Newtonian fluid at the end of systolic phase (t= 0.25 s) were computed. The wall shear stress varies from 3.52 mPa (minimum value) to 10.21 Pa (maximum value) for the Newtonian fluid. For the non-Newtonian fluid the wall shear stress minimum is 2.94 mPa; the maximum is 9.14 Pa. The lowest value of the wall shear stress for both fluids was obtained at the dome of the aneurysm while the highest wall shear stress was at the beginning of the outlet segment. The vortex in the aneurysm region is unstable during the cardiac cycle. The clockwise rotation of the streamlines at the inlet segment for Newtonian and non-Newtonian fluid is shown. CONCLUSION The results of the present study are in agreement with the hemodynamics theory of aneurysm genesis. Low value of wall shear stress is observed at the aneurysm dome which can cause a rupture of an aneurysm.
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Affiliation(s)
- S V Frolov
- Department of Biomedical Engineering, Tambov State Technical University, Tambov, Russia
| | - S V Sindeev
- Department of Biomedical Engineering, Tambov State Technical University, Tambov, Russia
| | - D Liepsch
- Department of Mechanical Engineering, Munich University of Applied Sciences, Munich, Germany
| | - A Balasso
- Department of Neuroradiology, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
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Endoleak Assessment Using Computational Fluid Dynamics and Image Processing Methods in Stented Abdominal Aortic Aneurysm Models. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2016; 2016:9567294. [PMID: 27660648 PMCID: PMC5021907 DOI: 10.1155/2016/9567294] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 07/02/2016] [Accepted: 08/09/2016] [Indexed: 11/18/2022]
Abstract
Endovascular aortic aneurysm repair (EVAR) is a predominant surgical procedure to reduce the risk of aneurysm rupture in abdominal aortic aneurysm (AAA) patients. Endoleak formation, which eventually requires additional surgical reoperation, is a major EVAR complication. Understanding the etiology and evolution of endoleak from the hemodynamic perspective is crucial to advancing the current posttreatments for AAA patients who underwent EVAR. Therefore, a comprehensive flow assessment was performed to investigate the relationship between endoleak and its surrounding pathological flow fields through computational fluid dynamics and image processing. Six patient-specific models were reconstructed, and the associated hemodynamics in these models was quantified three-dimensionally to calculate wall stress. To provide a high degree of clinical relevance, the mechanical stress distribution calculated from the models was compared with the endoleak positions identified from the computed tomography images of patients through a series of imaging processing methods. An endoleak possibly forms in a location with high local wall stress. An improved stent graft (SG) structure is conceived accordingly by increasing the mechanical strength of the SG at peak wall stress locations. The presented analytical paradigm, as well as numerical analysis using patient-specific models, may be extended to other common human cardiovascular surgeries.
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Aramburu J, Antón R, Borro D, Rivas A, Larraona GS, Ramos JC, Finol EA. A methodology for assessing local bifurcated blood vessel shape variations. Biomed Phys Eng Express 2016. [DOI: 10.1088/2057-1976/2/1/015001] [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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Tong J, Holzapfel GA. Structure, Mechanics, and Histology of Intraluminal Thrombi in Abdominal Aortic Aneurysms. Ann Biomed Eng 2015; 43:1488-501. [DOI: 10.1007/s10439-015-1332-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 05/06/2015] [Indexed: 01/08/2023]
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27
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Raptis A, Xenos M, Dimas S, Giannoukas A, Labropoulos N, Bluestein D, Matsagkas MI. Effect of macroscale formation of intraluminal thrombus on blood flow in abdominal aortic aneurysms. Comput Methods Biomech Biomed Engin 2015; 19:84-92. [DOI: 10.1080/10255842.2014.989389] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Gallo D, Gülan U, Di Stefano A, Ponzini R, Lüthi B, Holzner M, Morbiducci U. Analysis of thoracic aorta hemodynamics using 3D particle tracking velocimetry and computational fluid dynamics. J Biomech 2014; 47:3149-55. [DOI: 10.1016/j.jbiomech.2014.06.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 06/05/2014] [Accepted: 06/12/2014] [Indexed: 11/24/2022]
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Antón R, Chen CY, Hung MY, Finol E, Pekkan K. Experimental and computational investigation of the patient-specific abdominal aortic aneurysm pressure field. Comput Methods Biomech Biomed Engin 2014; 18:981-992. [DOI: 10.1080/10255842.2013.865024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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