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He F, Wang X, Hua L, Guo T. Numerical simulation of hemodynamics in patient-specific pulmonary artery stenosis. Biomed Mater Eng 2023; 34:427-437. [PMID: 37125542 DOI: 10.3233/bme-222523] [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] [Indexed: 05/02/2023]
Abstract
BACKGROUND The incidence rate of pulmonary artery stenosis is increasing year by year and its numerical simulation has become a key project of biomedical engineering. OBJECTIVE The purpose of this work is to study the changes of hemodynamic parameters in patient-specific pulmonary artery stenosis. METHODS A pulmonary artery stenosis model is established based on patient-specific computed tomography (CT) images. According to the actual anatomy of patient-specific pulmonary artery stenosis, the stenosis area is simulated using a porous medium to study its hemodynamic changes. The computational fluid dynamics (CFD) method is used to simulate the hemodynamic changes of pulmonary artery stenosis, and to explore the mechanical characteristics between blood flow and vessel wall. RESULTS The results suggest that the blood pressures of arterial branches increase and the pressure drop at both ends of the stenosis is higher. There is a high flow rate and wall shear stress at the stenosis. CONCLUSION This study shows that the hemodynamic model of pulmonary artery stenosis can be accurately reconstructed by achieving numerical simulation of the local stenosis through CT images, and this work has important implications for improving the confidence of clinical diagnosis and treatment of pulmonary artery diseases.
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Affiliation(s)
- Fan He
- School of Science, Beijing University of Civil Engineering and Architecture, Beijing, China
| | - Xinyu Wang
- School of Science, Beijing University of Civil Engineering and Architecture, Beijing, China
| | - Lu Hua
- Thrombosis Center, National Clinical Research Center for Cardiovascular Diseases, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Tingting Guo
- Thrombosis Center, National Clinical Research Center for Cardiovascular Diseases, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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2
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Pourmodheji R, Jiang Z, Tossas-Betancourt C, Dorfman AL, Figueroa CA, Baek S, Lee LC. Computational modelling of multi-temporal ventricular-vascular interactions during the progression of pulmonary arterial hypertension. J R Soc Interface 2022; 19:20220534. [PMID: 36415977 PMCID: PMC9682304 DOI: 10.1098/rsif.2022.0534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 11/02/2022] [Indexed: 11/25/2022] Open
Abstract
A computational framework is developed to consider the concurrent growth and remodelling (G&R) processes occurring in the large pulmonary artery (PA) and right ventricle (RV), as well as ventricular-vascular interactions during the progression of pulmonary arterial hypertension (PAH). This computational framework couples the RV and the proximal PA in a closed-loop circulatory system that operates in a short timescale of a cardiac cycle, and evolves over a long timescale due to G&R processes in the PA and RV. The framework predicts changes in haemodynamics (e.g. 68.2% increase in mean PA pressure), RV geometry (e.g. 38% increase in RV end-diastolic volume) and PA tissue microstructure (e.g. 90% increase in collagen mass) that are consistent with clinical and experimental measurements of PAH. The framework also predicts that a reduction in RV contractility is associated with long-term RV chamber dilation, a common biomarker observed in the late-stage PAH. Sensitivity analyses on the G&R rate constants show that large PA stiffening (both short and long term) is affected by RV remodelling more than the reverse. This framework can serve as a foundation for the future development of a more predictive and comprehensive cardiovascular G&R model with realistic heart and vascular geometries.
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Affiliation(s)
- Reza Pourmodheji
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
| | - Zhenxiang Jiang
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
| | | | - Adam L. Dorfman
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
| | - C. Alberto Figueroa
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Seungik Baek
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
| | - Lik-Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
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3
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Conijn M, Krings GJ. Understanding stenotic pulmonary arteries: Can computational fluid dynamics help us out? PROGRESS IN PEDIATRIC CARDIOLOGY 2022. [DOI: 10.1016/j.ppedcard.2021.101452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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4
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Lee EH, Baek S. Plasticity and Enzymatic Degradation Coupled With Volumetric Growth in Pulmonary Hypertension Progression. J Biomech Eng 2021; 143:111012. [PMID: 34076235 PMCID: PMC8299811 DOI: 10.1115/1.4051383] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 05/27/2021] [Indexed: 12/16/2022]
Abstract
Pulmonary hypertension (PH) is one of the least understood and highly elusive cardiovascular conditions associated with elevated pulmonary arterial pressure. Although the disease mechanisms are not completely understood, evidence has accumulated from human and animal studies that irreversible processes of pulmonary arterial wall damage, compensated by stress-mediated growth, play critical roles in eliciting the mechanisms of disease progression. The aim of this study is to develop a thermodynamic modeling structure of the pulmonary artery to consider coupled plastic-degradation-growth irreversible processes to investigate the mechanical roles of the dissipative phenomena in the disease progression. The proposed model performs a model parameter study of plastic deformation and degradation processes coupled with dissipative growth subjected to elevated pulmonary arterial pressure and computationally generates in silico simulations of PH progression using the clinical features of PH, found in human morphological and mechanical data. The results show that considering plastic deformation can provide a much better fitting of the ex vivo inflation tests than a widely used pure hyperelastic model in higher pressure conditions. In addition, the parameter sensitivity study illustrates that arterial damage and growth cause the increased stiffness, and the full simulation (combining elastic-plastic-degradation-growth models) reveals a key postpathological recovery process of compensating vessel damage by vascular adaptation by reducing the rate of vessel dilation and mediating vascular wall stress. Finally, the simulation results of luminal enlargement, arterial thickening, and arterial stiffness for an anisotropic growth are found to be close to the values from the literature.
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Affiliation(s)
- Eun-Ho Lee
- School of Mechanical Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, South Korea; Department of Smart Fab. Technology, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, South Korea
| | - Seungik Baek
- Department of Mechanical Engineering, Michigan State University, 2457 Engineering Building, East Lansing, MI 488424
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5
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Gopalan D, Gibbs JSR. From Early Morphometrics to Machine Learning-What Future for Cardiovascular Imaging of the Pulmonary Circulation? Diagnostics (Basel) 2020; 10:diagnostics10121004. [PMID: 33255668 PMCID: PMC7760106 DOI: 10.3390/diagnostics10121004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 11/19/2020] [Accepted: 11/24/2020] [Indexed: 02/07/2023] Open
Abstract
Imaging plays a cardinal role in the diagnosis and management of diseases of the pulmonary circulation. Behind the picture itself, every digital image contains a wealth of quantitative data, which are hardly analysed in current routine clinical practice and this is now being transformed by radiomics. Mathematical analyses of these data using novel techniques, such as vascular morphometry (including vascular tortuosity and vascular volumes), blood flow imaging (including quantitative lung perfusion and computational flow dynamics), and artificial intelligence, are opening a window on the complex pathophysiology and structure-function relationships of pulmonary vascular diseases. They have the potential to make dramatic alterations to how clinicians investigate the pulmonary circulation, with the consequences of more rapid diagnosis and a reduction in the need for invasive procedures in the future. Applied to multimodality imaging, they can provide new information to improve disease characterization and increase diagnostic accuracy. These new technologies may be used as sophisticated biomarkers for risk prediction modelling of prognosis and for optimising the long-term management of pulmonary circulatory diseases. These innovative techniques will require evaluation in clinical trials and may in themselves serve as successful surrogate end points in trials in the years to come.
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Affiliation(s)
- Deepa Gopalan
- Imperial College Healthcare NHS Trust, London W12 0HS, UK
- Imperial College London, London SW7 2AZ, UK;
- Cambridge University Hospital, Cambridge CB2 0QQ, UK
- Correspondence: ; Tel.: +44-77-3000-7780
| | - J. Simon R. Gibbs
- Imperial College London, London SW7 2AZ, UK;
- National Heart & Lung Institute, Imperial College London, London SW3 6LY, UK
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6
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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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7
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Frank BS, Ivy DD. Diagnosis, Evaluation and Treatment of Pulmonary Arterial Hypertension in Children. CHILDREN (BASEL, SWITZERLAND) 2018; 5:E44. [PMID: 29570688 PMCID: PMC5920390 DOI: 10.3390/children5040044] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 02/28/2018] [Accepted: 03/16/2018] [Indexed: 12/23/2022]
Abstract
Pulmonary Hypertension (PH), the syndrome of elevated pressure in the pulmonary arteries, is associated with significant morbidity and mortality for affected children. PH is associated with a wide variety of potential underlying causes, including cardiac, pulmonary, hematologic and rheumatologic abnormalities. Regardless of the cause, for many patients the natural history of PH involves progressive elevation in pulmonary arterial resistance and pressure, right ventricular dysfunction, and eventually heart failure. In recent years, a number of pulmonary arterial hypertension (PAH)-targeted therapies have become available to reduce pulmonary artery pressure and improve outcome. A growing body of evidence in both the adult and pediatric literature demonstrates enhanced quality of life, functional status, and survival among treated patients. This review provides a description of select etiologies of PH seen in pediatrics and an update on the most recent data pertaining to evaluation and management of children with PH/PAH. The available evidence for specific classes of PAH-targeted therapies in pediatrics is additionally discussed.
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Affiliation(s)
- Benjamin S Frank
- Section of Cardiology, Department of Pediatrics, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO 80045, USA.
| | - D Dunbar Ivy
- Section of Cardiology, Department of Pediatrics, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO 80045, USA.
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D'Souza GA, Taylor MD, Banerjee RK. Evaluation of pulmonary artery wall properties in congenital heart disease patients using cardiac magnetic resonance. PROGRESS IN PEDIATRIC CARDIOLOGY 2017. [DOI: 10.1016/j.ppedcard.2017.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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9
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Xi C, Latnie C, Zhao X, Tan JL, Wall ST, Genet M, Zhong L, Lee LC. Patient-Specific Computational Analysis of Ventricular Mechanics in Pulmonary Arterial Hypertension. J Biomech Eng 2017; 138:2551745. [PMID: 27589906 DOI: 10.1115/1.4034559] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Indexed: 11/08/2022]
Abstract
Patient-specific biventricular computational models associated with a normal subject and a pulmonary arterial hypertension (PAH) patient were developed to investigate the disease effects on ventricular mechanics. These models were developed using geometry reconstructed from magnetic resonance (MR) images, and constitutive descriptors of passive and active mechanics in cardiac tissues. Model parameter values associated with ventricular mechanical properties and myofiber architecture were obtained by fitting the models with measured pressure-volume loops and circumferential strain calculated from MR images using a hyperelastic warping method. Results show that the peak right ventricle (RV) pressure was substantially higher in the PAH patient (65 mmHg versus 20 mmHg), who also has a significantly reduced ejection fraction (EF) in both ventricles (left ventricle (LV): 39% versus 66% and RV: 18% versus 64%). Peak systolic circumferential strain was comparatively lower in both the left ventricle (LV) and RV free wall (RVFW) of the PAH patient (LV: -6.8% versus -13.2% and RVFW: -2.1% versus -9.4%). Passive stiffness, contractility, and myofiber stress in the PAH patient were all found to be substantially increased in both ventricles, whereas septum wall in the PAH patient possessed a smaller curvature than that in the LV free wall. Simulations using the PAH model revealed an approximately linear relationship between the septum curvature and the transseptal pressure gradient at both early-diastole and end-systole. These findings suggest that PAH can induce LV remodeling, and septum curvature measurements may be useful in quantifying transseptal pressure gradient in PAH patients.
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Affiliation(s)
- Ce Xi
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824-1226
| | - Candace Latnie
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824-1226
| | - Xiaodan Zhao
- National Heart Center Singapore, Singapore, Singapore 169609
| | - Ju Le Tan
- National Heart Center Singapore, Singapore, Singapore 169609
| | | | - Martin Genet
- LMS, École Polytechnique, CNRS, Université Paris-Saclay; Inria, Université Paris-Saclay, Palaiseau 91128, France
| | - Liang Zhong
- National Heart Center Singapore, Singapore, Singapore 169609;Duke-NUS Medical School, Singapore, Singapore 169857
| | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824-1226 e-mail:
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10
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Ma J, Yu N, Shen C, Wang Z, He T, Guo YM. A three-dimensional approach for identifying small pulmonary vessels in smokers. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2017; 25:391-402. [PMID: 28157121 DOI: 10.3233/xst-16216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
BACKGROUND This study aims to develop a computerized scheme that utilizes a differential geometric approach to identify pulmonary vessels and then evaluate the performance of the scheme on the CT images of heavy smokers. METHODS The scheme consists of two primary steps to segment entire lung vascular tree and identify the number of pulmonary vessels in a cross section. The scheme performance including accuracy, consistency, and efficiency was assessed using 102 chest CT scans. Further assessment was performed on the relationship between pulmonary vessels and the extent of emphysema as well as pulmonary artery alteration. RESULTS The mean number of vessels in the cross section at the 5th generation was 17.84±4.74 and 17.23±4.85 assessed by computerized scheme and radiologists, respectively, which are significantly different (t = 2.12, p = 0.055). The results were consistent with those obtained by using a semi-automatic tool (r = 0.75, p = 0.01). In addition, in the 5th generation, the mean number of vessels was inversely related to the percentage of the low attenuation area (r = -0.704, p = 0.000), the mean lumen area of pulmonary vessel was inversely related to the mean value of main pulmonary artery diameter (r = -0.617, p = 0.000). The computational time of segmenting vessels was 6.50±0.02 seconds, which is much less than the average 8 minutes of the time spent by radiologists using the semi-automatic tool. CONCLUSION Applying the computerized scheme yields reasonable performance on the segmentation of pulmonary vessels. The alteration of pulmonary vessels may reflect the presence of pulmonary hypertension, as well as the extent of emphysema.
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Affiliation(s)
- Junchao Ma
- Department of Radiology, The Affiliated Hospital of Shaanxi University of traditional Chinese Medicine, Xian yang, China
| | - Nan Yu
- Department of Radiology, The Affiliated Hospital of Shaanxi University of traditional Chinese Medicine, Xian yang, China
| | - Cong Shen
- Department of Radiology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Zhimin Wang
- Department of Radiology, Tumor Hospital of Gansu Province, Lanzhou, China
| | - Taiping He
- Department of Radiology, The Affiliated Hospital of Shaanxi University of traditional Chinese Medicine, Xian yang, China
| | - You-Min Guo
- Department of Radiology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
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Abstract
The prevalence of PH is increasing in the pediatric population, because of improved recognition and increased survival of patients, and remains a significant cause of morbidity and mortality. Recent studies have improved the understanding of pediatric PH, but management remains challenging because of a lack of evidence-based clinical trials. The growing contribution of developmental lung disease requires dedicated research to explore the use of existing therapies as well as the creation of novel therapies. Adequate study of pediatric PH will require multicenter collaboration due to the small numbers of patients, multifactorial disease causes, and practice variability.
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Affiliation(s)
- Dunbar Ivy
- Section of Pediatric Cardiology, Children's Hospital Colorado, University of Colorado School of Medicine, 13123 East 16th Avenue, B100, Aurora, CO 80045, USA.
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12
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Comparison of pulmonary arterial wall properties between a congenital heart disease patient and a normal subject using in vivo pressure–diameter measurements: A feasibility study. PROGRESS IN PEDIATRIC CARDIOLOGY 2016. [DOI: 10.1016/j.ppedcard.2015.12.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Kheyfets V, Thirugnanasambandam M, Rios L, Evans D, Smith T, Schroeder T, Mueller J, Murali S, Lasorda D, Spotti J, Finol E. The role of wall shear stress in the assessment of right ventricle hydraulic workload. Pulm Circ 2015; 5:90-100. [PMID: 25992274 DOI: 10.1086/679703] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 07/22/2014] [Indexed: 11/03/2022] Open
Abstract
Pulmonary hypertension (PH) is a devastating disease affecting approximately 15-50 people per million, with a higher incidence in women. PH mortality is mostly attributed to right ventricle (RV) failure, which results from RV hypotrophy due to an overburdened hydraulic workload. The objective of this study is to correlate wall shear stress (WSS) with hemodynamic metrics that are generally accepted as clinical indicators of RV workload and are well correlated with disease outcome. Retrospective right heart catheterization data for 20 PH patients were analyzed to derive pulmonary vascular resistance (PVR), arterial compliance (C), and an index of wave reflections (Γ). Patient-specific contrast-enhanced computed tomography chest images were used to reconstruct the individual pulmonary arterial trees up to the seventh generation. Computational fluid dynamics analyses simulating blood flow at peak systole were conducted for each vascular model to calculate WSS distributions on the endothelial surface of the pulmonary arteries. WSS was found to be decreased proportionally with elevated PVR and reduced C. Spatially averaged WSS (SAWSS) was positively correlated with PVR (R (2) = 0.66), C (R (2) = 0.73), and Γ (R (2) = 0.5) and also showed promising preliminary correlations with RV geometric characteristics. Evaluating WSS at random cross sections in the proximal vasculature (main, right, and left pulmonary arteries), the type of data that can be acquired from phase-contrast magnetic resonance imaging, did not reveal the same correlations. In conclusion, we found that WSS has the potential to be a viable and clinically useful noninvasive metric of PH disease progression and RV health. Future work should be focused on evaluating whether SAWSS has prognostic value in the management of PH and whether it can be used as a rapid reactivity assessment tool, which would aid in selection of appropriate therapies.
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Affiliation(s)
- Vitaly Kheyfets
- Department of Biomedical Engineering, University of Texas, San Antonio, Texas, USA
| | | | - Lourdes Rios
- Department of Biological Sciences, University of Texas, San Antonio, Texas, USA
| | - Daniel Evans
- Department of Mechanical Engineering, University of Texas, San Antonio, Texas, USA
| | - Triston Smith
- Department of Cardiology, McGinnis Cardiovascular Institute, Allegheny General Hospital, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
| | - Theodore Schroeder
- Department of Radiology, McGinnis Cardiovascular Institute, Allegheny General Hospital, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
| | - Jeffrey Mueller
- Department of Radiology, McGinnis Cardiovascular Institute, Allegheny General Hospital, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
| | - Srinivas Murali
- Department of Cardiology, McGinnis Cardiovascular Institute, Allegheny General Hospital, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
| | - David Lasorda
- Department of Cardiology, McGinnis Cardiovascular Institute, Allegheny General Hospital, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
| | - Jennifer Spotti
- Department of Cardiology, McGinnis Cardiovascular Institute, Allegheny General Hospital, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
| | - Ender Finol
- Department of Biomedical Engineering, University of Texas, San Antonio, Texas, USA
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14
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Kheyfets VO, O'Dell W, Smith T, Reilly JJ, Finol EA. Considerations for numerical modeling of the pulmonary circulation--a review with a focus on pulmonary hypertension. J Biomech Eng 2013; 135:61011-15. [PMID: 23699723 PMCID: PMC3705788 DOI: 10.1115/1.4024141] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 03/25/2013] [Accepted: 04/04/2013] [Indexed: 12/12/2022]
Abstract
Both in academic research and in clinical settings, virtual simulation of the cardiovascular system can be used to rapidly assess complex multivariable interactions between blood vessels, blood flow, and the heart. Moreover, metrics that can only be predicted with computational simulations (e.g., mechanical wall stress, oscillatory shear index, etc.) can be used to assess disease progression, for presurgical planning, and for interventional outcomes. Because the pulmonary vasculature is susceptible to a wide range of pathologies that directly impact and are affected by the hemodynamics (e.g., pulmonary hypertension), the ability to develop numerical models of pulmonary blood flow can be invaluable to the clinical scientist. Pulmonary hypertension is a devastating disease that can directly benefit from computational hemodynamics when used for diagnosis and basic research. In the present work, we provide a clinical overview of pulmonary hypertension with a focus on the hemodynamics, current treatments, and their limitations. Even with a rich history in computational modeling of the human circulation, hemodynamics in the pulmonary vasculature remains largely unexplored. Thus, we review the tasks involved in developing a computational model of pulmonary blood flow, namely vasculature reconstruction, meshing, and boundary conditions. We also address how inconsistencies between models can result in drastically different flow solutions and suggest avenues for future research opportunities. In its current state, the interpretation of this modeling technology can be subjective in a research environment and impractical for clinical practice. Therefore, considerations must be taken into account to make modeling reliable and reproducible in a laboratory setting and amenable to the vascular clinic. Finally, we discuss relevant existing models and how they have been used to gain insight into cardiopulmonary physiology and pathology.
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Affiliation(s)
- V. O. Kheyfets
- Department of Biomedical Engineering,The University of Texas at San Antonio,AET 1.360, One UTSA Circle,San Antonio, TX 78249
| | - W. O'Dell
- Department of Radiation Oncology,University of Florida,Shands Cancer Center,P.O. Box 100385,2033 Mowry Road,Gainesville, FL 32610
| | - T. Smith
- Western Allegheny Health System,Allegheny General Hospital,Gerald McGinnis Cardiovascular Institute,320 East North Avenue,Pittsburgh, PA 15212
| | - J. J. Reilly
- Department of Medicine,The University of Pittsburgh,1218 Scaife Hall,3550 Terrace Street,Pittsburgh, PA 15261
| | - E. A. Finol
- Department of Biomedical Engineering,The University of Texas at San Antonio,AET 1.360, One UTSA Circle,San Antonio, TX 78249e-mail:
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Adatia I, Haworth SG, Wegner M, Barst RJ, Ivy D, Stenmark KR, Karkowsky A, Rosenzweig E, Aguilar C. Clinical trials in neonates and children: Report of the pulmonary hypertension academic research consortium pediatric advisory committee. Pulm Circ 2013; 3:252-66. [PMID: 23662203 PMCID: PMC3641736 DOI: 10.4103/2045-8932.109931] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Drug trials in neonates and children with pulmonary hypertensive vascular disease pose unique but not insurmountable challenges. Childhood is defined by growth and development. Both may influence disease and outcomes of drug trials. The developing pulmonary vascular bed and airways may be subjected to maldevelopment, maladaptation, growth arrest, or dysregulation that influence the disease phenotype. Drug therapy is influenced by developmental changes in renal and hepatic blood flow, as well as in metabolic systems such as cytochrome P450. Drugs may affect children differently from adults, with different clearance, therapeutic levels and toxicities. Toxicity may not be manifested until the child reaches physical, endocrine and neurodevelopmental maturity. Adverse effects may be revealed in the next generation, should the development of ova or spermatozoa be affected. Consideration of safe, age-appropriate tablets and liquid formulations is an obvious but often neglected prerequisite to any pediatric drug trial. In designing a clinical trial, precise phenotyping and genotyping of disease is required to ensure appropriate and accurate inclusion and exclusion criteria. We need to explore physiologically based pharmacokinetic modeling and simulations together with statistical techniques to reduce sample size requirements. Clinical endpoints such as exercise capacity, using traditional classifications and testing cannot be applied routinely to children. Many lack the necessary neurodevelopmental skills and equipment may not be appropriate for use in children. Selection of endpoints appropriate to encompass the developmental spectrum from neonate to adolescent is particularly challenging. One possible solution is the development of composite outcome scores that include age and a developmentally specific functional classification, growth and development scores, exercise data, biomarkers and hemodynamics with repeated evaluation throughout the period of growth and development. In addition, although potentially costly, we recommend long-term continuation of blinded dose ranging after completion of the short-term, double-blind, placebo-controlled trial for side-effect surveillance, which should include neurodevelopmental and peripubertal monitoring. The search for robust evidence to guide safe therapy of children and neonates with pulmonary hypertensive vascular disease is a crucial and necessary goal.
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Affiliation(s)
- Ian Adatia
- Stollery Children's Hospital, University of Alberta, Edmonton, Canada
| | | | | | | | - Dunbar Ivy
- Children's Hospital of Colorado, University of Colorado, Denver, Colorado, USA
| | - Kurt R. Stenmark
- Children's Hospital of Colorado, University of Colorado, Denver, Colorado, USA
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