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Siddiqui HB, Golcez T, Çelik M, Sevgin B, Çoban M, Süder İ, Kaya Ö, Özören N, Pekkan K. Modulation of mechanosensitive genes during embryonic aortic arch development. Dev Dyn 2024. [PMID: 39096177 DOI: 10.1002/dvdy.728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 05/30/2024] [Accepted: 07/17/2024] [Indexed: 08/05/2024] Open
Abstract
BACKGROUND Early embryonic aortic arches (AA) are a dynamic vascular structures that are in the process of shaping into the great arteries of cardiovascular system. Previously, a time-lapsed mechanosensitive gene expression map was established for AA subject to altered mechanical loads in the avian embryo. To validate this map, we investigated effects on vascular microstructure and material properties following the perturbation of key genes using an in-house microvascular gene knockdown system. RESULTS All siRNA vectors show a decrease in the expression intensity of desired genes with no significant differences between vectors. In TGFβ3 knockdowns, we found a reduction in expression intensities of TGFβ3 (≤76%) and its downstream targets such as ELN (≤99.6%), Fbn1 (≤60%), COL1 (≤52%) and COL3 (≤86%) and an increase of diameter in the left AA (23%). MMP2 knockdown also reduced expression levels in MMP2 (≤30%) and a 6-fold increase in its downstream target COL3 with a decrease in stiffness of the AA wall and an increase in the diameter of the AA (55%). These in vivo measurements were confirmed using immunohistochemistry, western blotting and a computational growth model of the vascular extracellular matrix (ECM). CONCLUSIONS Localized spatial genetic modification of the aortic arch region governs the vascular phenotype and ECM composition of the embryo and can be integrated with mechanically-induced congenital heart disease models.
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Affiliation(s)
| | - Tansu Golcez
- Biomedical Sciences and Engineering Program, Koç University, Istanbul, Turkey
- Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey
| | - Merve Çelik
- Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey
| | - Börteçine Sevgin
- Biomedical Sciences and Engineering Program, Koç University, Istanbul, Turkey
| | - Mervenur Çoban
- Biomedical Sciences and Engineering Program, Koç University, Istanbul, Turkey
| | - İlke Süder
- Department of Molecular Biology and Genetics, Bogazici University, Turkey
| | - Özen Kaya
- Department of Molecular Biology and Genetics, Bogazici University, Turkey
- Department of Mechanical Engineering, Koç University, Istanbul, Turkey
| | - Nesrin Özören
- Department of Molecular Biology and Genetics, Bogazici University, Turkey
| | - Kerem Pekkan
- Biomedical Sciences and Engineering Program, Koç University, Istanbul, Turkey
- Department of Mechanical Engineering, Koç University, Istanbul, Turkey
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Ramachandra AB, Cavinato C, Humphrey JD. A Systematic Comparison of Normal Structure and Function of the Greater Thoracic Vessels. Ann Biomed Eng 2024; 52:958-966. [PMID: 38227167 DOI: 10.1007/s10439-023-03432-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 12/23/2023] [Indexed: 01/17/2024]
Abstract
The greater thoracic vessels are central to a well-functioning circulatory system and are often targeted in congenital heart surgeries, yet the structure and function of these vessels have not been well studied. Here we use consistent methods to quantify and compare microstructural features and biaxial biomechanical properties of the following six greater thoracic vessels in wild-type mice: ascending thoracic aorta, descending thoracic aorta, right subclavian artery, right pulmonary artery, thoracic inferior vena cava, and superior vena cava. Specifically, we determine volume fractions and orientations of the structurally significant wall constituents (i.e., collagen, elastin, and cell nuclei) using multiphoton imaging, and we quantify vasoactive responses and mechanobiologically relevant mechanical quantities (e.g., stress, stiffness) using computer-controlled biaxial mechanical testing. Similarities and differences across systemic, pulmonary, and venous circulations highlight underlying design principles of the vascular system. Results from this study represent another step towards understanding growth and remodeling of greater thoracic vessels in health, disease, and surgical interventions by providing baseline information essential for developing and validating predictive computational models.
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Affiliation(s)
- Abhay B Ramachandra
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520, USA.
- Department of Mechanical Engineering, Iowa State University, Ames, IA, USA.
| | - Cristina Cavinato
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520, USA
- Laboratoire de Mécanique et Génie Civile, Université Montpellier, Montpellier, France
| | - Jay D Humphrey
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520, USA.
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA.
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Zhuravleva IY, Karpova EV, Dokuchaeva AA, Titov AT, Timchenko TP, Vasilieva MB. Calcification of Various Bioprosthetic Materials in Rats: Is It Really Different? Int J Mol Sci 2023; 24:ijms24087274. [PMID: 37108443 PMCID: PMC10139218 DOI: 10.3390/ijms24087274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/05/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
The causes of heart valve bioprosthetic calcification are still not clear. In this paper, we compared the calcification in the porcine aorta (Ao) and the bovine jugular vein (Ve) walls, as well as the bovine pericardium (Pe). Biomaterials were crosslinked with glutaraldehyde (GA) and diepoxide (DE), after which they were implanted subcutaneously in young rats for 10, 20, and 30 days. Collagen, elastin, and fibrillin were visualized in non-implanted samples. Atomic absorption spectroscopy, histological methods, scanning electron microscopy, and Fourier-transform infrared spectroscopy were used to study the dynamics of calcification. By the 30th day, calcium accumulated most intensively in the collagen fibers of the GA-Pe. In elastin-rich materials, calcium deposits were associated with elastin fibers and localized differences in the walls of Ao and Ve. The DE-Pe did not calcify at all for 30 days. Alkaline phosphatase does not affect calcification since it was not found in the implant tissue. Fibrillin surrounds elastin fibers in the Ao and Ve, but its involvement in calcification is questionable. In the subcutaneous space of young rats, which are used to model the implants' calcification, the content of phosphorus was five times higher than in aging animals. We hypothesize that the centers of calcium phosphate nucleation are the positively charged nitrogen of the pyridinium rings, which is the main one in fresh elastin and appears in collagen as a result of GA preservation. Nucleation can be significantly accelerated at high concentrations of phosphorus in biological fluids. The hypothesis needs further experimental confirmation.
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Affiliation(s)
- Irina Y Zhuravleva
- E. Meshalkin National Medical Research Center of the RF Ministry of Health, 15 Rechkunovskaya St., 630055 Novosibirsk, Russia
| | - Elena V Karpova
- N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, 9 Lavrentiev Avenue, 630090 Novosibirsk, Russia
| | - Anna A Dokuchaeva
- E. Meshalkin National Medical Research Center of the RF Ministry of Health, 15 Rechkunovskaya St., 630055 Novosibirsk, Russia
| | - Anatoly T Titov
- V. Sobolev Institute of Geology and Mineralogy SB RAS, 3 Academician Koptyug Avenue, 630090 Novosibirsk, Russia
| | - Tatiana P Timchenko
- E. Meshalkin National Medical Research Center of the RF Ministry of Health, 15 Rechkunovskaya St., 630055 Novosibirsk, Russia
| | - Maria B Vasilieva
- E. Meshalkin National Medical Research Center of the RF Ministry of Health, 15 Rechkunovskaya St., 630055 Novosibirsk, Russia
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External iliac vein dimensions may change after placement of a more proximal iliac vein stent. J Vasc Surg Venous Lymphat Disord 2022; 11:373-378. [PMID: 37195818 DOI: 10.1016/j.jvsv.2022.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 09/11/2022] [Accepted: 09/19/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVE We have occasionally observed during vein stenting for proximal iliac vein stenosis, the appearance of a more distal stenosis in the iliac vein that had not been initially observed before placement of the more proximal vein stent. In the present retrospective study, we aimed to document this observation. METHODS We identified patients in whom changes in the area measurement and linear dimensions of the external iliac vein (EIV) were observed on venography and/or intravascular ultrasound (IVUS) after stent placement for chronic nonthrombotic iliac stenosis in the common iliac vein (CIV). The images of these IVUS scans were subsequently analyzed to determine the cross-sectional area, major axis, and minor axis measurements in the EIV, before and after placement of a proximal CIV stent. RESULTS A total of 32 limbs with complete and quality IVUS and venography images available that allowed for measurement of the EIV before and after vein stent placement in the CIV were evaluated. The patient cohort was 55% men, with a mean age of 63.8 ± 9.9 years and a mean body mass index of 27.8 ± 7.8 kg/m2. Of the 32 limbs, 18 were left sided and 14 were right sided. Most (n = 12 [60%]) of the limbs had presented with venous-related skin changes (C4 disease). The remainder of the cohort had had active (C6 disease; n = 4 [20%]) or recently healed (C5 disease; n = 1 [5%]) venous ulceration and isolated venous-related edema (C3; n = 3 [15%]). The minimal CIV area before and after CIV stenting was 28.47 ± 23.53 mm2 and 196.34 ± 42.62 mm2, respectively. The minimal mean EIV cross-sectional area before and after CIV stenting was 87.44 ± 38.55 mm2 and 50.69 ± 24.32 mm2, respectively, a statistically significant reduction of 36.75 mm2 (P < .001). The mean EIV major axis and minor axis had both decreased similarly. The minimal mean EIV major axis before and after CIV stenting was 15.22 ± 3.13 mm and 11.13 ± 3.58 mm, respectively (P < .001). The minimal mean EIV minor axis before and after CIV stenting was 7.26 ± 2.40 mm and 5.84 ± 1.42 mm, respectively (P < .001). CONCLUSIONS The results from the present study have shown that the dimensions of the EIV can change significantly after placement of a proximal CIV stent. Possible explanations include masked stenosis due to distal venous distention resulting from the more proximal stenosis, vascular spasm, and anisotropy. The presence of proximal CIV stenosis can potentially lessen the appearance, or completely mask the presence, of an EIV stenosis. This phenomenon appears unique to venous stenting, and the prevalence is unknown. These findings underscore the importance of completion IVUS and venography after venous stent placement.
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He X, Auricchio F, Morganti S, Lu J. Uniaxial properties of ascending aortic aneurysms in light of effective stretch. Acta Biomater 2021; 136:306-313. [PMID: 34560300 DOI: 10.1016/j.actbio.2021.09.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/07/2021] [Accepted: 09/16/2021] [Indexed: 01/15/2023]
Abstract
A constitutive model that explicitly considers the gradual recruitment of collagen fibers is applied to investigate the uniaxial properties of human ascending aortic aneurysms. The model uses an effective stretch, which is a continuum scale kinematic variable measuring the true stretch of the tissue, to formulate the fiber stress. The constitutive equation contains two shape parameters characterizing the stochastic distribution of fiber waviness, and two elastic parameters accounting for, respectively, the elastic properties of ground substance and the straightened collagen fibers. The model is applied to 156 sets of uniaxial stress-stretch data obtained from 52 aneurysm samples. Major findings include (1) the uniaxial response can be well described by a quadratic strain energy function of the effective strain; (2) the ultimate stretches, when measured in terms of the effective stretch, are closely clustered around 1.1, in contrast to a much wider range in the original stretch; and (3) the ultimate stress correlates positively with the fiber stiffness. The age dependence and directional differences of constitutive parameters are also investigated. Results indicate that only the waviness depends strongly on age; no clear alterations occur in elastic parameters. Further, the fibers are wavier and stiffer in the circumferential direction than in the longitudinal direction. No other parameters exhibit significant direction difference. STATEMENT OF SIGNIFICANCE: We introduced a constitutive model which explicitly accounts for collagen fiber recruitment to investigate the uniaxial properties of human ascending aortic aneurysm tissues. Uniaxial response data from 156 specimens were considered in the study. It was found that the seemingly dissimilar response curves are, in fact, similar if we measure the deformation using an effective stretch which factors out the uncrimping deformation. The rupture stretches in terms of the effective stretch are closely packed around 1.1. And the stress-stretch curves collapse to a canonical curve after a transformation.
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Affiliation(s)
- Xuehuan He
- Department of Mechanical Engineering, The University of Iowa, Iowa City, IA 52242, USA
| | - Ferdinando Auricchio
- Department of Civil Engineering and Architecture, University of Pavia, Pavia 27100, Italy
| | - Simone Morganti
- Department of Electrical, Computer, and Biomedical Engineering, University of Pavia, Pavia 27100, Italy
| | - Jia Lu
- Department of Mechanical Engineering, The University of Iowa, Iowa City, IA 52242, USA.
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Development of an FEA framework for analysis of subject-specific aortic compliance based on 4D flow MRI. Acta Biomater 2021; 125:154-171. [PMID: 33639309 DOI: 10.1016/j.actbio.2021.02.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/15/2021] [Accepted: 02/18/2021] [Indexed: 12/30/2022]
Abstract
This paper presents a subject-specific in-silico framework in which we uncover the relationship between the spatially varying constituents of the aorta and the non-linear compliance of the vessel during the cardiac cycle uncovered through our MRI investigations. A microstructurally motivated constitutive model is developed, and simulations reveal that internal vessel contractility, due to pre-stretched elastin and actively generated smooth muscle cell stress, must be incorporated, along with collagen strain stiffening, in order to accurately predict the non-linear pressure-area relationship observed in-vivo. Modelling of elastin and smooth muscle cell contractility allows for the identification of the reference vessel configuration at zero-lumen pressure, in addition to accurately predicting high- and low-compliance regimes under a physiological range of pressures. This modelling approach is also shown to capture the key features of elastin digestion and SMC activation experiments. The volume fractions of the constituent components of the aortic material model were computed so that the in-silico pressure-area curves accurately predict the corresponding MRI data at each location. Simulations reveal that collagen and smooth muscle volume fractions increase distally, while elastin volume fraction decreases distally, consistent with reported histological data. Furthermore, the strain at which collagen transitions from low to high stiffness is lower in the abdominal aorta, again supporting the histological finding that collagen waviness is lower distally. The analyses presented in this paper provide new insights into the heterogeneous structure-function relationship that underlies aortic biomechanics. Furthermore, this subject-specific MRI/FEA methodology provides a foundation for personalised in-silico clinical analysis and tailored aortic device development. STATEMENT OF SIGNIFICANCE: This study provides a significant advance in in-silico medicine by capturing the structure/function relationship of the subject-specific human aorta presented in our previous MRI analyses. A physiologically based aortic constitutive model is developed, and simulations reveal that internal vessel contractility must be incorporated, along with collagen strain stiffening, to accurately predict the in-vivo non-linear pressure-area relationship. Furthermore, this is the first subject-specific model to predict spatial variation in the volume fractions of aortic wall constituents. Previous studies perform phenomenological hyperelastic curve fits to medical imaging data and ignore the prestress contribution of elastin, collagen, and SMCs and the associated zero-pressure reference state of the vessel. This novel MRI/FEA framework can be used as an in-silico diagnostic tool for the early stage detection of aortic pathologies.
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7
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Wheen P, Mahon C, Sharma R, Rubens M, Nicol E. Inferior vena cava aneurysm in a patient with Ehlers-Danlos syndrome. J Cardiovasc Comput Tomogr 2021; 15:e94-e95. [PMID: 33745857 DOI: 10.1016/j.jcct.2021.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/04/2021] [Accepted: 03/06/2021] [Indexed: 10/21/2022]
Affiliation(s)
- Peter Wheen
- Royal Brompton and Harefield NHS Foundation Trust, UK.
| | - Ciara Mahon
- Royal Brompton and Harefield NHS Foundation Trust, UK
| | - Rakesh Sharma
- Royal Brompton and Harefield NHS Foundation Trust, UK
| | | | - Edward Nicol
- Royal Brompton and Harefield NHS Foundation Trust, UK; National Heart and Lung Institute, Imperial College London, UK
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Heusinkveld MHG, Holtackers RJ, Adriaans BP, Op't Roodt J, Arts T, Delhaas T, Reesink KD, Huberts W. Complementing sparse vascular imaging data by physiological adaptation rules. J Appl Physiol (1985) 2021; 130:571-588. [PMID: 33119465 DOI: 10.1152/japplphysiol.00250.2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mathematical modeling of pressure and flow waveforms in blood vessels using pulse wave propagation (PWP) models has tremendous potential to support clinical decision making. For a personalized model outcome, measurements of all modeled vessel radii and wall thicknesses are required. In clinical practice, however, data sets are often incomplete. To overcome this problem, we hypothesized that the adaptive capacity of vessels in response to mechanical load could be utilized to fill in the gaps of incomplete patient-specific data sets. We implemented homeostatic feedback loops in a validated PWP model to allow adaptation of vessel geometry to maintain physiological values of wall stress and wall shear stress. To evaluate our approach, we gathered vascular MRI and ultrasound data sets of wall thicknesses and radii of central and arm arterial segments of 10 healthy subjects. Reference models (i.e., termed RefModel, n = 10) were simulated using complete data, whereas adapted models (AdaptModel, n = 10) used data of one carotid artery segment only, and the remaining geometries in this model were estimated using adaptation. We evaluated agreement between RefModel and AdaptModel geometries, as well as that between pressure and flow waveforms of both models. Limits of agreement (bias ± 2 SD of difference) between AdaptModel and RefModel radii and wall thicknesses were 0.2 ± 2.6 mm and -140 ± 557 µm, respectively. Pressure and flow waveform characteristics of the AdaptModel better resembled those of the RefModels as compared with the model in which the vessels were not adapted. Our adaptation-based PWP model enables personalization of vascular geometries even when not all required data are available.NEW & NOTEWORTHY To benefit personalized pulse wave propagation (PWP) modeling, we propose a novel method that, instead of relying on extensive data sets on vascular geometries, incorporates physiological adaptation rules. The developed vascular adaptation model adequately predicted arterial radius and wall thickness compared with ultrasound and MRI estimates, obtained in humans. Our approach could be used as a tool to facilitate personalized modeling, notably in case of missing data, as routinely found in clinical settings.
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Affiliation(s)
| | - Robert J Holtackers
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Bouke P Adriaans
- Department of Cardiology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Jos Op't Roodt
- Department of Internal Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Theo Arts
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands
| | - Tammo Delhaas
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands
| | - Koen D Reesink
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands
| | - Wouter Huberts
- Department of Biomedical Engineering, Maastricht University, Maastricht, The Netherlands.,Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
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Schaafs LA, Tzschätzsch H, Figiel C, van der Giet M, Reshetnik A, Hamm B, Sack I, Elgeti T. Quantitative Time-Harmonic Ultrasound Elastography of the Abdominal Aorta and Inferior Vena Cava. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:2349-2355. [PMID: 31201021 DOI: 10.1016/j.ultrasmedbio.2019.05.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 02/18/2019] [Accepted: 05/20/2019] [Indexed: 06/09/2023]
Abstract
The purpose of this study was to evaluate the sensitivity of quantitative time-harmonic ultrasound elastography (THE) of the inferior vena cava (IVC) and abdominal aorta (AA) to changes in central volume status. THE of the IVC and AA was performed in 20 healthy volunteers before and after oral intake of 1 L of water and before or during passive leg raising to augment venous filling. Compound maps of shear wave speed (SWS) as surrogate measures of vessel wall stiffness were generated within the full field of view from multifrequency harmonic wave fields. SWS was measured in regions of the IVC and AA. Blood pressure, stroke volume, cardiac output and pulse wave velocity were recorded. Statistical significance of SWS changes was tested using one-way repeated-measures analysis of variance. SWS measured in the IVC increased from 1.71 ± 0.1 m/s before water intake to 1.82 ± 0.1 m/s during passive leg raising and, further, to 1.87 ± 0.1 m/s after hydration and to 1.95 ± 0.1 m/s with hydration plus passive leg raising (p < 0.001). SWS in the AA did not change significantly after hydration (2.14 ± 0.13 m/s vs. 2.15 ± 0.16 m/s; p = 0.792). SWS was significantly higher in the AA than in the IVC across all experiments (p < 0.001). Water drinking did not significantly influence blood pressure, pulse wave velocity and cardiac output (all p values >0.1), whereas stroke volume increased significantly (p = 0.031). Time-harmonic ultrasound elastography enables quantification of the wall stiffness of the large abdominal vessels and is sensitive to different volume and pressure states in the IVC.
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Affiliation(s)
- Lars-Arne Schaafs
- Department of Radiology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin and Campus Mitte, Berlin, Germany.
| | - Heiko Tzschätzsch
- Department of Radiology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin and Campus Mitte, Berlin, Germany
| | - Christin Figiel
- Department of Radiology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin and Campus Mitte, Berlin, Germany
| | - Markus van der Giet
- Department of Nephrology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Alexander Reshetnik
- Department of Nephrology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Bernd Hamm
- Department of Radiology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin and Campus Mitte, Berlin, Germany
| | - Ingolf Sack
- Department of Radiology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin and Campus Mitte, Berlin, Germany
| | - Thomas Elgeti
- Department of Radiology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin and Campus Mitte, Berlin, Germany; Department of Nuclear Medicine, Charité-Universitätsmedizin Berlin, Campus Virchow Klinikum, Berlin, Germany
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Crouch AC, Cao AA, Scheven UM, Greve JM. In Vivo MRI Assessment of Blood Flow in Arteries and Veins from Head-to-Toe Across Age and Sex in C57BL/6 Mice. Ann Biomed Eng 2019; 48:329-341. [PMID: 31456089 DOI: 10.1007/s10439-019-02350-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 08/20/2019] [Indexed: 10/26/2022]
Abstract
Although widely used as a preclinical model for studying cardiovascular diseases, there is a scarcity of in vivo hemodynamic measurements of the naïve murine system in multiple arterial and venous locations, from head-to-toe, and across sex and age. The purpose of this study is to quantify cardiovascular hemodynamics in mice at different locations along the vascular tree while evaluating the effects of sex and age. Male and female, adult and aged mice were anesthetized and underwent magnetic resonance imaging. Data were acquired from four co-localized vessel pairs (carotid/jugular, suprarenal and infrarenal aorta/inferior vena cava (IVC), femoral artery/vein) at normothermia (core temperature 37 ± 0.2 °C). Influences of age and sex on average velocity differ by location in arteries. Average arterial velocities, when plotted as a function of distance from the heart, decrease nearly linearly from the suprarenal aorta to the femoral artery (adult and aged males: - 0.33 ± 0.13, R2 = 0.87; - 0.43 ± 0.10, R2 = 0.95; adult and aged females: - 0.23 ± 0.07, R2 = 0.91; - 0.23 ± 0.02, R2 = 0.99). Average velocity of aged males and average volumetric flow of aged males and females tended to be larger compared to adult comparators. With cardiovascular disease as the leading cause of death and with the implications of cardiovascular hemodynamics as important biomarkers for health and disease, this work provides a foundation for sex and age comparisons in pathophysiology by collecting and analyzing hemodynamic data for the healthy murine arterial and venous system from head-to-toe, across sex and age.
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Affiliation(s)
- A Colleen Crouch
- Mechanical Engineering, University of Michigan, 1049 Bonisteel Interdisciplinary Research Building, 2360 Bonisteel Boulevard, Ann Arbor, MI, 48109-2099, USA.
| | - Amos A Cao
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Ulrich M Scheven
- Mechanical Engineering, University of Michigan, 1049 Bonisteel Interdisciplinary Research Building, 2360 Bonisteel Boulevard, Ann Arbor, MI, 48109-2099, USA
| | - Joan M Greve
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
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11
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Crouch AC, Scheven UM, Greve JM. Cross-sectional areas of deep/core veins are smaller at lower core body temperatures. Physiol Rep 2018; 6:e13839. [PMID: 30155984 PMCID: PMC6113131 DOI: 10.14814/phy2.13839] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 07/19/2018] [Accepted: 07/22/2018] [Indexed: 01/11/2023] Open
Abstract
The cardiovascular system plays a crucial role in thermoregulation. Deep core veins, due to their large size and role in returning blood to the heart, are an important part of this system. The response of veins to increasing core temperature has not been adequately studied in vivo. Our objective was to noninvasively quantify in C57BL/6 mice the response of artery-vein pairs to increases in body temperature. Adult male mice were anesthetized and underwent magnetic resonance imaging. Data were acquired from three colocalized vessel pairs (the neck [carotid/jugular], torso [aorta/inferior vena cava (IVC)], periphery [femoral artery/vein]) at core temperatures of 35, 36, 37, and 38°C. Cross-sectional area increased with increasing temperature for all vessels, excluding the carotid. Average area of the jugular, aorta, femoral artery, and vein linearly increased with temperature (0.10, 0.017, 0.017, and 0.027 mm2 /°C, respectively; P < 0.05). On average, the IVC has the largest venous response for area (18.2%/°C, vs. jugular 9.0 and femoral 10.9%/°C). Increases in core temperature from 35 to 38 °C resulted in an increase in contact length between the aorta/IVC of 29.3% (P = 0.007) and between the femoral artery/vein of 28.0% (P = 0.03). Previously unidentified increases in the IVC area due to increasing core temperature are biologically important because they may affect conductive and convective heat transfer. Vascular response to temperature varied based on location and vessel type. Leveraging noninvasive methodology to quantify vascular responses to temperature could be combined with bioheat modeling to improve understanding of thermoregulation.
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Affiliation(s)
| | - Ulrich M. Scheven
- Department of Biomedical EngineeringUniversity of MichiganAnn ArborMichigan
| | - Joan M. Greve
- Department of Biomedical EngineeringUniversity of MichiganAnn ArborMichigan
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