The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Amir Lerman - One of the best experts on this subject based on the ideXlab platform.
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IVUS detection of Vasa Vasorum blood flow distribution in coronary artery vessel wall.
JACC. Cardiovascular imaging, 2012Co-Authors: Regina Moritz, Amir Lerman, Diane R. Eaker, Jill L. Anderson, Timothy L. Kline, Steven M. Jorgensen, Erik L. RitmanAbstract:There is an increased body of evidence to suggest that the Vasa Vasorum play a major role in the progression and complications of vulnerable plaque leading to acute coronary syndrome. We propose that detecting changes in the flow in the vascular wall by intravascular ultrasound signals can quantify the presence of Vasa Vasorum. The results obtained in a porcine model of atherosclerosis suggest that intravascular ultrasound-based estimates of blood flow in the arterial wall can be used in vivo in a clinical research setting to establish the density of Vasa Vasorum as an indicator of plaque vulnerability.
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The Dynamic Vasa Vasorum
Cardiovascular research, 2007Co-Authors: Erik L. Ritman, Amir LermanAbstract:The function of Vasa Vasorum is both to deliver nutrients and oxygen to arterial and venous walls and to remove "waste" products, either produced by cells in the wall or introduced by diffusional transport through the endothelium of the artery or vein. Although the relationship between changes in Vasa Vasorum characteristics and the development of atheromatous plaques is well documented, the role of Vasa Vasorum, especially in terms of their appearance and disappearance in disease processes such as atherosclerosis, are still not clearly understood in terms of their being causative or merely reactive. However, even if their proliferation is merely reactive, these new microvessels may be a source of disease progression by virtue of endothelial impairment and as a pathway for monocytic cells to migrate to sites of early disease. As both these features are aspects of the Vasa Vasorum function, this Review focuses on the following issues: 1) acute modulation of Vasa Vasorum patency due to surrounding compressive forces within vessel wall and due to variable tone in the smooth muscle within proximal Vasa Vasorum and 2) chronic angiogenic responses due to local cytokine accumulations such as occur in the wall of arteries in the presence of hypertension, hypercholesterolemia, accumulation of lipids, extraVasated blood products (e.g., red blood cells, macrophages, inflammatory products) which attract monocytes, and response of Vasa Vasorum to pharmacological stimuli.
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experimental hypercholesterolemia differentially affects adventitial Vasa Vasorum and vessel structure of the left internal thoracic and coronary arteries
The Journal of Thoracic and Cardiovascular Surgery, 2005Co-Authors: Offer Galili, Joerg Herrmann, Lilach O Lerman, Katherine J. Sattler, Julie Woodrum, Monica Olson, Amir LermanAbstract:Objective Atherosclerosis is a chronic and diffuse disease that affects all vascular beds. However, some vascular beds are more prone to atherosclerosis than others. Recent evidence suggests a role for the Vasa Vasorum in the atherosclerotic process. We hypothesized that there is a difference in adventitial Vasa Vasorum structure between the left internal thoracic artery and the coronary artery. Hence the current study was designed to characterize and compare the structure of the adventitial Vasa Vasorum in the left internal thoracic and coronary arteries. Methods Samples of vessels were obtained from female crossbred domestic pigs maintained on a normal (n = 6) or high-cholesterol (n = 6) diet for 12 weeks. The samples were scanned with micro-computed tomography, and the tomographic images were reconstructed and analyzed to obtain lumen area, vessel wall area, Vasa Vasorum count, Vasa Vasorum density, mean diameter of first- and second-order Vasa Vasorum, and second-order/first-order Vasa Vasorum ratio. Results Vasa Vasorum density was significantly higher in the coronary arteries versus that seen in the left internal thoracic arteries in the normal group, as well as in the high-cholesterol group. The higher Vasa Vasorum density in the high-cholesterol group versus that in the normal group was significant for both vessels, being more pronounced in the left internal thoracic artery. Lumen area and second-order/first-order Vasa Vasorum ratio were higher in the high-cholesterol group than in the normal group only in the left internal thoracic artery. Conclusion This study demonstrated that low Vasa Vasorum spatial density and higher lumen area observed in the left internal thoracic artery compared with that seen in the native coronary artery can be the structural background for the low incidence of atherosclerosis in this vessel.
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Experimental hypercholesterolemia differentially affects adventitial Vasa Vasorum and vessel structure of the left internal thoracic and coronary arteries.
The Journal of thoracic and cardiovascular surgery, 2005Co-Authors: Offer Galili, Joerg Herrmann, Lilach O Lerman, Katherine J. Sattler, Julie Woodrum, Monica Olson, Amir LermanAbstract:Atherosclerosis is a chronic and diffuse disease that affects all vascular beds. However, some vascular beds are more prone to atherosclerosis than others. Recent evidence suggests a role for the Vasa Vasorum in the atherosclerotic process. We hypothesized that there is a difference in adventitial Vasa Vasorum structure between the left internal thoracic artery and the coronary artery. Hence the current study was designed to characterize and compare the structure of the adventitial Vasa Vasorum in the left internal thoracic and coronary arteries. Samples of vessels were obtained from female crossbred domestic pigs maintained on a normal (n = 6) or high-cholesterol (n = 6) diet for 12 weeks. The samples were scanned with micro-computed tomography, and the tomographic images were reconstructed and analyzed to obtain lumen area, vessel wall area, Vasa Vasorum count, Vasa Vasorum density, mean diameter of first- and second-order Vasa Vasorum, and second-order/first-order Vasa Vasorum ratio. Vasa Vasorum density was significantly higher in the coronary arteries versus that seen in the left internal thoracic arteries in the normal group, as well as in the high-cholesterol group. The higher Vasa Vasorum density in the high-cholesterol group versus that in the normal group was significant for both vessels, being more pronounced in the left internal thoracic artery. Lumen area and second-order/first-order Vasa Vasorum ratio were higher in the high-cholesterol group than in the normal group only in the left internal thoracic artery. This study demonstrated that low Vasa Vasorum spatial density and higher lumen area observed in the left internal thoracic artery compared with that seen in the native coronary artery can be the structural background for the low incidence of atherosclerosis in this vessel.
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Chronic endothelin receptor antagonism prevents coronary Vasa Vasorum neovascularization in experimental hypercholesterolemia
Journal of the American College of Cardiology, 2002Co-Authors: Joerg Herrmann, David R. Holmes, Erik L. Ritman, Lilach O Lerman, Patricia J.m. Best, Amir LermanAbstract:The purpose of this study was to test the hypothesis that endothelin (ET) receptor antagonism reduces coronary Vasa Vasorum neovascularization in experimental hypercholesterolemia. Experimental hypercholesterolemia is associated with increased expression of ET-1, an endothelium-derived peptide with vasoconstricting, mitogenic and angiogenic properties, in the coronary arterial wall as well as with Vasa Vasorum neovascularization. A pathomechanistic role of the endogenous ET system in Vasa Vasorum neovascularization in hypercholesterolemia has, however, remained uncertain so far. Female domestic pigs were placed on a normal diet (N; n = 7) or on a hypercholesterolemic diet without (HC; n = 6) or with ET-A receptor antagonism (ABT-627, 4 mg/kg/day; HC + ET-A; n = 6). After 12 weeks, coronary Vasa Vasorum structure was assessed by three-dimensional microscopic computed tomography, expression of vascular endothelial growth factor (VEGF) within the coronary arterial wall by Western blotting and immunostaining. Compared with the N group, plasma concentrations of low-density lipoprotein cholesterol were higher in both the HC and HC + ET-A groups (36 +/- 3 mg/dl vs. 312 +/- 153 mg/dl and 303 +/- 113 mg/dl, p < 0.01). Vasa Vasorum density was higher in the HC group compared with the N group (4.7 +/- 1.8 per mm(2) vs. 2.5 +/- 1.5 per mm(2); p < 0.05) and was preserved in the HC + ET-A group (3.2 +/- 0.7 per mm(2)). In parallel, increase in VEGF expression in the coronary arterial wall in the HC group was preserved in the HC + ET-A group. The current study demonstrates that chronic endothelin receptor antagonism prevents the increase in VEGF expression and Vasa Vasorum density of coronary arteries in experimental hypercholesterolemia. These findings support a role for the endogenous ET system in Vasa Vasorum neovascularization in early coronary atherosclerosis.
Erik L. Ritman - One of the best experts on this subject based on the ideXlab platform.
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IVUS detection of Vasa Vasorum blood flow distribution in coronary artery vessel wall.
JACC. Cardiovascular imaging, 2012Co-Authors: Regina Moritz, Amir Lerman, Diane R. Eaker, Jill L. Anderson, Timothy L. Kline, Steven M. Jorgensen, Erik L. RitmanAbstract:There is an increased body of evidence to suggest that the Vasa Vasorum play a major role in the progression and complications of vulnerable plaque leading to acute coronary syndrome. We propose that detecting changes in the flow in the vascular wall by intravascular ultrasound signals can quantify the presence of Vasa Vasorum. The results obtained in a porcine model of atherosclerosis suggest that intravascular ultrasound-based estimates of blood flow in the arterial wall can be used in vivo in a clinical research setting to establish the density of Vasa Vasorum as an indicator of plaque vulnerability.
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The Dynamic Vasa Vasorum
Cardiovascular research, 2007Co-Authors: Erik L. Ritman, Amir LermanAbstract:The function of Vasa Vasorum is both to deliver nutrients and oxygen to arterial and venous walls and to remove "waste" products, either produced by cells in the wall or introduced by diffusional transport through the endothelium of the artery or vein. Although the relationship between changes in Vasa Vasorum characteristics and the development of atheromatous plaques is well documented, the role of Vasa Vasorum, especially in terms of their appearance and disappearance in disease processes such as atherosclerosis, are still not clearly understood in terms of their being causative or merely reactive. However, even if their proliferation is merely reactive, these new microvessels may be a source of disease progression by virtue of endothelial impairment and as a pathway for monocytic cells to migrate to sites of early disease. As both these features are aspects of the Vasa Vasorum function, this Review focuses on the following issues: 1) acute modulation of Vasa Vasorum patency due to surrounding compressive forces within vessel wall and due to variable tone in the smooth muscle within proximal Vasa Vasorum and 2) chronic angiogenic responses due to local cytokine accumulations such as occur in the wall of arteries in the presence of hypertension, hypercholesterolemia, accumulation of lipids, extraVasated blood products (e.g., red blood cells, macrophages, inflammatory products) which attract monocytes, and response of Vasa Vasorum to pharmacological stimuli.
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Vasa Vasorum growth in the coronary arteries of newborn pigs
Anatomy and embryology, 2004Co-Authors: Mario Gössl, Mair Zamir, Erik L. RitmanAbstract:Experimental studies have shown that a "plexus" of Vasa Vasorum already exists in fetal arteries. In this study we examine the further development of Vasa Vasorum in the newborn. Hearts from 1- and 6-month-old pigs were harvested and infused with Microfil via the aortic ostia of the coronary arteries at physiological pressure (100 mmHg). Coronary arteries (RCA, LAD, and LCX) were then isolated and scanned intact with micro-CT (20 microm cubic voxel size). Using Analyze 5.0 software we digitally isolated individual Vasa Vasorum trees (eight from 1-month-old and eight from 6-month-old pigs) and measured geometrical data such as interbranch segmental diameters, lengths, and branching angles as well as mother-daughter branch relationships for all segments of each Vasa Vasorum tree structure. Also, we determined the volume of vessel wall perfused by individual Vasa Vasorum trees. Our results show that the Vasa Vasorum architecture in newborn pigs is already tree-like, and this structure as well as the volume of vessel wall perfused by it expand in concert with the growth of the host coronary artery. We give quantitative details of this growth of Vasa Vasorum in terms of its branching architecture and hemodynamic capacity, based on direct measurements from 3D images of this microvasculature.
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Impact of coronary Vasa Vasorum functional structure on coronary vessel wall perfusion distribution
American journal of physiology. Heart and circulatory physiology, 2003Co-Authors: Mario Gössl, Nasser M. Malyar, Michael Rosol, Patricia E. Beighley, Erik L. RitmanAbstract:Noncoronary Vasa Vasorum have been described as networks of microvessels in the wall of arteries and veins. However, we have shown, using microcomputerized tomography (micro-CT) imaging methods, that porcine coronary Vasa Vasorum have a tree-like branching structure similar to the vasculature in general. In this study, we elucidate functional aspects of coronary Vasa Vasorum perfusion territories. Three pig hearts were injected with radiopaque Microfil via the coronary sinus to fill the left anterior descending coronary arteries (LADs) retrogradely at atmospheric pressure. In three other hearts, LADs were injected antegradely at 100-mmHg pressure via the left main carotid artery. Additionally, six LADs were injected in vivo with a suspension of 100- or 300-microm-diameter microspheres before harvesting of the hearts and injection of the LADs with Microfil. All harvested LADs were scanned intact with micro-CT (20 microm cubic voxels). The spatial density of Vasa Vasorum (no. of Vasa/mm2) was measured in 20-microm-thick cross sections (at 0.4-mm intervals). Retrogradely injected LADs showed high and uniformly distributed Vasa Vasorum densities in the adventitia (means +/- SE; 5.38 +/- 0.09 vs. 3.58 +/- 0.1 Vasa/mm2 in antegradely prepared LADs; P < 0.001). Antegradely prepared LADs showed patchy distributed, low-Vasa-Vasorum-density territories especially on the myocardial side of the coronary artery wall (epicardial density: 4.29 +/- 0.13 Vasa/mm2 vs. myocardial density: 2.80 +/- 0.1 Vasa/mm2, P < 0.001). Microembolization reduced Vasa Vasorum densities significantly (100-mum-diameter microspheres: 3.26 +/- 0.07 Vasa/mm2, P < 0.05; 300-microm-diameter microspheres: 2.66 +/- 0.07 Vasa/mm2, P < 0.001 vs. antegrade controls) and increased the size of low-Vasa-Vasorum-density territories. We conclude that coronary Vasa Vasorum are functional endarteries not connected via a plexus. This characteristic may have a significant impact on the spatial distribution of perfusion and drainage of the coronary vessel wall.
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Functional Anatomy and Hemodynamic Characteristics of Vasa Vasorum in the Walls of Porcine Coronary Arteries
The anatomical record. Part A Discoveries in molecular cellular and evolutionary biology, 2003Co-Authors: Mario Gössl, Mair Zamir, Nasser M. Malyar, Michael Rosol, Patricia E. Beighley, Lorraine A. Fitzpatrick, Erik L. RitmanAbstract:In this study Vasa Vasorum in the walls of porcine coronary arteries were examined, using three-dimensional (3D) micro-CT scanning techniques. These techniques leave the 3D structure of the Vasa Vasorum tree intact and thus provide a much more direct view of this structure than is possible from conventional histological sections. The study demonstrates-for the first time, we believe-both the different types and the fine architecture of these Vasa Vasorum. Furthermore, with the use of automated tree analysis software, it was possible to obtain quantitative geometrical data on the 3D structure of Vasa Vasorum trees that have not previously been available. The results indicate that despite the restrictive topology of the space in which they are present, the branching architecture of the Vasa Vasorum trees, which we surveyed, is surprisingly similar to that of vasculature in general. The volume of vessel wall tissue perfused or drained by a Vasa Vasorum tree was found to correlate well with the cross-sectional area of the root segment of the Vasa Vasorum tree, and the luminal surface area corresponding to this volume was found to be comparable with the surface area of an early atherosclerotic lesion. This is consistent with earlier findings that the ligation or removal of Vasa Vasorum leads to atherogenesis.
Joerg Herrmann - One of the best experts on this subject based on the ideXlab platform.
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experimental hypercholesterolemia differentially affects adventitial Vasa Vasorum and vessel structure of the left internal thoracic and coronary arteries
The Journal of Thoracic and Cardiovascular Surgery, 2005Co-Authors: Offer Galili, Joerg Herrmann, Lilach O Lerman, Katherine J. Sattler, Julie Woodrum, Monica Olson, Amir LermanAbstract:Objective Atherosclerosis is a chronic and diffuse disease that affects all vascular beds. However, some vascular beds are more prone to atherosclerosis than others. Recent evidence suggests a role for the Vasa Vasorum in the atherosclerotic process. We hypothesized that there is a difference in adventitial Vasa Vasorum structure between the left internal thoracic artery and the coronary artery. Hence the current study was designed to characterize and compare the structure of the adventitial Vasa Vasorum in the left internal thoracic and coronary arteries. Methods Samples of vessels were obtained from female crossbred domestic pigs maintained on a normal (n = 6) or high-cholesterol (n = 6) diet for 12 weeks. The samples were scanned with micro-computed tomography, and the tomographic images were reconstructed and analyzed to obtain lumen area, vessel wall area, Vasa Vasorum count, Vasa Vasorum density, mean diameter of first- and second-order Vasa Vasorum, and second-order/first-order Vasa Vasorum ratio. Results Vasa Vasorum density was significantly higher in the coronary arteries versus that seen in the left internal thoracic arteries in the normal group, as well as in the high-cholesterol group. The higher Vasa Vasorum density in the high-cholesterol group versus that in the normal group was significant for both vessels, being more pronounced in the left internal thoracic artery. Lumen area and second-order/first-order Vasa Vasorum ratio were higher in the high-cholesterol group than in the normal group only in the left internal thoracic artery. Conclusion This study demonstrated that low Vasa Vasorum spatial density and higher lumen area observed in the left internal thoracic artery compared with that seen in the native coronary artery can be the structural background for the low incidence of atherosclerosis in this vessel.
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Experimental hypercholesterolemia differentially affects adventitial Vasa Vasorum and vessel structure of the left internal thoracic and coronary arteries.
The Journal of thoracic and cardiovascular surgery, 2005Co-Authors: Offer Galili, Joerg Herrmann, Lilach O Lerman, Katherine J. Sattler, Julie Woodrum, Monica Olson, Amir LermanAbstract:Atherosclerosis is a chronic and diffuse disease that affects all vascular beds. However, some vascular beds are more prone to atherosclerosis than others. Recent evidence suggests a role for the Vasa Vasorum in the atherosclerotic process. We hypothesized that there is a difference in adventitial Vasa Vasorum structure between the left internal thoracic artery and the coronary artery. Hence the current study was designed to characterize and compare the structure of the adventitial Vasa Vasorum in the left internal thoracic and coronary arteries. Samples of vessels were obtained from female crossbred domestic pigs maintained on a normal (n = 6) or high-cholesterol (n = 6) diet for 12 weeks. The samples were scanned with micro-computed tomography, and the tomographic images were reconstructed and analyzed to obtain lumen area, vessel wall area, Vasa Vasorum count, Vasa Vasorum density, mean diameter of first- and second-order Vasa Vasorum, and second-order/first-order Vasa Vasorum ratio. Vasa Vasorum density was significantly higher in the coronary arteries versus that seen in the left internal thoracic arteries in the normal group, as well as in the high-cholesterol group. The higher Vasa Vasorum density in the high-cholesterol group versus that in the normal group was significant for both vessels, being more pronounced in the left internal thoracic artery. Lumen area and second-order/first-order Vasa Vasorum ratio were higher in the high-cholesterol group than in the normal group only in the left internal thoracic artery. This study demonstrated that low Vasa Vasorum spatial density and higher lumen area observed in the left internal thoracic artery compared with that seen in the native coronary artery can be the structural background for the low incidence of atherosclerosis in this vessel.
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Chronic endothelin receptor antagonism prevents coronary Vasa Vasorum neovascularization in experimental hypercholesterolemia
Journal of the American College of Cardiology, 2002Co-Authors: Joerg Herrmann, David R. Holmes, Erik L. Ritman, Lilach O Lerman, Patricia J.m. Best, Amir LermanAbstract:The purpose of this study was to test the hypothesis that endothelin (ET) receptor antagonism reduces coronary Vasa Vasorum neovascularization in experimental hypercholesterolemia. Experimental hypercholesterolemia is associated with increased expression of ET-1, an endothelium-derived peptide with vasoconstricting, mitogenic and angiogenic properties, in the coronary arterial wall as well as with Vasa Vasorum neovascularization. A pathomechanistic role of the endogenous ET system in Vasa Vasorum neovascularization in hypercholesterolemia has, however, remained uncertain so far. Female domestic pigs were placed on a normal diet (N; n = 7) or on a hypercholesterolemic diet without (HC; n = 6) or with ET-A receptor antagonism (ABT-627, 4 mg/kg/day; HC + ET-A; n = 6). After 12 weeks, coronary Vasa Vasorum structure was assessed by three-dimensional microscopic computed tomography, expression of vascular endothelial growth factor (VEGF) within the coronary arterial wall by Western blotting and immunostaining. Compared with the N group, plasma concentrations of low-density lipoprotein cholesterol were higher in both the HC and HC + ET-A groups (36 +/- 3 mg/dl vs. 312 +/- 153 mg/dl and 303 +/- 113 mg/dl, p < 0.01). Vasa Vasorum density was higher in the HC group compared with the N group (4.7 +/- 1.8 per mm(2) vs. 2.5 +/- 1.5 per mm(2); p < 0.05) and was preserved in the HC + ET-A group (3.2 +/- 0.7 per mm(2)). In parallel, increase in VEGF expression in the coronary arterial wall in the HC group was preserved in the HC + ET-A group. The current study demonstrates that chronic endothelin receptor antagonism prevents the increase in VEGF expression and Vasa Vasorum density of coronary arteries in experimental hypercholesterolemia. These findings support a role for the endogenous ET system in Vasa Vasorum neovascularization in early coronary atherosclerosis.
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chronic endothelin receptor antagonism prevents coronary Vasa Vasorum neovascularization in experimental hypercholesterolemia
Journal of the American College of Cardiology, 2002Co-Authors: Joerg Herrmann, David R. Holmes, Erik L. Ritman, Lilach O Lerman, Patricia J.m. Best, Amir LermanAbstract:Abstract Objectives The purpose of this study was to test the hypothesis that endothelin (ET) receptor antagonism reduces coronary Vasa Vasorum neovascularization in experimental hypercholesterolemia. Background Experimental hypercholesterolemia is associated with increased expression of ET-1, an endothelium-derived peptide with vasoconstricting, mitogenic and angiogenic properties, in the coronary arterial wall as well as with Vasa Vasorum neovascularization. A pathomechanistic role of the endogenous ET system in Vasa Vasorum neovascularization in hypercholesterolemia has, however, remained uncertain so far. Methods Female domestic pigs were placed on a normal diet (N; n = 7) or on a hypercholesterolemic diet without (HC; n = 6) or with ET-A receptor antagonism (ABT-627, 4 mg/kg/day; HC + ET-A; n = 6). After 12 weeks, coronary Vasa Vasorum structure was assessed by three-dimensional microscopic computed tomography, expression of vascular endothelial growth factor (VEGF) within the coronary arterial wall by Western blotting and immunostaining. Results Compared with the N group, plasma concentrations of low-density lipoprotein cholesterol were higher in both the HC and HC + ET-A groups (36 ± 3 mg/dl vs. 312 ± 153 mg/dl and 303 ± 113 mg/dl, p 2 vs. 2.5 ± 1.5 per mm 2 ; p 2 ). In parallel, increase in VEGF expression in the coronary arterial wall in the HC group was preserved in the HC + ET-A group. Conclusions The current study demonstrates that chronic endothelin receptor antagonism prevents the increase in VEGF expression and Vasa Vasorum density of coronary arteries in experimental hypercholesterolemia. These findings support a role for the endogenous ET system in Vasa Vasorum neovascularization in early coronary atherosclerosis.
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coronary Vasa Vasorum neovascularization precedes epicardial endothelial dysfunction in experimental hypercholesterolemia
Cardiovascular Research, 2001Co-Authors: Joerg Herrmann, David R. Holmes, Erik L. Ritman, Lilach O Lerman, Martin Rodriguezporcel, Darcy M Richardson, Amir LermanAbstract:Objective: Experimental hypercholesterolemia is associated with Vasa Vasorum neovascularization, unknown to occur before or after initial lesion formation. Thus, this study was performed to determine the temporal course of neovascularization of coronary Vasa Vasorum in relation to endothelial dysfunction, a hallmark of early atherosclerosis. Methods: Female domestic pigs were fed a normal diet (Group 1), a hypercholesterolemic diet for 2 and 4 weeks (Group 2), or a hypercholesterolemic diet for 6 and 12 weeks (Group 3). In vitro analysis of relaxation response to bradykinin served as an index for epicardial endothelial function. Spatial pattern and density of coronary Vasa Vasorum were assessed by three-dimensional microscopic computed tomography. Results: Relaxation response of coronary arteries to bradykinin was normal in both Group 1 (93±6%) and Group 2 (89±7%) but impaired in Group 3 (71±11%; P <0.05 vs. Group 1 and 2). In contrast, density of coronary Vasa Vasorum was significantly higher in both Group 2 (4.88±2.45 per-mm2) and Group 3 (4.50±1.37 per-mm2) compared to Group 1 (2.97±1.37 per-mm2; P <0.05 vs. Group 2 and 3). Conclusion: This study demonstrates that coronary Vasa Vasorum neovascularization occurs within the first weeks of experimental hypercholesterolemia and prior to the development of endothelial dysfunction of the host vessel, suggesting a role for Vasa Vasorum neovascularization in the initial stage of atherosclerotic vascular disease.
Lilach O Lerman - One of the best experts on this subject based on the ideXlab platform.
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experimental hypercholesterolemia differentially affects adventitial Vasa Vasorum and vessel structure of the left internal thoracic and coronary arteries
The Journal of Thoracic and Cardiovascular Surgery, 2005Co-Authors: Offer Galili, Joerg Herrmann, Lilach O Lerman, Katherine J. Sattler, Julie Woodrum, Monica Olson, Amir LermanAbstract:Objective Atherosclerosis is a chronic and diffuse disease that affects all vascular beds. However, some vascular beds are more prone to atherosclerosis than others. Recent evidence suggests a role for the Vasa Vasorum in the atherosclerotic process. We hypothesized that there is a difference in adventitial Vasa Vasorum structure between the left internal thoracic artery and the coronary artery. Hence the current study was designed to characterize and compare the structure of the adventitial Vasa Vasorum in the left internal thoracic and coronary arteries. Methods Samples of vessels were obtained from female crossbred domestic pigs maintained on a normal (n = 6) or high-cholesterol (n = 6) diet for 12 weeks. The samples were scanned with micro-computed tomography, and the tomographic images were reconstructed and analyzed to obtain lumen area, vessel wall area, Vasa Vasorum count, Vasa Vasorum density, mean diameter of first- and second-order Vasa Vasorum, and second-order/first-order Vasa Vasorum ratio. Results Vasa Vasorum density was significantly higher in the coronary arteries versus that seen in the left internal thoracic arteries in the normal group, as well as in the high-cholesterol group. The higher Vasa Vasorum density in the high-cholesterol group versus that in the normal group was significant for both vessels, being more pronounced in the left internal thoracic artery. Lumen area and second-order/first-order Vasa Vasorum ratio were higher in the high-cholesterol group than in the normal group only in the left internal thoracic artery. Conclusion This study demonstrated that low Vasa Vasorum spatial density and higher lumen area observed in the left internal thoracic artery compared with that seen in the native coronary artery can be the structural background for the low incidence of atherosclerosis in this vessel.
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Experimental hypercholesterolemia differentially affects adventitial Vasa Vasorum and vessel structure of the left internal thoracic and coronary arteries.
The Journal of thoracic and cardiovascular surgery, 2005Co-Authors: Offer Galili, Joerg Herrmann, Lilach O Lerman, Katherine J. Sattler, Julie Woodrum, Monica Olson, Amir LermanAbstract:Atherosclerosis is a chronic and diffuse disease that affects all vascular beds. However, some vascular beds are more prone to atherosclerosis than others. Recent evidence suggests a role for the Vasa Vasorum in the atherosclerotic process. We hypothesized that there is a difference in adventitial Vasa Vasorum structure between the left internal thoracic artery and the coronary artery. Hence the current study was designed to characterize and compare the structure of the adventitial Vasa Vasorum in the left internal thoracic and coronary arteries. Samples of vessels were obtained from female crossbred domestic pigs maintained on a normal (n = 6) or high-cholesterol (n = 6) diet for 12 weeks. The samples were scanned with micro-computed tomography, and the tomographic images were reconstructed and analyzed to obtain lumen area, vessel wall area, Vasa Vasorum count, Vasa Vasorum density, mean diameter of first- and second-order Vasa Vasorum, and second-order/first-order Vasa Vasorum ratio. Vasa Vasorum density was significantly higher in the coronary arteries versus that seen in the left internal thoracic arteries in the normal group, as well as in the high-cholesterol group. The higher Vasa Vasorum density in the high-cholesterol group versus that in the normal group was significant for both vessels, being more pronounced in the left internal thoracic artery. Lumen area and second-order/first-order Vasa Vasorum ratio were higher in the high-cholesterol group than in the normal group only in the left internal thoracic artery. This study demonstrated that low Vasa Vasorum spatial density and higher lumen area observed in the left internal thoracic artery compared with that seen in the native coronary artery can be the structural background for the low incidence of atherosclerosis in this vessel.
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Chronic endothelin receptor antagonism prevents coronary Vasa Vasorum neovascularization in experimental hypercholesterolemia
Journal of the American College of Cardiology, 2002Co-Authors: Joerg Herrmann, David R. Holmes, Erik L. Ritman, Lilach O Lerman, Patricia J.m. Best, Amir LermanAbstract:The purpose of this study was to test the hypothesis that endothelin (ET) receptor antagonism reduces coronary Vasa Vasorum neovascularization in experimental hypercholesterolemia. Experimental hypercholesterolemia is associated with increased expression of ET-1, an endothelium-derived peptide with vasoconstricting, mitogenic and angiogenic properties, in the coronary arterial wall as well as with Vasa Vasorum neovascularization. A pathomechanistic role of the endogenous ET system in Vasa Vasorum neovascularization in hypercholesterolemia has, however, remained uncertain so far. Female domestic pigs were placed on a normal diet (N; n = 7) or on a hypercholesterolemic diet without (HC; n = 6) or with ET-A receptor antagonism (ABT-627, 4 mg/kg/day; HC + ET-A; n = 6). After 12 weeks, coronary Vasa Vasorum structure was assessed by three-dimensional microscopic computed tomography, expression of vascular endothelial growth factor (VEGF) within the coronary arterial wall by Western blotting and immunostaining. Compared with the N group, plasma concentrations of low-density lipoprotein cholesterol were higher in both the HC and HC + ET-A groups (36 +/- 3 mg/dl vs. 312 +/- 153 mg/dl and 303 +/- 113 mg/dl, p < 0.01). Vasa Vasorum density was higher in the HC group compared with the N group (4.7 +/- 1.8 per mm(2) vs. 2.5 +/- 1.5 per mm(2); p < 0.05) and was preserved in the HC + ET-A group (3.2 +/- 0.7 per mm(2)). In parallel, increase in VEGF expression in the coronary arterial wall in the HC group was preserved in the HC + ET-A group. The current study demonstrates that chronic endothelin receptor antagonism prevents the increase in VEGF expression and Vasa Vasorum density of coronary arteries in experimental hypercholesterolemia. These findings support a role for the endogenous ET system in Vasa Vasorum neovascularization in early coronary atherosclerosis.
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chronic endothelin receptor antagonism prevents coronary Vasa Vasorum neovascularization in experimental hypercholesterolemia
Journal of the American College of Cardiology, 2002Co-Authors: Joerg Herrmann, David R. Holmes, Erik L. Ritman, Lilach O Lerman, Patricia J.m. Best, Amir LermanAbstract:Abstract Objectives The purpose of this study was to test the hypothesis that endothelin (ET) receptor antagonism reduces coronary Vasa Vasorum neovascularization in experimental hypercholesterolemia. Background Experimental hypercholesterolemia is associated with increased expression of ET-1, an endothelium-derived peptide with vasoconstricting, mitogenic and angiogenic properties, in the coronary arterial wall as well as with Vasa Vasorum neovascularization. A pathomechanistic role of the endogenous ET system in Vasa Vasorum neovascularization in hypercholesterolemia has, however, remained uncertain so far. Methods Female domestic pigs were placed on a normal diet (N; n = 7) or on a hypercholesterolemic diet without (HC; n = 6) or with ET-A receptor antagonism (ABT-627, 4 mg/kg/day; HC + ET-A; n = 6). After 12 weeks, coronary Vasa Vasorum structure was assessed by three-dimensional microscopic computed tomography, expression of vascular endothelial growth factor (VEGF) within the coronary arterial wall by Western blotting and immunostaining. Results Compared with the N group, plasma concentrations of low-density lipoprotein cholesterol were higher in both the HC and HC + ET-A groups (36 ± 3 mg/dl vs. 312 ± 153 mg/dl and 303 ± 113 mg/dl, p 2 vs. 2.5 ± 1.5 per mm 2 ; p 2 ). In parallel, increase in VEGF expression in the coronary arterial wall in the HC group was preserved in the HC + ET-A group. Conclusions The current study demonstrates that chronic endothelin receptor antagonism prevents the increase in VEGF expression and Vasa Vasorum density of coronary arteries in experimental hypercholesterolemia. These findings support a role for the endogenous ET system in Vasa Vasorum neovascularization in early coronary atherosclerosis.
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coronary Vasa Vasorum neovascularization precedes epicardial endothelial dysfunction in experimental hypercholesterolemia
Cardiovascular Research, 2001Co-Authors: Joerg Herrmann, David R. Holmes, Erik L. Ritman, Lilach O Lerman, Martin Rodriguezporcel, Darcy M Richardson, Amir LermanAbstract:Objective: Experimental hypercholesterolemia is associated with Vasa Vasorum neovascularization, unknown to occur before or after initial lesion formation. Thus, this study was performed to determine the temporal course of neovascularization of coronary Vasa Vasorum in relation to endothelial dysfunction, a hallmark of early atherosclerosis. Methods: Female domestic pigs were fed a normal diet (Group 1), a hypercholesterolemic diet for 2 and 4 weeks (Group 2), or a hypercholesterolemic diet for 6 and 12 weeks (Group 3). In vitro analysis of relaxation response to bradykinin served as an index for epicardial endothelial function. Spatial pattern and density of coronary Vasa Vasorum were assessed by three-dimensional microscopic computed tomography. Results: Relaxation response of coronary arteries to bradykinin was normal in both Group 1 (93±6%) and Group 2 (89±7%) but impaired in Group 3 (71±11%; P <0.05 vs. Group 1 and 2). In contrast, density of coronary Vasa Vasorum was significantly higher in both Group 2 (4.88±2.45 per-mm2) and Group 3 (4.50±1.37 per-mm2) compared to Group 1 (2.97±1.37 per-mm2; P <0.05 vs. Group 2 and 3). Conclusion: This study demonstrates that coronary Vasa Vasorum neovascularization occurs within the first weeks of experimental hypercholesterolemia and prior to the development of endothelial dysfunction of the host vessel, suggesting a role for Vasa Vasorum neovascularization in the initial stage of atherosclerotic vascular disease.
Michael R. Dashwood - One of the best experts on this subject based on the ideXlab platform.
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A Brief Comment on Vasa Vasorum of Human Saphenous Vein: relevance for Coronary Artery Bypass Surgery.
Brazilian journal of cardiovascular surgery, 2021Co-Authors: Andrzej Loesch, Michael R. DashwoodAbstract:The importance of the Vasa Vasorum and blood supply to the wall of human saphenous vein (hSV) used for coronary artery bypass grafting (CABG) is briefly discussed. This is in the context of the possible physical link of the Vasa Vasorum connecting with the lumen of hSV and the anti-ischaemic impact of this microvessel network in the hSV used for CABG.
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Vasa Vasorum inside out/outside in communication: a potential role in the patency of saphenous vein coronary artery bypass grafts
Journal of cell communication and signaling, 2018Co-Authors: Andrzej Loesch, Michael R. DashwoodAbstract:The saphenous vein (SV) is the most commonly used conduit for revascularization in patients undergoing coronary artery bypass surgery (CABG). The patency rate of this vessel is inferior to the internal thoracic artery (ITA). In the majority of CABG procedures the ITA is removed with its outer pedicle intact whereas the (human) SV (hSV) is harvested with pedicle removed. The Vasa Vasorum, a microvessel network providing the adventitia and media with oxygen and nutrients, is more pronounced and penetrates deeper towards the lumen in veins than in arteries. When prepared in conventional CABG the vascular trauma caused when removing the hSV pedicle damages the Vasa Vasorum, a situation affecting transmural flow potentially impacting on graft performance. In patients, where the hSV is harvested with pedicle intact, the Vasa Vasorum is preserved and transmural blood flow restored at graft insertion and completion of CABG. By maintaining blood supply to the hSV wall, apart from oxygen and nutrients, the Vasa Vasorum may also transport factors potentially beneficial to graft performance. Studies, using either corrosion casts or India ink, have shown the course of Vasa Vasorum in animal SV as well as in hSV. In addition, there is some evidence that Vasa Vasorum of hSV terminate in the vessel lumen based on ex vivo perfusion, histological and ultrastructural studies. This review describes the preparation of the hSV as a bypass conduit in CABG and its performance compared with the ITA as well as how and why its patency might be improved by harvesting with minimal trauma in a way that preserves an intact Vasa Vasorum.
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Vasa Vasorum inside out outside in communication a potential role in the patency of saphenous vein coronary artery bypass grafts
Journal of Cell Communication and Signaling, 2018Co-Authors: Andrzej Loesch, Michael R. DashwoodAbstract:The saphenous vein (SV) is the most commonly used conduit for revascularization in patients undergoing coronary artery bypass surgery (CABG). The patency rate of this vessel is inferior to the internal thoracic artery (ITA). In the majority of CABG procedures the ITA is removed with its outer pedicle intact whereas the (human) SV (hSV) is harvested with pedicle removed. The Vasa Vasorum, a microvessel network providing the adventitia and media with oxygen and nutrients, is more pronounced and penetrates deeper towards the lumen in veins than in arteries. When prepared in conventional CABG the vascular trauma caused when removing the hSV pedicle damages the Vasa Vasorum, a situation affecting transmural flow potentially impacting on graft performance. In patients, where the hSV is harvested with pedicle intact, the Vasa Vasorum is preserved and transmural blood flow restored at graft insertion and completion of CABG. By maintaining blood supply to the hSV wall, apart from oxygen and nutrients, the Vasa Vasorum may also transport factors potentially beneficial to graft performance. Studies, using either corrosion casts or India ink, have shown the course of Vasa Vasorum in animal SV as well as in hSV. In addition, there is some evidence that Vasa Vasorum of hSV terminate in the vessel lumen based on ex vivo perfusion, histological and ultrastructural studies. This review describes the preparation of the hSV as a bypass conduit in CABG and its performance compared with the ITA as well as how and why its patency might be improved by harvesting with minimal trauma in a way that preserves an intact Vasa Vasorum.
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The Vasa Vasorum and Associated Endothelial Nitric Oxide Synthase Is More Important for Saphenous Vein Than Arterial Bypass Grafts
Angiology, 2012Co-Authors: Mats Dreifaldt, Domingos S. R. Souza, Andrzej Loesch, J. R. Muddle, Lennart Bodin, Xu Shiwen, A Dooley, Michael R. DashwoodAbstract:No-touch (NT) saphenous vein (SV) grafts are superior to SVs harvested by the conventional technique (CT), with a patency comparable with the internal thoracic artery (ITA). Preservation of the Vasa Vasorum is implicated in the success of NT harvesting. We compared the Vasa Vasorum and endothelial nitric oxide synthase (eNOS) in NT SV with ITA and radial artery (RA) grafts. Skeletonized SV (SSV) was also analyzed. The NT SV had a higher number and larger Vasa Vasorum compared with ITA (P = .0001) and RA (P = .0004) that correlated with eNOS protein. Activity of eNOS in SSV grafts was significantly lower than NT SV grafts (P = 004). Since a high proportion of the Vasa Vasorum are removed in SSV using the CT, we suggest that preservation of the Vasa Vasorum and eNOS-derived NO contributes to the high patency for NT as compared with SSV grafts.
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the no touch harvesting technique for vein grafts in coronary artery bypass surgery preserves an intact Vasa Vasorum
The Journal of Thoracic and Cardiovascular Surgery, 2011Co-Authors: Mats Dreifaldt, Domingos S. R. Souza, Andrzej Loesch, J. R. Muddle, Mats G. Karlsson, Derek Filbey, Lennart Bodin, Lars Norgren, Michael R. DashwoodAbstract:Objectives Our objective was to evaluate the impact of vein graft harvesting technique on structure and function of Vasa Vasorum. Methods Paired segments of great saphenous veins harvested either with conventional harvesting technique or no-touch technique were obtained from 9 consecutive patients undergoing coronary artery bypass grafting. Quantitative measurements, using immunohistochemistry and morphometry, were performed. Ultrastructural analyses of Vasa Vasorum were performed with electron microscopy. Video footage of superficial Vasa Vasorum in an implanted saphenous vein graft harvested with the no-touch technique was captured during a coronary bypass operation and is presented for online viewing. Results The total area of Vasa Vasorum in vein grafts harvested with the conventional technique was significantly reduced both in the media (P = .007) and in the adventitia ( P = .014) compared with vein grafts harvested with the no-touch technique. Ultrastructural findings indicated that the no-touch technique preserved an intact Vasa Vasorum whereas the conventional technique did not. Video footage showed retrograde flow in the Vasa Vasorum in vein graft harvested with the no-touch technique. Conclusions These findings show that the no-touch technique for saphenous vein graft harvesting for coronary bypass grafting preserves an intact Vasa Vasorum. This could represent one of the mechanisms underlying the improved patency of saphenous vein grafts harvested with this technique.
