scholarly journals Iliac Veins Are More Compressible Than Iliac Arteries: A New Method of Testing

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Margaret Brass ◽  
Ghassan S. Kassab
Keyword(s):  
Arterial Wall ◽  
Fluid Transport ◽  
Vascular Wall ◽  
Fluid Loss ◽  
Loading Conditions ◽  
Vein Wall ◽  
Iliac Arteries ◽  
Direct Measurements ◽  
Arterial Wall Mechanics ◽  
Venous Wall

Incompressibility implies that a tissue preserves its volume regardless of the loading conditions. Although this assumption is well-established in arterial wall mechanics, it is assumed to apply for the venous wall without validation. The objective of this study is to test whether the incompressibility assumption holds for the venous wall. To investigate the vascular wall volume under different loading conditions, inflation-extension testing protocol was used in conjunction with intravascular ultrasound (IVUS) in both common iliac arteries (n = 6 swine) and common iliac veins (n = 9 dogs). Use of IVUS allows direct visualizations of lumen dimensions simultaneous with direct measurements of outer dimensions during loading. The arterial tissue was confirmed to preserve volume during various load conditions (p = 0.11) consistent with the literature, while the venous tissue was found to lose volume (about 35%) under loaded conditions (p < 0.05). Using a novel methodology, this study shows the incompressibility assumption does not hold for the venous wall especially at higher pressures, which suggests that there may be fluid loss through the vein wall during loading. This has important implications for coupling of fluid transport across the wall and biomechanics of the wall in healthy and diseased conditions.

Passive Biaxial Mechanical Response of Aged Human Iliac Arteries

2003 ◽  
Vol 125 (3) ◽  
pp. 395-406 ◽  
Author(s):  
Christian A. J. Schulze-Bauer ◽  
Christian Mo¨rth ◽  
Gerhard A. Holzapfel
Keyword(s):  
Experimental Data ◽  
Deformation Behavior ◽  
Arterial Wall ◽  
Constitutive Models ◽  
Intraluminal Pressure ◽  
Clear Correlation ◽  
Outer Diameter ◽  
Iliac Arteries ◽  
Arterial Wall Mechanics

Inflation and extension tests of arteries are essential for the understanding of arterial wall mechanics. Data for such tests of human arteries are rare. At autopsy we harvested 10 non-diseased external iliac arteries of aged subjects (52–87 yrs). Structural homogeneity was ensured by means of ultrasound imaging, and anamneses of patients were recorded. We measured the axial in situ stretches, load-free geometries and opening angles. Passive biaxial mechanical responses of preconditioned cylindrical specimens were studied in 37°C calcium-free Tyrode solution under quasistatic loading conditions. Specimens were subjected to pressure cycles varying from 0 to 33.3kPa (250mmHg) at nine fixed axial loads, varying from 0 to 9.90N. For the description of the load-deformation behavior we employed five “two-dimensional” orthotropic strain-energy functions frequently used in arterial wall mechanics. The associated constitutive models were compared in regard to their ability of representing the experimental data. Histology showed that the arteries were of the muscular type. In contrast to animal arteries they exhibited intimal layers of considerable thickness. The average ratio of wall thickness to outer diameter was 7.7, which is much less than observed for common animal arteries. We found a clear correlation between age and the axial in situ stretch λis(r=−0.72,P=0.03), and between age and distensibility of specimens, i.e. aged specimens are less distensible. Axial in situ stretches were clearly smaller (1.07±0.09,mean±SD) than in animal arteries. For one specimen λis was even smaller than 1.0, i.e. the vessel elongated axially upon excision. The nonlinear and anisotropic load-deformation behavior showed small hystereses. For the majority of specimens we observed axial stretches smaller than 1.3 and circumferential stretches smaller than 1.1 for the investigated loading range. Data from in situ inflation tests showed a significant increase of the axial stretch with intraluminal pressure. Thus, for this type of artery the axial in situ stretch of a non-pressurized vessel is not representative of the axial in vivo stretch. None of the constitutive models were able to represent the deformation behavior of the entire loading range. For the physiological loading range, however, some of the models achieved good agreement with the experimental data.

Arterial wall properties and dietary atherosclerosis in the racing greyhound

1979 ◽  
Vol 236 (6) ◽  
pp. H790-H797 ◽  
Author(s):  
R. H. Cox ◽  
D. K. Detweiler
Keyword(s):  
Smooth Muscle ◽  
Muscle Activation ◽  
Arterial Wall ◽  
Carotid Arteries ◽  
External Diameter ◽  
Iliac Arteries ◽  
Force Development ◽  
Maximum Range ◽  
Arterial Wall Mechanics ◽  
Elastic Elements

The effects of experimental (dietary) atherosclerosis on arteries from racing greyhounds were studied. Measurements of pressure and external diameter were made on islated carotid and iliac arteries under active (norepinephrine, 5 microgram/ml) and passive (zero Ca2+ and 2 mM EGTA) smooth muscle conditions. Iliac arteries from diet-fed animals demonstrated substantial intimal lesions, but the carotid arteries were usually grossly involved. Arteries from atherosclerotic animals were stiffer during passive conditions, with the iliac arteries having the greater changes. In iliac arteries from treated animals, collagen and elastin contents were decreased, and the collagen-to-elastin ratio was increased; in carotid arteries from treated animals, elastin content was increased and the collagen-to-elastin ratio was decreased. The maximum range of control of arterial wall mechanics by smooth muscle was diminished in treated iliacs but unchanged in carotids. Both force development and constriction responses associated with smooth muscle activation were diminished in treated iliacs but unchanged in treated carotids. Mechanical properties of series elastic elements in treated iliacs were stiffer, but treated carotids were unchanged.

Comparison of arterial wall mechanics using ring and cylindrical segments

1983 ◽  
Vol 244 (2) ◽  
pp. H298-H303 ◽  
Author(s):  
R. H. Cox
Keyword(s):  
Arterial Wall ◽  
Muscle Length ◽  
Stress And Strain ◽  
Active Force ◽  
Cross Sectional ◽  
Iliac Arteries ◽  
Force Development ◽  
Arterial Wall Mechanics ◽  
Length Data ◽  
Passive Mechanics

Thin rings and intact cylindrical segments of canine carotid and iliac arteries were used to determine wall mechanics. Measurements of force and length were obtained from the ring segments, whereas measurements of pressure and diameter were obtained from the cylindrical segments under conditions of active (147 mM K+) and passive smooth muscle (Ca2+ free and 2 mM ethyleneglycolbis (beta-aminoethylether)-N,N'-tetraacetic acid). These measurements were normalized to values of segment stress and strain. Under passive conditions stress-strain relations for the rings appeared to be stiffer than those obtained using cylindrical segments. Pressure-diameter curves computed using force-length data from the rings were shifted to higher values of diameter compared with values from the intact segments at all pressure levels. Passive mechanics derived from measurements on ring segments yielded poor estimates of mechanics derived from intact segments. Despite this finding, values of active force development from the two sample geometries were similar. No statistically significant differences were found in values of maximum force development expressed in terms of sample cross-sectional area. Some differences in values of active force development at low values of muscle length were found. The latter were probably related to the differences in passive mechanics and the procedure used to normalize muscle length. Reasonable values of active force development can be obtained from ring segments.

scholarly journals BIOENERGY ASPECTS OF FUNCTIONING OF VENOUS WALL COMPONENTS (DEMONSTRATION MATERIALS OF STUDENTS AND YOUNG SCIENTISTS)

2021 ◽  
Vol 1 (4) ◽  
Author(s):  
Mykhailo Lebedyuk ◽  
Vasily Bocharov ◽  
Veronika Bocharova ◽  
Ivanna Zarychniak ◽  
Аnastasia Kovalenok
Keyword(s):  
Extracellular Matrix ◽  
Cell Function ◽  
Vascular Wall ◽  
Vascular Component ◽  
The Subject ◽  
Wall Components ◽  
Venous Wall

The subject of the study – the wall of the venous vessels of the skin. The purpose of the work is to provide demonstration and text materials of the significance of bioenergetic mechanisms of vascular wall components. The vascular component is an integral part of the pathogenesis of most dermatoses. At the same time, the bioenergetic aspects of cell function and the extracellular matrix of the vascular wall, especially venous ones, are still insufficiently taken into account, as they are the most vulnerable to inflammatory dermatoses.Key words: vascular wall components, demonstration materials.

Assessment of arterial wall stiffness by 24-hour blood pressure monitoring

2016 ◽  
Vol 88 (9) ◽  
pp. 119-124 ◽  
Author(s):  
V A Korneva ◽  
T Yu Kuznetsova
Keyword(s):  
Blood Pressure ◽  
Arterial Wall ◽  
Pulse Wave ◽  
Blood Pressure Monitoring ◽  
Vascular Wall ◽  
Pressure Monitoring ◽  
Therapeutic Practice ◽  
Wall Stiffness ◽  
The Given ◽  
Large Vessels

Arterial wall stiffness is an early marker of cardiovascular diseases. The gold standard for assessment of the stiffness of large vessels is presently pulse wave velocity (PWV). Work is in progress on the study of the reference values of PWV in people of different genders and ages. 24-hour blood pressure (BP) monitoring is not only a procedure that can estimate diurnal BP variability, but also monitor the indicators of vascular wall stiffness in a number of cases over a 24-hour period. The given review highlights the pathophysiology of arterial stiffness, methods for its assessment, and the aspects of use in therapeutic practice.

Arterial Stenting and Overdilation: Does it Change Wall Mechanics in Small-Caliber Arteries?

2002 ◽  
Vol 9 (6) ◽  
pp. 855-862 ◽  
Author(s):  
Hélène Vernhet ◽  
Roland Demaria ◽  
Jean-Marie Juan ◽  
Marie-Claire Oliva-Lauraire ◽  
Jean-Paul Senac ◽  
...  
Keyword(s):  
Arterial Wall ◽  
Rabbit Aorta ◽  
Infrarenal Aorta ◽  
Stent Deployment ◽  
New Zealand White Rabbits ◽  
Group A ◽  
Arterial Wall Mechanics ◽  
Wall Compliance ◽  
Group B ◽  
Arterial Stenting

Purpose: To evaluate changes in arterial wall mechanics induced by stent overdilation in the rabbit aorta. Methods: Twenty New Zealand white rabbits had initial stent deployment (3-mm × 8-mm Multilink) at 10% overdilation. Group A (n=11) had no subsequent balloon expansion of the stent and Group B (n=9) had 30% overdilation of the stent. A noninvasive B-mode ultrasound examination coupled with image processing allowed the measurement of systolic and diastolic diameter and the calculation of diameter compliance (Cd) and distensibility coefficient (DC) as indexes of arterial wall biomechanics. Measurements were performed before stenting in the infrarenal aorta, after initial stenting, and after stent overdilation at 3 locations: upstream, at the stent level, and downstream from the stent. Results: Cd was significantly lower in the stented aorta after initial stenting (p<0.0001) and after stent overdilation (p<0.0001) than before stenting. At the stent level, Cd and DC were significantly lower than downstream (p<0.0001) or upstream (p<0.0001) from the stent after initial stenting, as well as after stent overdilation. Downstream from the stent, Cd and DC were significantly lower after stent overdilation than before stenting (p<0.05). Conclusions: Endovascular stenting of the rabbit aorta produces a significant decrease in arterial wall compliance and distensibility. Stent overdilation is responsible for a slight additional decrease of compliance downstream from the stent.

scholarly journals Modeling the arterial wall mechanics using a novel high-order viscoelastic fractional element

2015 ◽  
Vol 39 (16) ◽  
pp. 4767-4780 ◽  
Author(s):  
J.M. Pérez Zerpa ◽  
A. Canelas ◽  
B. Sensale ◽  
D. Bia Santana ◽  
R.L. Armentano
Keyword(s):  
Arterial Wall ◽  
High Order ◽  
Arterial Wall Mechanics

scholarly journals The increasing of arterial vascular resistance is a primary factor of development isolated systolic hypertensions

2007 ◽  
Vol 13 (1) ◽  
pp. 7-13
Author(s):  
A. A. Sokolov ◽  
M. V. Soldatenko
Keyword(s):  
Arterial Stiffness ◽  
Pulse Wave Velocity ◽  
Arterial Hypertension ◽  
Vascular Resistance ◽  
Vascular Tone ◽  
Arterial Wall ◽  
Pulse Wave ◽  
Vascular Wall ◽  
Non Invasive ◽  
Modern Methods

In the submitted review value of increase of vascular resistance and a vascular tone in development of an isolated arterial hypertension has been shown. Parameters of elasticity of the arteries, used for the characteristic of properties of a vascular wall are discussed. In the review modern methods non invasive study of the properties of the arterial wall was described. The special attention has been given study of the pulse wave velocity, value of parameters of resistance and arterial stiffness for an estimation of the forecast was shown.

scholarly journals Epidemiological Research Advances in Vascular Calcification in Diabetes

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Haipeng Yao ◽  
Zhen Sun ◽  
Guangyao Zang ◽  
Lili Zhang ◽  
Lina Hou ◽  
...  
Keyword(s):  
Vascular Calcification ◽  
Ethnic Differences ◽  
Cardiovascular Events ◽  
Arterial Wall ◽  
Basic Research ◽  
Vascular Wall ◽  
Vascular Bed ◽  
Evaluation Strategies ◽  
Patients With Diabetes ◽  
Clinical Transformation

Vascular calcification is the transformation of arterial wall mesenchymal cells, particularly smooth muscle cells (SMCs), into osteoblast phenotypes by various pathological factors. Additionally, vascular transformation mediates the abnormal deposition of calcium salts in the vascular wall, such as intimal and media calcification. Various pathological types have been described, such as calcification and valve calcification. The incidence of vascular calcification in patients with diabetes is much higher than that in nondiabetic patients, representing a critical cause of cardiovascular events in patients with diabetes. Because basic research on the clinical transformation of vascular calcification has yet to be conducted, this study systematically expounds on the risk factors for vascular calcification, vascular bed differences, sex differences, ethnic differences, diagnosis, severity assessments, and treatments to facilitate the identification of a new entry point for basic research and subsequent clinical transformation regarding vascular calcification and corresponding clinical evaluation strategies.

scholarly journals Morphological changes in the venous wall under experimental neoplastic intoxication

2021 ◽  
Vol 25 (2) ◽  
pp. 205-207
Author(s):  
P. Bodnar ◽  
Ya. Bodnar ◽  
T. Bodnar ◽  
L. Bodnar
Keyword(s):  
Cancer Patients ◽  
Morphological Changes ◽  
Vascular Wall ◽  
Male Rats ◽  
Experimental Conditions ◽  
Vein Thrombosis ◽  
Oncological Diseases ◽  
Negative Effect ◽  
Thrombotic Complications ◽  
Venous Wall

Annotation. The goal of this study was to investigate the characteristic histological and morphological signs of changes in the venous wall as one of the main pathogenetic links of thrombosis in oncological pathology. Assessment of these changes is necessary to understand the process of occurrence and prevention of thromboembolic and thrombotic complications in patients with oncological diseases. Histological, submicroscopic and polarizing materials of hind limb veins of 11 mature nonlinear male rats weighing 170-180 g on day 30 of chronic neoplastic intoxication complicated by deep limb vein thrombosis were studied. It is established that experimental neoplastic intoxication in rats on histological examination was accompanied by the development of submicroscopic reorganization of endotheliocytes and their desquamation, platelet ligation as one of the causes of future thrombotic complications. Thus installed the negative effect of long-term neoplastic intoxication on the cells and all layers of the venous vascular wall as well as on the blood forming elements was studied. A close connection between the presence of the obtained changes against the background of oncological diseases and the development of such thrombotic complications as phlebothrombosis, pulmonary embolism and thrombophlebitis has been established. The development of complications shows that the prevention of thrombosis is an important component of conservative therapy of cancer patients, to prevent the development of lethal outcomes. High incidence of PE, deep vein thrombosis and thrombophlebitis in the superficial venous system emphasizes the use of preventive means of conservative treatment of cancer patients to prevent these complications, resulting in a high mortality rate. The study of morphological changes of the venous wall under the influence of chronic neoplastic intoxication in experimental conditions allows to carry out a detailed analysis of possible complications.

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