Critical Buckling Pressure of Veins

2008 ◽  
Author(s):  
Ricky Martinez ◽  
Cesar A. Fierro ◽  
Hai-Chao Han
Keyword(s):  
Critical Pressure ◽  
Varicose Veins ◽  
Axial Strain ◽  
Venous Pressure ◽  
Underlying Mechanism ◽  
Venous Hypertension ◽  
Chronic Venous Disease ◽  
Venous Disease ◽  
Jugular Veins ◽  
Critical Buckling Pressure

Vein tortuosity is often seen as a consequence of venous hypertension and chronic venous disease. However, the underlying mechanism of vein tortuosity is unclear. The aim of this study was to test the hypothesis that hypertensive pressure causes vein buckling that leads to tortuous veins. We determined the buckling pressure of porcine jugular veins and tested the mechanical properties of these veins. Our results demonstrated that veins buckle when the transmural pressure exceeds a critical pressure that is not much higher than normal venous pressure. The critical pressure was found to be strongly related to the axial strain in the veins. Our results are useful in understanding the development of varicose veins.

scholarly journals Understanding Chronic Venous Disease: A Critical Overview of Its Pathophysiology and Medical Management

2021 ◽  
Vol 10 (15) ◽  
pp. 3239
Author(s):  
Miguel A. Ortega ◽  
Oscar Fraile-Martínez ◽  
Cielo García-Montero ◽  
Miguel A. Álvarez-Mon ◽  
Chen Chaowen ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Current Knowledge ◽  
Varicose Veins ◽  
Clinical Signs ◽  
Clinical Manifestations ◽  
Significant Loss ◽  
Venous Hypertension ◽  
Chronic Venous Disease ◽  
Venous Disease ◽  
Environmental Agents

Chronic venous disease (CVD) is a multifactorial condition affecting an important percentage of the global population. It ranges from mild clinical signs, such as telangiectasias or reticular veins, to severe manifestations, such as venous ulcerations. However, varicose veins (VVs) are the most common manifestation of CVD. The explicit mechanisms of the disease are not well-understood. It seems that genetics and a plethora of environmental agents play an important role in the development and progression of CVD. The exposure to these factors leads to altered hemodynamics of the venous system, described as ambulatory venous hypertension, therefore promoting microcirculatory changes, inflammatory responses, hypoxia, venous wall remodeling, and epigenetic variations, even with important systemic implications. Thus, a proper clinical management of patients with CVD is essential to prevent potential harms of the disease, which also entails a significant loss of the quality of life in these individuals. Hence, the aim of the present review is to collect the current knowledge of CVD, including its epidemiology, etiology, and risk factors, but emphasizing the pathophysiology and medical care of these patients, including clinical manifestations, diagnosis, and treatments. Furthermore, future directions will also be covered in this work in order to provide potential fields to explore in the context of CVD.

Endovenous management of varicose veins

2004 ◽  
Vol 19 (4) ◽  
pp. 163-169 ◽  
Author(s):  
S Soumian ◽  
A H Davies
Keyword(s):  
Varicose Veins ◽  
Signs And Symptoms ◽  
Venous Hypertension ◽  
Chronic Venous Disease ◽  
Venous Disease ◽  
Foam Sclerotherapy ◽  
High Prevalence ◽  
Promising Treatment ◽  
Developed World

Objective: Chronic venous disease has made a considerable socio-economical impact in the developed world due to its high prevalence and cost of management. Venous hypertension gives rise to significant signs and symptoms that are indications for treatment. Though the mainstay of treatment currently is surgery, it may not be the ideal choice in some cases considering the heterogeneous spectrum of venous disease. Recent alternative endovenous treatments have shown a lot of promise in successfully treating this condition. The aim of this review was to assess the long-term effectiveness of these treatments. Methods: A Medline-based review of literature was carried out. Results: Foam sclerotherapy seems to be a very promising treatment for venous disease, as short-term results have shown good results in terms of outcomes, low morbidity and cost. New endovenous techniques such as radiofrequency and laser ablation are attractive considering the absence of groin scar and subsequent neovascularization, as well as very little bruising and discomfort. Conclusions: There is no clear evidence yet regarding the long-term effectiveness of these relatively new endovenous techniques.

scholarly journals Pressure dynamics in chronic venous disease

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Taimur Saleem ◽  
Seshadri Raju
Keyword(s):  
Ex Vivo ◽  
Venous Pressure ◽  
Venous Hypertension ◽  
Chronic Venous Disease ◽  
Abdominal Pressure ◽  
Venous Disease ◽  
Venous Obstruction ◽  
Resting Pressure ◽  
Air Plethysmography ◽  
Focal Stenosis

Peripheral venous pressure is regulated by central and peripheral mechanisms. Peripheral venous hypertension is an important pathologic component of chronic venous disease and is present in about two-third of patients with chronic venous disease. It can result from reflux, obstructive lesions or high arterial inflow. The dominant influence in patients with peripheral venous hypertension appears to be obstruction rather than reflux. Reflux can be superficial or deep or both. In about 70% of patients with reflux, valvular incompetence is present in the superficial, deep and perforator systems in some combination. In an ex vivo experimental model, conduit pressure increased with smaller native or functional caliber, focal stenosis and increased post-capillary inflow. Venous pressure in the lower limb can be measured in a variety of ways: supine resting pressure, erect resting pressure and ambulatory venous pressure. These measurements are affected by factors such as intra-abdominal pressure, intra-thoracic pressure, gravity, venoarteriolar reflux, valve reflux and venous obstruction. Venous obstruction is associated with elevated supine pressures while reflux is associated with elevated erect resting and ambulatory venous pressures. Ambulatory venous pressure reflects venous hypertension in patients with advanced venous disease. However, our investigation has shown that ambulatory venous pressure hypertension is rarely present if air plethysmography testing is negative. Consideration maybe given to the omission of the ambulatory venous pressure testing if air plethysmography testing is normal.

O-(β-Hydroxyethyl)-Rutosides Systemic and Local Treatment in Chronic Venous Disease and Microangiopathy: An Independent Prospective Comparative Study

Angiology ◽  
2008 ◽  
Vol 59 (1_suppl) ◽  
pp. 7S-13S ◽  
Author(s):  
Gianni Belcaro ◽  
Maria Rosaria Cesarone ◽  
Andrea Ledda ◽  
Marisa Cacchio ◽  
Irma Ruffini ◽  
...  
Keyword(s):  
Varicose Veins ◽  
Controlled Trial ◽  
Oral Treatment ◽  
Local Level ◽  
Normal Skin ◽  
Venous Pressure ◽  
Local Treatment ◽  
Chronic Venous Disease ◽  
Venous Disease ◽  
Comparable Group

O-(β-hydroxyethyl)-rutosides (HR) is used to treat chronic venous disease and signs and symptoms of chronic venous insufficiency (CVI), varicose veins, and deep venous disease. This independent prospective controlled trial (a registry study) evaluates how the efficacy of HR at the local level (perimalleolar region) can be increased by the administration of a topical HR gel. The study is based on evaluation of microcirculatory variables in patients with severe CVI (ambulatory venous pressure, >56 mm Hg) and venous microangiopathy. Patients are treated using 1 of the following 3 regimens: oral treatment with 1-g sachets of HR (2 g/d total) plus topical HR 2% gel applied 3 times daily at the internal perimalleolar region; oral treatment only (same dosage), or light elastic compression stockings. Laser Doppler skin flux at rest, skin flux at the perimalleolar region, and transcutaneous PO2 and PCO2 are measured at baseline and at the end of the treatment period. A comparable group of healthy individuals without treatment is observed for 8 weeks. In the treatment groups, flux is increased, PO2 is decreased, and PCO2 is increased compared with normal skin. At 4 and 8 weeks, the improvement in skin flux (which is decreased by all measurements), the increase in PO 2, and the decrease in PCO2 (indicating microcirculatory improvement) are statistically significantly greater in the combined oral plus topical treatment group (P < .05). No adverse effects, tolerability problems, or compliance issues are noted. These results indicate an important role of HR in the treatment and control of CVI and venous microangiopathy.

Role of ambulatory venous pressure measurement in the assessment of venous disease

2003 ◽  
Vol 18 (1) ◽  
pp. 23-29 ◽  
Author(s):  
F P Dix ◽  
C N McCollum
Keyword(s):  
Varicose Veins ◽  
Venous Pressure ◽  
Skin Condition ◽  
Venous Hypertension ◽  
Clinical Severity ◽  
Venous Disease ◽  
Duplex Imaging ◽  
Standard Assessment ◽  
Mean Pressure ◽  
Relationship Of

Objectives: The gold standard assessment of venous hypertension is ambulatory venous pressure (AVP). Aims of this study were to determine the relationship of AVP with clinical severity of venous disease and whether AVP accurately identifies sites of incompetence. Methods: 117 limbs (93 subjects) underwent classification of venous signs, duplex imaging and AVP measurement. Eleven limbs had no disease, 28 had varicose veins (VVs), 45 had chronic venous insufficiency, 15 had healed ulceration, and 18 had active ulceration. Results: Mean (standard error of the mean) pressure relief index (PRI) showed a step-wise decrease from 1794 (±317) in controls to 167 (±46) in active ulcers ( P <0.001, ANOVA). PRI correlated with clinical severity of venous disease (r = -0.60, P <0.01, Pearson). Superficial reflux alone was most common in VVs (60%), deep reflux in active ulceration (11%) and combined reflux in healed ulceration (93%). Tourniquet tests showed an increase in PRI only in combined reflux ( P <0.028, ANOVA). Conclusions: AVP correlates with skin condition but is inaccurate in identifying sites of incompetence.

scholarly journals Diagnosis and treatment of varicose veins and chronic venous insufficiency

2020 ◽  
Vol 63 (12) ◽  
pp. 756-763
Author(s):  
Shin-Seok Yang
Keyword(s):  
Surgical Treatment ◽  
Varicose Vein ◽  
Chronic Venous Insufficiency ◽  
Venous Insufficiency ◽  
Varicose Veins ◽  
Symptom Relief ◽  
Venous Pressure ◽  
Chronic Venous Disease ◽  
High Ligation ◽  
Venous Disease

This study aimed to review the pathophysiology of varicose veins and chronic venous insufficiency and the recent surgical treatment trend. Varicose veins are tortuous, twisted, or lengthened veins in the lower extremities. It is part of the spectrum of chronic venous disease. Primary pathogenesis is increased chronic venous hypertension caused by valvular insufficiency, venous outflow obstruction, and calf muscle pump failure. Some patients complain of no symptoms, except report cosmetic concerns. If the varicose vein progresses to chronic venous insufficiency, it may cause edema of the lower limb. The skin lesion can present as hyperpigmentation of the median part of the ankle, congestive dermatitis, and even a skin ulcer. The varicose vein can be diagnosed easily by visual inspection after identifying the skin lesions. For non-surgical treatment, elastic stocking, Unna boots, and pneumatic compression devices are recommended to reduce venous pressure. High ligation with stripping has been the standard treatment for varicose veins to achieve symptom relief and improve cosmetic effects. Endovenous laser ablation, radiofrequency ablation, mechanochemical ablation, and the VenaSeal closure system have been introduced as surgical treatment methods. Recently, endovenous thermal/non-thermal ablations are recommended for treatment because both are less invasive techniques. The appropriate therapy should be selected after considering the patients’ symptoms and signs, anatomical structure, and economic burden of the treatment.

scholarly journals Venous Stasis Leg Ulcers: A Review

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
David Gaus
Keyword(s):  
Venous Return ◽  
Venous Pressure ◽  
Venous Hypertension ◽  
Chronic Venous Disease ◽  
Venous Stasis ◽  
Venous Disease ◽  
Leg Ulcers ◽  
Contributing Factors ◽  
Venous Outflow ◽  
Calf Muscle Pump

Chronic venous stasis ulcers (CVSU) of the lower extremity affect up to 5% of the population over 65 years and 1.5% of the general population. CVSU is caused by chronic venous disease produced by venous hypertension. Venous hypertension results from valvular incompetence within the deep venous system, or by the obstruction of venous outflow. Both of these mechanisms produce poor venous return. Additionally, poor mobility and decreased calf muscle pump function are thought to be contributing factors. Life-long use of compressive therapy is indicated in patients with chronic venous disease in lower extremities. It reduces ambulatory venous pressure. These include bandaging systems, garments (stockings), or devices.

Chronic Venous Disease and the Leukocyte-Endothelium Interaction: From Symptoms to Ulceration

Angiology ◽  
2005 ◽  
Vol 56 (6_suppl) ◽  
pp. S11-S19 ◽  
Author(s):  
A. N. Nicolaides
Keyword(s):  
Inflammatory Process ◽  
Varicose Veins ◽  
Signs And Symptoms ◽  
Venous Hypertension ◽  
Chronic Venous Disease ◽  
Venous Disease ◽  
Vein Wall ◽  
Venous Flow ◽  
Inflammatory Cascade ◽  
The Many

The mechanisms regulating varicose vein development and the subsequent skin sequelae seen in chronic venous disease (CVD) have been investigated recently. Despite the diversity of signs and symptoms associated with the disease, it seems likely that they are related to venous hypertension. Valvular incompetence is the most important cause of venous hypertension. Recent findings suggest that inflammatory processes are involved in the structural remodeling in venous valves and in the vein wall, leading to valvular incompetence and the development of varicose veins. This has been shown by Ono and colleagues, who found infiltration of valve leaflets and the venous wall by leukocytes (monocytes and tissue macrophages) in all valve specimens from patients with CVD and in none from controls. Further work by Takase and colleagues confirmed this hypothesis. Vein wall remodeling is likely to involve the complex interplay of a range of factors, including an altered ratio between metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), and elevated levels of cytokines and growth factors favor an alteration of the extracellular matrix. Neutrophils and mast cells and their interaction with the venous endothelium are believed to play an important role in the initiation of the inflammatory response in CVD. The transmission of high venous pressures to the dermal microcirculation results in the stimulation of an inflammatory process in which cytokine and growth factor release leads to leukocyte migration into the interstitium and the initiation of further inflammatory events. This process is associated with the intense dermal fibrosis and tissue remodeling seen in chronic venous insufficiency. The many manifestations of the disease are frequently associated with symptoms usually ascribed to CVD. The proportion of patients with symptoms increases with increasing CEAP clinical classes, but the mechanisms underlying symptom appearance have not been elucidated. It has been postulated that it is related to the inflammatory cascade of events seen at all stages of CVD and in which the leukocyte and its interaction with the endothelium play a key role. It is increasingly believed that the emerging twin themes of disturbed venous flow patterns and chronic inflammation underlie and link all the manifestations of the disease. Among the many pathophysiologic mechanisms at work, the leukocyte-endothelium interactions seem to be important in many aspects of the disease and have been identified as a possible target for pharmacologic intervention. Pharmacologic agents that could attenuate various elements of the inflammatory cascade and inhibit the inflammatory process might offer a greater opportunity to prevent future morbidity. It seems reasonable to speculate that such treatment could reduce the risk of CVD progression if applied as soon as the first symptoms appear.

Duffy antigen / receptor for chemokines correlates with inflammatory reaction in rats with venous hypertension: implication for the pathogenesis of primary chronic venous disease

VASA ◽  
2014 ◽  
Vol 43 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Weibin Huang ◽  
Weiwei Qin ◽  
Lei Lv ◽  
Haoyv Deng ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Early Stage ◽  
Antigen Receptor ◽  
Venous Hypertension ◽  
Skin Tissue ◽  
Chronic Venous Disease ◽  
Venous Disease ◽  
Dependent Manner ◽  
Time Points ◽  
Duffy Antigen

Background: Duffy antigen / receptor for chemokines (DARC) possesses high affinity for several chemokine subgroups of CC and CXC. Although DARC has been shown to play a role in many inflammatory diseases, its effect on chronic venous disease (CVD) remains unidentified. We explored whether the expression of DARC in skin tissue was activated under venous hypertension as well as the relationships between DARC and inflammation. Materials and methods: The inflammation in a rat model of venous hypertension caused by a femoral arterial-venous fistula (AVF) was studied. At specified intervals the pressure in the femoral veins was recorded within 42 days. Hindlimb skin specimens were harvested at different time points. The expressions of DARC, interleukin-8 (IL-8), and monocyte chemotactic protein-1 (MCP-1) in skin tissue were examined. Mononuclear cells infiltrated in skin tissue were detected. Results: Femoral venous pressures in AVF groups increased significantly at different time points (P < 0.01). DARC was expressed in skin tissue and its expression level increased significantly in AVF groups from the 7nd day on and was enhanced in a time-dependent manner within 42 days (P < 0.05). Meanwhile, both MCP-1 and IL-8 had higher levels, accompanied by increased mononuclear cells infiltrating into skin tissue (P < 0.05). Conclusions: A rat AVF model which can maintain venous hypertension for at least 42 days is competent for researching the pathogenesis of CVD. DARC, which plays a role in the inflammation of skin tissue under venous hypertension, may become a new molecular target for diagnosis and treatment of CVD at a very early stage.

scholarly journals Dysregulations of MicroRNA and Gene Expression in Chronic Venous Disease

2020 ◽  
Vol 9 (5) ◽  
pp. 1251 ◽  
Author(s):  
Daniel P. Zalewski ◽  
Karol P. Ruszel ◽  
Andrzej Stępniewski ◽  
Dariusz Gałkowski ◽  
Jacek Bogucki ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mononuclear Cells ◽  
Varicose Veins ◽  
Expression Profiles ◽  
Lower Limbs ◽  
Chronic Venous Disease ◽  
Venous Disease ◽  
Operating Characteristics ◽  
Potential Biomarker ◽  
Pathologic Features

Chronic venous disease (CVD) is a vascular disease of lower limbs with high prevalence worldwide. Pathologic features include varicose veins, venous valves dysfunction and skin ulceration resulting from dysfunction of cell proliferation, apoptosis and angiogenesis. These processes are partly regulated by microRNA (miRNA)-dependent modulation of gene expression, pointing to miRNA as a potentially important target in diagnosis and therapy of CVD progression. The aim of the study was to analyze alterations of miRNA and gene expression in CVD, as well as to identify miRNA-mediated changes in gene expression and their potential link to CVD development. Using next generation sequencing, miRNA and gene expression profiles in peripheral blood mononuclear cells of subjects with CVD in relation to healthy controls were studied. Thirty-one miRNAs and 62 genes were recognized as potential biomarkers of CVD using DESeq2, Uninformative Variable Elimination by Partial Least Squares (UVE-PLS) and ROC (Receiver Operating Characteristics) methods. Regulatory interactions between potential biomarker miRNAs and genes were projected. Functional analysis of microRNA-regulated genes revealed terms closely related to cardiovascular diseases and risk factors. The study shed new light on miRNA-dependent regulatory mechanisms involved in the pathology of CVD. MicroRNAs and genes proposed as CVD biomarkers may be used to develop new diagnostic and therapeutic methods.

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