Varicose Veins and Arteriovenous Shunts: A Review

1990 ◽  
Vol 5 (2) ◽  
pp. 77-83 ◽  
Author(s):  
H. J. Scott
Keyword(s):  
Varicose Veins ◽  
Haemodynamic Effects ◽  
Predisposing Factors ◽  
Bowel Habit ◽  
Arteriovenous Anastomoses ◽  
Vein Wall ◽  
Arteriovenous Shunts ◽  
Causative Factors

The pathogenesis of the development of varicose veins remains obscure, and there have been many theories suggesting the primary cause. Recognized predisposing factors include age, sex, race, weight, height, pregnancy, diet, erect stance, clothes, alcohol, heredity, bowel habit and occupation. However the primary causative factors have centred around vein wall weaknesses, valvular deficiencies, and haemodynamic effects. This review looks at the evidence for and against arteriovenous anastomoses being the initiating factor in the development of varicose veins.

MATHEMATICAL MODEL AND EXPERIMENTAL ESTIMATION OF THERMAL PROCESSES IN HEATING MODULE AS A PART OF STEAM ABLATION DEVICE FOR VARICOSE VEINS TREATMENT

2021 ◽  
pp. 117-125
Author(s):  
Дина Владимировна Кривоносова ◽  
Евгений Сергеевич Ермолаев
Keyword(s):  
Mathematical Model ◽  
Varicose Veins ◽  
Thermal Power ◽  
Thermal Characteristics ◽  
Steam Injection ◽  
Heating Element ◽  
Vein Wall ◽  
Tissue Heating ◽  
Comparison Of The Results ◽  
The Mathematical Model

На сегодняшний день в России для лечения варикозного расширения вен часто проводятся малоинвазивные операции методами радиочастотной или лазерной облитерации, при этом метод паровой облитерации при лечении варикозной болезни не применяется совсем. Однако метод паровой облитерации обладает существенными преимуществами: малый объём и биоинертность рабочей среды - водяного пара, его невысокая температура - 120 °С, исключающая вероятность образования нагара и перфорации венозной стенки. Целью данной работы является разработка математической модели для расчёта тепловых характеристик блока нагревания, входящего в устройство для лечения варикозной болезни методом паровой облитерации. Модель описывает теплообменные процессы в гидравлической трубке блока нагревания и может быть полезна при расчёте размеров нагревательного элемента, обеспечивающих нагрев и парообразование определённой порции воды. С целью верификации математической модели результаты моделирования были сопоставлены с экспериментальными данными. Была проведена серия экспериментов, в ходе которых были получены значения энергии, содержащейся в одной инжекции пара, и объём воды в одной инжекции, а также оценена фактическая тепловая мощность нагревателя. Сравнение результатов имитационного моделирования и значения фактической тепловой мощности пара, полученной экспериментальным путем, показала работоспособность математической модели. Разработанная математическая модель позволяет подбирать геометрические параметры нагревательного элемента в зависимости от требуемой тепловой мощности, которая должна быть обеспечена блоком нагревания, а также варьировать параметры нагревательного элемента для разной степени нагрева тканей Today in Russia minimally invasive varicose veins treatment is often performed using radiofrequency or laser ablation, while the method of steam ablation is not used at all. However, the steam ablation method has significant advantages: a small volume and biological inertness of the working substance - sterile water vapor, its low temperature - 120 °C, excluding the carbon deposits and perforation of the vein wall. The purpose of this work is to develop a mathematical model for calculating the thermal characteristics of the heating module as a part of the device for varicose veins treatment using steam ablation. The model describes heat exchange processes in the hydraulic circuit of the heating module and can be applied to calculate the dimensions of the heating module which provides heating and vaporization of a certain portion of water. In order to verify the mathematical model, the simulation results were compared with experimental data. A series of experiments were carried out in which the energy contained in one steam injection and the volume of water in one injection were estimated, as well as the actual thermal power of the heating module. Comparison of the results of simulation and the value of the actual thermal power of steam obtained experimentally showed the efficiency of the mathematical model. The proposed mathematical model allows to select the geometric parameters of the heating element depending on the required thermal power, which must be provided by the heating module, and also to vary the parameters of the heating element for different degrees of tissue heating

scholarly journals Chronic venous insufficiency after COVID-19: management of edema and pain syndromes

2021 ◽  
Vol 18 (2) ◽  
pp. 151-153
Author(s):  
F. Kh. Nizamov
Keyword(s):  
Chronic Diseases ◽  
Chronic Venous Insufficiency ◽  
Venous Insufficiency ◽  
Clinical Symptoms ◽  
Varicose Veins ◽  
Clinical Manifestations ◽  
Pain Syndrome ◽  
Venous Stasis ◽  
Vein Wall ◽  
Vas Scores

Introduction. COVID-19 infection raises many questions regarding the health condition of patients after they have had COVID-19. The aim of this study is to examine the characteristic symptoms of chronic venous insufficiency in the postcovid period.Materials and methods. The materials that were used for work included the results of studying the medical aid appealability, characteristic symptoms, diagnosis and treatment of symptoms of chronic venous insufficiency in persons who have had the coronavirus infection. 47 patients presented with complaints about deterioration of their condition after they had had COVID-19 over March to September 2021 period. Methods: general clinical examiniation, ultrasound angioscanning of veins of the lower extremities, laboratory coagulation tests.Results and discussion. Before deterioration, calf circumference was measured 22–24 cm at a typical measurement site in most patients (89%), after covid infection it reached 26–27 cm. Varicose veins remained soft, without intravascular formations, edema was often bilateral, asymmetric, pain was described as constant (5–6 VAS scores), patients had prominent signs of lymphostasis. 35 out of 47 people received diosmin-based venotonic drug of Russian manufacture at a dose of 1000 mg/day (one tablet twice a day), the course of treatment lasted one to two months. After that period, the edema subsided in 85% of patients, the severity of pain syndrome significantly reduced (up to 2–3 VAS scores). With regard to chronic venous insufficiency in patients with chronic diseases of lower extremity veins (mostly varicose and post-thrombotic diseases), the significant progress of disease was observed in almost 94% of follow-up cases. Diosmin is the main drug that is prescribed to treat chronic venous insufficiency. The drug has an angioprotective and venotonic effect, reduces the vein wall elasticity, increases venous tone, and decreases venous stasis, reduces capillary permeability and fragility, and increases their resistance, improves microcirculation and lymphatic drainage.Сonclusions. In the postcovid period, clinical symptoms of some chronic diseases occur/worsen, including clinical manifestations of chronic venous insufficiency. The use of Russian diosmin-based drug for the management of edema and pain syndrome is very promising.

scholarly journals The State of the Hemomycocirculatory Bed of Adventitia of Varicose Veins of the Small Pelvis in Women with Chronic Inflammatory Diseases of the Internal Genital Organs

2017 ◽  
Vol 23 (2) ◽  
Author(s):  
Natalya Drohomyretska
Keyword(s):  
Inflammatory Diseases ◽  
Varicose Veins ◽  
Morphological Changes ◽  
Complex Structure ◽  
The State ◽  
Reproductive Age ◽  
Ovarian Vein ◽  
Women Of Reproductive Age ◽  
Vein Wall ◽  
Inflammatory Processes

Hemomicrocirculatory system – is a complex structure that reacts in every pathological process even before the clinical period and takes the first blow. The study of microhemocirculation will provide an opportunity to solve the important for practical medicine questions of pathogenesis of many diseases, as for the prevention and treatment of regional disorders of blood circulation.The objective of the research is to study the state of the hemomicrocirculatory bed (HMCB) of adventitia of varicose veins of the small pelvis (VVSP) in women with chronic inflammatory processes of the organs of the small pelvis (CIPOSP).Materials and methods of research. To evaluate the restructuring of the HMCB of adventitia of VVSP, the operating material of 12 women of reproductive age was used. Mainly, there were pieces of the ovarian vein. The study of the HMCB in the vein wall was performed by the non-injecting method of silver impregnation according to V.V. Kupriyanov. To standardize the results, the condition of the HMCB of adventitia of the venous wall in norm was studied in 5 women of reproductive age, who died as a result of various traumas.Results of the research. After the performed studies, the structural-morphological changes of the HMCB of the adventitia of the small pelvis veins were revealed. The dilation of capillaries, postcapillaries, postcapillary venules was observed. The diameter of the vessels of the HMCB of the ovarian vein adventitia was: venule – 94.21 ± 1.38 μM in comparison with the norm – 48.78 ± 1.60 μM (p<0.001); post-capillary venules – 46.76 ± 1.04 μM in comparison with the norm – 28.29 ± 1.1.01 μM (p<0.001); the capillaries were 11.22 ± 0.14 μM in comparison with the norm – 8.24 ± 0.16 μM (p<0.05), arterioles – 29.02 ± 0.76 μM in comparison with the norm – 25.19 ± 1.15 μM (p<0.01). The architectonics of the arterioles is almost unchanged. Lumen of venules is filled with formed elements. The structure of capillaries is polymorphic. The capillary net was localized and concentrated or was formed as a thick planar net, the capillaries were expanded. There were arterio-venulous anastomoses. Endothelial nuclei are shortened. In some preparations, the diameter of the arterioles corresponded to the diameter of the collection venules.  Conclusions:1. The first discovered by us changes in HMCB of adventitia of varicose veins of the small pelvis in women with CIPOSP can be one of the pathogenetic links of the development and progression of the varicose vein itself, which in turn aggravates the course of chronic inflammation.      2. The timely appointment of drugs that improve microcirculation will enable to prevent the development of dystrophic changes in the vein wall, improve the course of chronic inflammatory processes and reduce or completely eliminate the syndrome of “chronic pelvic pain”.

Changes in Metalloproteinase (MMP-1, MMP-2) Expression in the Proximal Region of the Varicose Saphenous Vein Wall in Young Subjects

2000 ◽  
Vol 15 (2) ◽  
pp. 64-70 ◽  
Author(s):  
J. Buján ◽  
F. Jurado ◽  
M. J. Gimeno ◽  
N. García-Honduvilla ◽  
G. Pascual ◽  
...  
Keyword(s):  
Saphenous Vein ◽  
Varicose Vein ◽  
Healthy Subjects ◽  
Varicose Veins ◽  
Young Patients ◽  
Proximal Region ◽  
Vein Wall ◽  
Immunohistochemical Markers ◽  
Young Subjects ◽  
Process Characteristic

Objective: An evaluation of the proteoglycan perlecan, collagen I and III, and metalloproteinases MMP−1, −2, −3 and −9 was performed to explore the possible relationships between ageing, affected vein region and reactive state of the varicose vein wall. Methods: Segments of saphenous vein were obtained from healthy subjects and from those with varicose veins. The vein specimens were subdivided according to subject age (<50/^50) and vein source (distal/proximal). Results: The walls of control vein specimens acquired a more collagenous appearance with age. These changes were not accompanied by significant modifications in the immunohistochemical markers used. In specimens from young patients, proximal varicose vein segments showed an increase in MMP-1, MMP-2 and MMP-9 expression. Subjects of more advanced age showed an increase in perlecan expression. Conclusion: This increase in MMPs could lead to the acceleration of the final fibrosclerotic process characteristic of the varicose vein wall.

Effect of TGF-beta1 on MMP/TIMP and TGF-beta1 receptors in great saphenous veins and its significance on chronic venous insufficiency

2016 ◽  
Vol 32 (5) ◽  
pp. 334-341 ◽  
Author(s):  
Pedro Serralheiro ◽  
Elisa Cairrão ◽  
Cláudio J Maia ◽  
Marina João ◽  
Carlos M Costa Almeida ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chronic Venous Insufficiency ◽  
Venous Insufficiency ◽  
Transforming Growth Factor ◽  
Varicose Veins ◽  
Bypass Graft ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Wall Structure ◽  
Vein Wall ◽  
Tgf Β1

Objectives Transforming growth factor-beta1 (TGF-β1) may participate in local chronic inflammatory processes in varicose veins and in venous wall structure modifications through regulation of matrix metalloproteinases (MMP) and their inhibitors (tissue inhibitor of metalloproteinase (TIMP)). The aim of this study was to analyze the effect of TGF-β1 in the vein wall, namely on the gene expression of selected MMP, TIMP and TGF-β1 receptors. Methods Healthy vein samples were harvested from eight subjects who underwent coronary bypass graft surgery with great saphenous vein. Each vein sample was divided into two segments, which were cultivated separately in vitro (one of the segments had TGF-β1 added) and then submitted to gene expression analysis. Results In the TGF-β1 supplemented group, there was a general increase in the mean gene expression. Specifically, expression of MMP9, MMP12, TIMP1 and TIMP2 were statistically significant. Conclusion The results of this study demonstrate that the gene expression of MMP9, MMP12, TIMP1 and TIMP2 was influenced by the addition of TGF-β1. These results may be translated to chronic venous insufficiency framework and suggest involvement of TGF-β1 in the vein wall pathology.

The selective closure of feline carotid arteriovenous anastomoses (AVAs) by GR43175

Cephalalgia ◽  
1989 ◽  
Vol 9 (9_suppl) ◽  
pp. 41-46
Author(s):  
Marion J Perren ◽  
Wasyl Feniuk ◽  
Patrick Pa Humphrey
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Peripheral Resistance ◽  
Haemodynamic Effects ◽  
Arterial Blood Flow ◽  
Arteriovenous Anastomoses ◽  
Arterial Blood ◽  
Flow Through ◽  
Carotid Arterial ◽  
Dose Dependent

The haemodynamic effects of the selective 5-HT1-like agonist GR43175 have been compared with that of ergotamine in anaesthetized cats. Both GR43175 (30–1000 μg/kg intravenously) and ergotamine (0.3–30 μg/kg intravenously) caused a dose-dependent reduction in the proportion of cardiac output passing through arteriovenous anastomoses (AVAs). However, unlike GR43175, the effect of ergotamine (30 μg/kg intravenously) was associated with marked increases in diastolic blood pressure and total peripheral resistance. In further studies, the effect of GR43175 on the distribution of blood flow within the carotid bed has been examined. GR43175 caused a reduction in total carotid arterial blood flow which was entirely due to a reduction in flow through carotid AVAs. These results demonstrate that GR43175, unlike ergotamine, has a highly selective vasoconstrictor action on AVAs within the cranial circulation of anaesthetized cats. Such a mechanism may be important in its antimigraine activity.

The role of arteriovenous shunts in the pathogenesis of varicose veins

1986 ◽  
Vol 4 (2) ◽  
pp. 124-128 ◽  
Author(s):  
Howard C. Baron ◽  
Sebastiano Cassaro
Keyword(s):  
Varicose Veins ◽  
Arteriovenous Shunts

Endocrine mechanisms in the pathogenesis of primary varicosis

Phlebologie ◽  
2013 ◽  
Vol 42 (01) ◽  
pp. 13-18 ◽  
Author(s):  
S. Schnabl ◽  
A. Strölin ◽  
Ch. Busch
Keyword(s):  
Chronic Venous Insufficiency ◽  
Regulatory Networks ◽  
Venous Insufficiency ◽  
Varicose Veins ◽  
Chronic Venous Disease ◽  
Venous Disease ◽  
Extensive Literature ◽  
Vein Wall ◽  
Extensive Literature Search ◽  
Relaxin 2

SummaryIntroduction: Varicose veins affect up to 40 % of men and up to 51 % of women. The patho-physiology of primary varicosis (chronic venous insufficiency, CVI) is poorly understood. Here, the available data on possible endocrine mechanisms in healthy and varicose veins are reviewed.Methods: An extensive literature search was conducted in PubMed using the following key words: Chronic venous insufficiency, CVI, chronic venous disease, CVD, varicosis, saphenous vein, pathogenesis, hormone.Results: Several theories ranging from incompetence of the valves to functional, biological or morphologic changes in different layers of the vein wall have been proposed. However, an increasing body of evidence suggests that endocrine mechanisms might be involved in the pathogenesis of primary varicosis. In this respect a growing number of hormones (e.g. estrogen, progesterone, relaxin-2, and oxytocin) and their receptors have been linked to primary varicosis in experimental, pharmacological and histological studies.Conclusion: In summary, endocrine-based mechanisms seem to play a role in the pathogenesis of primary varicosis. This opens up the perspective for pharmacological treatments targeting the various described endocrine regulatory networks.

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