Intimal changes in varicose veins: an ultrastructural study

Vicious Circle With Venous Hypertension, Irregular Flow, Pathological Venous Wall Remodeling, and Valve Destruction in Chronic Venous Disease: A Review

Substantial advances occurred in phlebological practice in the last two decades. With the use of modern diagnostic equipment, the patients' venous hemodynamics can be examined in detail in everyday practice. Application of venous segments for arterial bypasses motivated studies on the effect of hemodynamic load on the venous wall. New animal models have been developed to study hemodynamic effects on the venous system. In vivo and in vitro studies revealed cellular phase transitions of venous endothelial, smooth muscle, and fibroblastic cells and changes in connective tissue composition, under hemodynamic load and at different locations of the chronically diseased venous system. This review is an attempt to integrate our knowledge from epidemiology, paleoanthropology and anthropology, clinical and experimental hemodynamic studies, histology, cell physiology, cell pathology, and molecular biology on the complex pathomechanism of this frequent disease. Our conclusion is that the disease is initiated by limited genetic adaptation of mankind not to bipedalism but to bipedalism in the unmoving standing or sitting position. In the course of the disease several pathologic vicious circles emerge, sustained venous hypertension inducing cellular phase transitions, chronic wall inflammation, apoptosis of cells, pathologic dilation, and valvular damage which, in turn, further aggravate the venous hypertension.

Morphological restructuring of smooth muscles elements of the wallgreat saphenous vein of a person on the lower leg during the development of varicose transformation

Introduction. Further study of the structural restructuring of the wall of the great saphenous vein throughout a person’s life with the development of chronic venous diseases is an urgent task of phlebology.

The purpose of the study. Research of the morphological restructuring of smooth muscleselements of the human great saphenous vein wall on the calf in norm, ectasia and development of varicose transformation.

Materials and methods. The study of morphological restructuring of the great saphenous vein wall on the calf was carried out in 3 comparison groups by light microscopy. In 1th group, the structure of the GSV wall was studied on autopsy material of people who died from various causes at the age of 5 to 80 years. In the 2nd and 3rd groups, fragments of GSV in the calf were taken by biopsy during the execution of the operations for varicose veins. All patients underwent ultrasound mapping before surgery to determine the presence and degree of ectasia, varicose transformation and retrograde blood flow. For histological analysis in the groups, 140 GSV fragments were removed in 1-group, 165 BPV fragments in 2-group, and 250 GSV fragments in 3-group.

Results. The general morphological analysis of histological preparations made it possible to visually identify various variants of changes in smooth muscleselements inherent in the inner, middle and outer shells of the GSV wall. The selected variants of reconstruction of the smooth muscleselements were combined into 10 morphological types.

Conclusion. Age-related morphological changes in the smooth muscleselements in the GSV wall on the calf, over the course of a person’s life, do not have the same character as changes occurring in its wall during the development of its ectasia and varicose transformation.

Oberflächliche Venenthrombose der Beinvenen – Eine systematische Übersicht – Teil 1: Definition, Ätiologie, Diagnostik

Einleitung Die oberflächliche Venenthrombose (OVT) der Beinvenen ist mit einer Inzidenz von 0,5–1/1000 Einwohner/Jahr ein häufiges und mit einer Frequenz assoziierter thromboembolischer Ereignisse in bis zu 25 % der Fälle ein ernst zu nehmendes Krankheitsbild. In der vorliegenden Übersichtsarbeit sollen alle relevanten Aspekte der OVT basierend auf der aktuellen wissenschaftlichen Literatur behandelt werden.

Methoden Die systematische Übersicht umfasst das Wissen über die OVT basierend auf dem gesamten, systemisch recherchierten Erkenntnismaterial in den Datenbanken PubMed und Google Scholar. Eine Literaturrecherche in PubMed von Publikationen (1968–2018) mit den Suchbegriffen „Superficial vein thrombosis; thrombophlebitis“ ergab 102 aussagekräftige Arbeiten, die nach Vorlage der Originalarbeit ausgewertet wurden. Teil 1 der Arbeit behandelt Aspekte zur Definition, Klassifikation, Ätiologie und Diagnostik.

Ergebnisse Die OVT manifestiert sich klinisch neben den typischen Entzündungszeichen als strangförmige Induration, die Ausdruck eines thrombotischen Verschlusses epifaszialer Venen ist. Ätiologisch bedeutsam ist das Vorhandensein von Varikose (68 % der Fälle), Adipositas (23 %), Gerinnungsstörungen (18 %) und Tumorleiden (8 %). Das Durchschnittsalter der Betroffenen beträgt 62 Jahre, in 60 % der Fälle sind Frauen betroffen. Zunehmendes Lebensalter ist ein relevanter Risikofaktor. Diagnostisch ist es wichtig, das genaue Ausmaß der OVT zu beschreiben, insbesondere die Thrombuslänge und die Entfernung zum tiefen Venensystem. Dies, einschließlich der Beurteilung des tiefen Beinvenensystems, sollte bei jedem Patienten mit möglicher OVT zeitnah mittels Ultraschalldiagnostik erfolgen. Eine hier vorgeschlagene Klassifikation von 4 Ausprägungsgraden der OVT kann die Zuordnung zur aktuell empfohlenen Therapie erleichtern.

Schlussfolgerung Aufgrund der Häufigkeit und des Risikos potenziell lebensbedrohender Komplikationen sollte der OVT der Beinvenen eine größere Beachtung zukommen, insbesondere mit Blick auf eine spezialisierte Diagnostik durch Phlebologen.

The aging venous system: from varicosities to vascular cognitive impairment

Aging-induced pathological alterations of the circulatory system play a critical role in morbidity and mortality of older adults. While the importance of cellular and molecular mechanisms of arterial aging for increased cardiovascular risk in older adults is increasingly appreciated, aging processes of veins are much less studied and understood than those of arteries. In this review, age-related cellular and morphological alterations in the venous system are presented. Similarities and dissimilarities between arterial and venous aging are highlighted, and shared molecular mechanisms of arterial and venous aging are considered. The pathogenesis of venous diseases affecting older adults, including varicose veins, chronic venous insufficiency, and deep vein thrombosis, is discussed, and the potential contribution of venous pathologies to the onset of vascular cognitive impairment and neurodegenerative diseases is emphasized. It is our hope that a greater appreciation of the cellular and molecular processes of vascular aging will stimulate further investigation into strategies aimed at preventing or retarding age-related venous pathologies.

Mechanisms of Lower Extremity Vein Dysfunction in Chronic Venous Disease and Implications in Management of Varicose Veins

Chronic venous disease (CVD) is a common venous disorder of the lower extremities. CVD can be manifested as varicose veins (VVs), with dilated and tortuous veins, dysfunctional valves and venous reflux. If not adequately treated, VVs could progress to chronic venous insufficiency (CVI) and lead to venous leg ulcer (VLU). Predisposing familial and genetic factors have been implicated in CVD. Additional environmental, behavioral and dietary factors including sedentary lifestyle and obesity may also contribute to CVD. Alterations in the mRNA expression, protein levels and proteolytic activity of matrix metalloproteinases (MMPs) have been detected in VVs and VLU. MMP expression/activity can be modulated by venous hydrostatic pressure, hypoxia, tissue metabolites, and inflammation. MMPs in turn increase proteolysis of different protein substrates in the extracellular matrix particularly collagen and elastin, leading to weakening of the vein wall. MMPs could also promote venous dilation by increasing the release of endothelium-derived vasodilators and activating potassium channels, leading to smooth muscle hyperpolarization and relaxation. Depending on VVs severity, management usually includes compression stockings, sclerotherapy and surgical removal. Venotonics have also been promoted to decrease the progression of VVs. Sulodexide has also shown benefits in VLU and CVI, and recent data suggest that it could improve venous smooth muscle contraction. Other lines of treatment including induction of endogenous tissue inhibitors of metalloproteinases (TIMPs) and administration of exogenous synthetic inhibitors of MMPs are being explored, and could provide alternative strategies in the treatment of CVD.

Flow cytometric characterization of the saphenous veins endothelial cells in patients with chronic venous disease and in patients undergoing bypass surgery: an exploratory study

Recent findings have suggested that the primary factors for development of chronic venous disease (CVD), which commonly manifests as varicose veins (VV), are due to structural and biochemical modifications of the vessel wall. The aim of this exploratory study was to characterize by flow cytometry the endothelial cells (EC) mechanically extracted from the varicose saphenous veins (VSV) segments of patients submitted to VV surgery, and to compare the expression of cell surface molecules in these EC with that observed in the EC from the graft SV (GSV) of patients undergoing bypass surgery. EC were isolated from distal- (varicose trunk) and from proximal- (nearly normal) VSV segments of 30 patients submitted to VV surgery, and from proximal GSV segments of 20 patients submitted to bypass surgery (control group), using a mechanical method, and their immunophenotype was characterized by flow cytometry. EC were identified as being CD45^negCD146^brightCD31^bright, and analyzed for expression of activation-related (CD54, CD62E, CD106), procoagulant (CD142), and cell junction (CD31, CD146) molecules, and for the scavenger receptor, CD36. The EC harvested from the SV segments of CVD patients had lower expression of all the molecules evaluated, in comparison to controls; these differences were more evident for the EC isolated from the distal-VSV. The EC extracted from the proximal- and distal-VSV segments of the CVD patients also differ from each other, the first having lower levels of CD62E, CD106, CD142 and CD36. Groups did not match for gender and controls were heterogeneous concerning the underlying pathologies, which may have a confounding effect. Our study revealed that the EC isolated from varicose (distal) and nearly normal (proximal) VSV segments of the CVD patients differ phenotypically from each other, and from the EC of the control group. The VSV segments more affected by the CVD have the lowest expression of the studied markers. We hypothesize that CVD is associated with a decrease on the EC surface molecules, causing EC dysfunctionality. Further studies with a large number of gender-matched participants are needed, to confirm the results obtained in this exploratory study.

Chemokines and Growth Factors Produced by Lymphocytes in the Incompetent Great Saphenous Vein

The role of cytokines in the pathogenesis of chronic venous disease (CVD) remains obscure. It has been postulated that oscillatory flow present in incompetent veins causes proinflammatory changes. Our earlier study confirmed this hypothesis. This study is aimed at assessing chemokines and growth factors (GFs) released by lymphocytes in patients with great saphenous vein (GSV) incompetence. In 34 patients exhibiting reflux in GSV, blood was derived from the cubital vein and from the incompetent saphenofemoral junction. In 12 healthy controls, blood was derived from the cubital vein. Lymphocyte culture with and without stimulation by phytohemagglutinin (PHA) was performed. Eotaxin, interleukin 8 (IL-8), macrophage inflammatory protein 1 A and 1B (MIP-1A and MIP-1B), interferon gamma-induced protein (IP-10), monocyte chemoattractant protein-1 (MCP-1), interleukin 5 (IL-5), fibroblast growth factor (FGF), granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), platelet-derived growth factor-BB (PDGF-BB), and vascular endothelial growth factor (VEGF) were assessed in culture supernatants by a Bio-Plex assay. Higher concentrations of eotaxin and G-CSF were revealed in the incompetent GSV, compared with the concentrations in the patients' upper limbs. The concentrations of MIP-1A and MIP-1B were higher in the CVD group while the concentration of VEGF was lower. In the stimulated cultures, the concentration of G-CSF proved higher in the incompetent GSV, as compared with the patients' upper limbs. Between the groups, the concentration of eotaxin was higher in the CVD group, while the IL-5 and MCP-1 concentrations were lower. IL-8, IP-10, FGF, GM-CSF, and PDGF-BB did not reveal any significant differences in concentrations between the samples. These observations suggest that the concentrations of chemokines and GFs are different in the blood of CVD patients. The oscillatory flow present in incompetent veins may play a role in these changes. However, the role of cytokines in CVD requires further study.

The influence of age on valve disease in patients with varicose veins analysed by transmission electron microscopy and stereology

Abstract. Background: The aim of this study was to investigate the influence of age on the ultrastructure of venous valve morphology in patients with C2 classified chronic venous disorders according to the CEAP classification. Patients and methods: The study population consisted of 16 consecutive patients with varicose veins (C2). The mean age was 49.8 years (30–66). The (pre-) terminal valve including the vessel wall was harvested within the proximal 2 centimetres of the great saphenous vein. The mean thickness (volume-to-surface ratio = V/S ratio) of elastin, collagen, endothelium and of the entire valve was determined. A blinded morphologist performed the examination by transmission electron microscopy and stereology. Analyses by Pearson’s product moment correlation, Kendall’s tau and Spearman’s rank correlation were performed to investigate whether there is a correlation between age and the ultrastructural morphology. Results: Stereological analysis of the valves demonstrated a mean V/S ratio (signifying a thickness estimation) for elastin of 0.87 μm3/μm2, for collagen of 18.0 μm3/μm2, for endothelium of 0.65 μm3/μm2, and for the entire valve of 25.2 μm³/μm². Statistical analyses showed no statistically significant correlation between age and the ultrastructural morphology in this patient group. Conclusions: The ultrastructural morphology of the venous valves in chronic venous disorders may not depend on age in patients presenting with C2 disease. This conclusion may or may not apply to all C classes as we investigated a homogenous group of patients with C2 limbs.

Expression of the proinflammatory marker CD34 in varicose leg veins

Objective: To study the CD34 expression in the leg veins with primary varicose veins.

Material and Methods: The study included 18 patients with lower limbs varicose veins and deep vein valves insufficiency of C3 and C4 clinical classes (CEAP). To correct blood flow phlebectomy was accompanied by posterior tibial veins resection. Using immunohistochemistry, we compared the expression of CD34 in resected posterior tibial veins specimens and vena saphena magna distal fragment.

Results: Posterior tibial veins wall in patients with lower limb varicosity and deep veins valves insufficiency vary the CD34 degree expression comparing with the control group. Total area of expression was significantly greater than in control sample. CD34 expression area was also significantly greater in vena saphena magna than in control group. CD34 expression comparison in the specimens from patients with varicose veins showed its significantly higher degree in the vena saphena magna than in tibial veins.

Conclusion: With primary varicose veins superficial and deep leg veins develop unidirectional increase of CD34 expression, that can be assumed as a pathogenetic factors of further disease progression and involvement of deep vein valves.

Study Comparing Vein Integrity and Clinical Outcomes in Open Vein Harvesting and 2 Types of Endoscopic Vein Harvesting for Coronary Artery Bypass Grafting: The VICO Randomized Clinical Trial (Vein Integrity and Clinical Outcomes)

BACKGROUND

Current consensus statements maintain that endoscopic vein harvesting (EVH) should be standard care in coronary artery bypass graft surgery, but vein quality and clinical outcomes have been questioned. The VICO trial (Vein Integrity and Clinical Outcomes) was designed to assess the impact of different vein harvesting methods on vessel damage and whether this contributes to clinical outcomes after coronary artery bypass grafting.

METHODS

In this single-center, randomized clinical trial, patients undergoing coronary artery bypass grafting with an internal mammary artery and with 1 to 4 vein grafts were recruited. All veins were harvested by a single experienced practitioner. We randomly allocated 300 patients into closed tunnel CO₂ EVH (n=100), open tunnel CO₂ EVH (n=100), and traditional open vein harvesting (n=100) groups. The primary end point was endothelial integrity and muscular damage of the harvested vein. Secondary end points included clinical outcomes (major adverse cardiac events), use of healthcare resources, and impact on health status (quality-adjusted life-years).

RESULTS

The open vein harvesting group demonstrated marginally better endothelial integrity in random samples (85% versus 88% versus 93% for closed tunnel EVH, open tunnel EVH, and open vein harvesting; P<0.001). Closed tunnel EVH displayed the lowest longitudinal hypertrophy (1% versus 13.5% versus 3%; P=0.001). However, no differences in endothelial stretching were observed between groups (37% versus 37% versus 31%; P=0.62). Secondary clinical outcomes demonstrated no significant differences in composite major adverse cardiac event scores at each time point up to 48 months. The quality-adjusted life-year gain per patient was 0.11 (P<0.001) for closed tunnel EVH and 0.07 (P=0.003) for open tunnel EVH compared with open vein harvesting. The likelihood of being cost-effective, at a predefined threshold of £20 000 per quality-adjusted life-year gained, was 75% for closed tunnel EVH, 19% for open tunnel EVH, and 6% for open vein harvesting.

CONCLUSIONS

Our study demonstrates that harvesting techniques affect the integrity of different vein layers, albeit only slightly. Secondary outcomes suggest that histological findings do not directly contribute to major adverse cardiac event outcomes. Gains in health status were observed, and cost-effectiveness was better with closed tunnel EVH. High-level experience with endoscopic harvesting performed by a dedicated specialist practitioner gives optimal results comparable to those of open vein harvesting.

CLINICAL TRIAL REGISTRATION

URL: https://www.isrctn.com. International Standard Randomised Controlled Trial Registry Number: 91485426.

The Histopathology of Varicose Vein Disease

Varicosity is a complex venous pathology affecting the lower extremities. The exact etiology and physiopathology of varicose vein disease remain, however, unclear. Several theories exist from incompetence of the valves to a disturbance of the smooth muscle cells (SMC) and extra-cellular matrix (ECM) organization providing a weakness of the venous wall. Multiple studies have been performed to explain the underlying mechanisms of varicosity inducing alterations in the expression patterns of the endothelium, SMC, and ECM. In that respect, most attention has been focused on the alteration of the endothelium due to blood stasis and hypoxia inducing migration/proliferation of the medial SMC into the intima. Also, studies in the deformation of the ECM induced by alterations of the expression patterns of the metalloproteinases (MMP) and their inhibitors (TIMPs) have been put forward to explain the etiology of varicosity. However, less attention has been paid to the hormonal changes that occur during pregnancy and menopause, crucial factors to be involved in the etiology of varicosity. Since alteration of the estrogen receptor-b (ERb) expression could enhance directly the cellular volume of SMC and thus the disorganization of the contractile-elastic units, hypertrophy of SMC must be accounted a pivotal role that could induce the weakness of the venous wall. Altogether, this review summarizes an overview of the latest findings of varicosity with respect to the histopathological changes of the different cellular components of the varicose vein wall related to functional and morphologic alterations.

Altered elastase-alpha1-antitrypsin balance in the blood of patients with chronic venous disease

OBJECTIVES

Although leukocyte elastase is suspected to be involved in the damage of vein wall during chronic venous disease, the equilibrium between this protease and its inhibitor, alpha1-antitrypsin, has not yet been evaluated. The aim of the present study was to determine the relationship between leukocyte elastase and alpha1-antitrypsin, in the blood of patients with chronic venous disease.

PATIENTS AND METHODS

The concentration and the activity of leukocyte elastase along with the activity of alpha1-antitrypsin were evaluated in the blood of 55 chronic venous disease patients. The results were compared with those obtained in 33 healthy age and sex-matched volunteers.

RESULTS

A significant decrease in the leukocyte elastase activity that correlated with an increased alpha1-antitrypsin activity was observed in the serum of patients with mild clinical symptoms of chronic venous disease.

CONCLUSIONS

The results of the study did not confirm a hypothesis about an important role of proteolytic activity of leukocyte elastase in the vein wall injury mechanism. They show that the leukocyte elastase-alpha1-antitrypsin balance is rather shifted toward antiprotease activity, especially in an early stage of chronic venous disease.

Distribution of orientation of smooth muscle bundles does not change along human great and small varicose veins

Wall remodeling in varicose veins is associated with hypertrophy of subendothelial tissue, increase in inner diameter, wrinkling and invagination of the endothelial layer. Due to structural alterations of the wall, the smooth muscle cells (SMCs) change their original circular and longitudinal orientations. Our aim was to quantify the volume fraction of circularly, longitudinally and obliquely oriented SMCs within both the inner and outer half of the wall of 11 great saphenous varicose veins and five small saphenous varicose veins. Using stereological methods applied on cross-sections of the vessels regularly gained each 5 cm along the vessel we determined the wall thickness (846 ± 319 μm, mean ± standard deviation), the volume fraction of circular SMCs in the inner (0.19 ± 0.13) and outer (0.06 ± 0.06) layers, the volume fraction of longitudinal SMCs in the inner (0.06 ± 0.05) and outer (0.05 ± 0.04) layers, the volume fraction of oblique SMCs in the inner (0.15 ± 0.08) and outer (0.09 ± 0.08) layers, and the total volume fraction of SMCs in the inner (0.4 ± 0.1) and outer (0.21 ± 0.09) layers. The volume fraction of SMCs with circular and oblique but not with longitudinal orientation was greater in the inner layer compared to the outer layer. The SMC orientation distribution was uniform along the varicose saphenous veins. With increasing wall thickness, the volume fraction of longitudinal and oblique SMC bundles increased in both layers at the expansion of circular SMC bundles. The main differences in the orientation of the SMCs in the inner and outer wall layers should be taken into account when computational modeling of varicose saphenous veins is attempted.

Assessment of the infiltration of inflammatory cells in the walls of thrombotic varicose veins

The purpose of this study is to describe the infiltration of mast cells as well as T and B cells in the walls of thrombotic varicose great saphenous veins. Sections were obtained from venous segments of patients with varicose veins and stained with toluidine blue for mast cells, while immunohistochemistry for T cells (using CD45RO antibody) and B cells (CD20) was analyzed using light microscopy after staining. The number of mast cells, T, and B cells observed in thrombotic varicose veins was 1.925 ± 1.203, 72.038 ± 34.707, and 19.519 ± 9.899, respectively. In varicose veins, the corresponding values were 0.265 ± 0.099, 0.600 ± 0.432, and 0.488 ± 0.400. Significantly higher number of mast cells, T cells, and B cells were observed in thrombotic varicose veins compared with control veins. A significant difference was not observed between the varicose group and control group. Thrombi in varicose veins can induce infiltration of mast cells, T cells, and B cells, which may be involved in the remodeling of venous walls.

Associations of NF-kappaB and bax with apoptosis in varicose veins of women of different age groups

The study aimed at detecting apoptotic endothelial cells (ECs) and smooth muscle cells (SMCs) together with determining expression of NF-kappaB (p105/p50) and Bax in varicose vein walls. Women (n = 35) undergoing the excision of varicose veins were divided into 3 groups: younger than 35 years (I), 36–50 years (II), and older than 50 years (III). Apoptosis was determined by the TUNEL method, NF-kappaB and Bax expression by immunohistochemistry. The percentage of apoptotic ECs and SMCs in the layers of varicose vein wall increased in groups II and III. NF-kappaB expression had the lowest level in Group II with particularly low level in the media. Contrariwise, Bax expression levels in Group II were increased. The study revealed that in varicose veins ECs and SMCs apoptosis increased with advancing age. If increase in apoptosis during earlier stages of varicosities is probably regulated by intrinsic pathway, then in older patients other signaling pathways may be involved.

Morphological changes in varicocele veins: ultrastructural study

BACKGROUND

Varicocele consists of dilatation of the pampiniform venous plexus and the internal spermatic veins. It is present in 15% of male population and is a common cause of male infertility.

OBJECTIVE

To describe the normal structure of the internal spermatic vein and the morphological changes in grade 3 varicocele.

METHODS

The authors dissected and analyzed a 2- to 3-cm tract of the pampiniform venous plexus of 20 patients undergoing varicocelectomy for left varicocele and of 10 consecutive patients undergoing surgery for left inguinal hernia. The histological examination was performed with hematoxylin–eosin and Masson trichrome stains. The ultrastructural evaluation was done using both scanning and transmission electron microscopy.

RESULTS

Compared with normal internal spermatic veins, varicocele veins showed narrowing and/or obliteration of the lumens, destruction of the endothelial cells, invagination of the intima, and deposition of collagen bundles in the media (light microscopy). The ultrastructural changes in varicocele veins included elongation of the endothelial cells with features of cellular damage, loss of the internal elastic lamina, and the appearance of ghost bodies and degenerative vacuoles in the subendothelial layer.

CONCLUSIONS

The authors believe this is the first report analyzing ultrastructual changes in normal human internal spermatic vein samples and in varicocele. The underlying molecular mechanisms of these changes await further studies.

Pathogenic mechanisms in varicose vein disease: the role of hypoxia and inflammation

AIMS

Although the aetiology of varicose veins remains unknown, recent studies have focused on endothelial cell integrity and function. Among the regulatory factors of vessel tone, synthesises, pro- and anti-inflammatory, adhesion molecules and the transcription factor hypoxia inducible factor-1 alpha (HIF-1alpha), which are responsible for recruiting leukocytes, are very important.

METHODS

Investigation in this study focused on the expression of ICAM-1, E-selectin and HIF-1alpha on endothelial cells using immunostaining and RT-PCR in varicose vein specimens compared with controls.

RESULTS

Findings of this study showed alterations of the intima, such as focal intimal discontinuity and denudation of endothelium in varicose veins. Based on data derived from immunostaining and RT-PCR, no major differences were identified between ICAM-1 and E-selectin expression in varicose vein specimens compared with controls. In contrast, immunostaining results identified HIF-1alpha expression in five (5/20) varicose vein specimens, whereas no control saphenous vein specimens expressed HIF-1alpha.

CONCLUSIONS

These findings could explain other evidence of hypoxia in varicose veins. Finally, results already obtained in this investigation suggest that the process of pathogenesis of varicose veins is not restricted to the role of adhesion molecules.

Pathogenesis of primary varicose veins

BACKGROUND

Valvular incompetence and reflux are common features of primary varicose veins, and have long been thought to be their cause. Recent evidence, however, suggests that changes in the vein wall may precede valvular dysfunction.

METHODS

A literature search was performed using PubMed and Ovid using the keywords 'varicose vein wall changes', 'pathogenesis', 'aetiology' and 'valvular dysfunction'. Articles discussing the pathophysiology of complications of varicose veins, such as ulceration, recurrence, thrombophlebitis and lipodermatosclerosis, were excluded.

RESULTS AND CONCLUSION

Positive family history, age, sex and pregnancy are important risk factors for varicose vein formation. Areas of intimal hyperplasia and smooth muscle cell proliferation are often noted in varicose veins, although regions of atrophy are also present. The total elastin content in varicose as opposed to non-varicose veins is reduced; changes in overall collagen content are uncertain. Matrix metalloproteinases (MMPs), including MMP-1, MMP-2, MMP-3, MMP-7 and MMP-9, and tissue inhibitor of metalloproteinase (TIMP) 1 and TIMP-3 are upregulated in varicose veins. Activation of the endothelium stimulates the recruitment of leucocytes and the release of growth factors, leading to smooth muscle cell proliferation and migration. Dysregulated apoptosis has also been demonstrated in varicose veins. An understanding of the pathophysiology of varicose veins is important in the identification of potential therapeutic targets and treatment strategies.

Venous Reflux and Venous Distensibility in Varicose and Healthy Veins

OBJECTIVES

The aim of this study was to analyse venous diameter changes and venous reflux parameters, assessed during a standardised Valsalva manoeuvre in healthy subjects and in patients with varicose veins.

METHODS

Measurements were carried out in 444 vein segments, (96 legs of 48 healthy volunteers, 52 legs of 35 patients with varicose veins). The common femoral vein (CVF), the femoral vein (FV) and the great saphenous vein (GSV) were investigated. The parameters of reflux and the relative venous diameter change (VD diff %) were measured simultaneously during a standardised Valsalva manoeuvre.

RESULTS

Venous diameter changes during Valsalva manoeuvre (VD diff) were significantly greater in the GSV and in the deep veins of varicose patients compared to healthy subjects. The median (Interquartile range) of VD max in the CFV was: 13.1 (3.5) mm and 11.2 (3.4) mm (p=0.0002, Mann-Whitney - U test), in the FV 7.8 (2.7) mm and 6.9 (2.0) mm (p=0.01, Mann-Whitney), in the GSV: 7.3 (3.7) mm and 4.2 (1.1) mm (p<0.0001, Mann-Whitney) for the varicose and healthy veins respectively. Good correlation was seen for the retrograde peak reflux velocity (PRV) and VD diff % in varicose veins (r=0.71 (0.57 - 0.81) p<0.0001, Mann-Whitney).

CONCLUSION

Relative venous diameter--changes during a standardised Valsalva manoeuvre are significantly larger in the deep and superficial veins of varicose vein patients compared with healthy veins, the increased distensibility correlates with venous reflux parameters in varicose vein patients.

Intimal Changes in the Cephalic Vein of Renal Failure Patients before Arterio-Venous Fistula (AVF) Construction

Native cephalic vein remains the superior dialysis conduit, even thirty years after it was first described. However, up to 37% of hemodialysis patients develop progressive stenosis in the venous circuit of arterio-venous fistula (AVF), which may later cause thrombosis and occlusion. To study the pre-existing morphological changes in the wall of the cephalic vein before AVF construction, we collected 23 cephalic vein specimens from 3 normal, young trauma and twenty renal failure patients. The samples were collected at the time of vascular repair in the first group and AVF construction in the second group. Sections were prepared and stained for both light and transmission electron microscopy (TEM) examination. Compared with normal cephalic vein, all pre-access cephalic veins showed thickening of the wall and intimal hyperplasia. Other changes were loss of internal elastic lamina in 9 (45%) patients, loss of endothelial cell layer in 6 (30%), inflammatory cell infiltration of the wall in 5 (25%), mural calcification in 3 (15%) and telangiectasia in 2 (10%). Other ultrastructural changes observed were intimal hypertrophy, degeneration and loss of the endothelial cells, degeneration and fraying of smooth muscle cells (SMCs) and loss of wall components into the lumen. In conclusion, most of the apparently normal cephalic veins of renal failure patients showed morphological abnormalities at the time of AVF construction, which may well influence the outcome of shunts in terms of future stenosis and failure. It seems likely that the later development of AVF stenosis may be the result of pre-existing disease rather than the direct insult of arterialization.