The valvular apparatus in venous insufficiency: a problem of quantity?

Superficial Venous Disease-An Updated Review

BACKGROUND

This review article provides an updated review of a relatively common pathology with various manifestations. Superficial venous diseases (SVDs) are a broad spectrum of venous vascular disease that predominantly affects the body's lower extremities. The most serious manifestation of this disease includes varicose veins, chronic venous insufficiency, stasis dermatitis, venous ulcers, superficial venous thrombosis, reticular veins, and spider telangiectasias.

METHODS

The anatomy, pathophysiology, and risk factors of SVD were discussed during this review. The risk factors for developing SVD were related to race, age, sex, lifestyle, and certain genetic conditions as well as comorbid deep vein thrombosis. Various classification systems were listed, focusing on the most common one-the revised Clinical-Etiology-Anatomy-Pathophysiology classification. The clinical features including history and physical examination findings elicited in SVD were outlined.

RESULTS

Imaging modalities utilized in SVD were highlighted. Duplex ultrasound is the first line in evaluating SVD but magnetic resonance imaging and computed tomography venography, plethysmography, and conventional venography are feasible options in the event of an ambiguous venous duplex ultrasound study. Treatment options highlighted in this review ranged from conservative treatment with compression stockings, which could be primary or adjunctive to pharmacologic topical and systemic agents such as azelaic acid, diuretics, plant extracts, medical foods, nonsteroidal anti-inflammatory drugs, anticoagulants and skin substitutes for different stages of SVD. Interventional treatment modalities include thermal ablative techniques like radiofrequency ablationss, endovenous laser ablation, endovenous steam ablation, and endovenous microwave ablation as well as nonthermal strategies such as the Varithena (polidocanol microfoam) sclerotherapy, VenaSeal (cyanoacrylate) ablation, and Endovenous mechanochemical ablation. Surgical treatments are also available and include debridement, vein ligation, stripping, and skin grafting.

CONCLUSIONS

SVDs are prevalent and have varied manifestations predominantly in the lower extremities. Several studies highlight the growing clinical and financial burden of these diseases. This review provides an update on the pathophysiology, classification, clinical features, and imaging findings as well as the conservative, pharmacological, and interventional treatment options indicated for different SVD pathologies. It aims to expedite the timely deployment of therapies geared toward reducing the significant morbidity associated with SVD especially varicose veins, venous ulcers, and venous insufficiency, to improve the quality of life of these patients and prevent complications.

Endovenous thermal ablation of superficial truncal veins and compression therapy results in symptom relief in venous valve aplasia

Venous valve aplasia (or valvular rarefication) is a rare cause of chronic venous insufficiency. In the present report, we have described the case of a 33-year-old man with severe symmetric lower leg edema and heaviness and pain in both lower legs. Duplex ultrasound demonstrated severe venous insufficiency in the superficial and deep venous system of both legs. Further imaging examinations supported the diagnosis of venous valvular aplasia. Treatment consisted of endovenous thermal ablation of the great saphenous vein and small saphenous vein as well as consistent compression therapy, resulting in a marked reduction of his leg edema, heaviness, and pain.

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.

Postthrombotic Syndrome: Long-Term Sequela of Deep Venous Thrombosis

Postthrombotic syndrome is a common long-term complication of proximal lower extremity deep venous thrombosis, which not only significantly affects the quality of life of patients but also imposes a substantial financial burden on our healthcare system. Due to limited awareness and inability of physicians to recognize and treat this condition early, its prevalence is steadily increasing. In this article, we review the pathophysiology, the risk factors involved, diagnostic workup, and the various management options available to treat this condition.

Cellular and molecular basis of Venous insufficiency

Chronic venous disease (CVD) has a range of clinical presentations, including tortuous, distended veins in lower extremities, increasing skin pigmentation, and in severe cases ulceration of the affected skin. Venous insufficiency, a precursor to CVD characterized by improper return of blood from the lower extremities to the heart, must be studied in its earliest stages at a time when preventative measures could be applied in man. This underscores the need for basic research into biomarkers and genetic predisposing factors affecting the progression of venous disease. Investigation over the past decade has yielded insight into these specific genetic, cellular and molecular mechanisms underlying the development of venous disease. Among the many advances include the elucidation of an increasing role for matrix metalloproteinases as important mediators of the degenerative process involved with venous insufficiency. This may be preceded by an inflammatory process which further contributes to venular degeneration and endothelial dysfunction seen in advanced presentation of disease. Furthermore, genomic analyses have shed light upon temporal expression patterns of matrix remodeling proteins in diseased tissue samples. In this review we examine some of the current findings surrounding cellular, molecular and genetic advances in delineating the etiology of chronic venous disease.

Molecular mechanisms in chronic venous insufficiency

Chronic venous disease (CVD) is common. Its manifestations include varicose veins; skin changes such as dermatitis, hyperpigmentation, and lipodermatosclerosis; and chronic leg ulcers. Recent advances in the understanding of its pathophysiology have shown how molecular mechanisms in the inflammatory cascade are involved in these diverse findings. Venous hypertension and associated fluid shear stress alterations on the endothelial surface may initiate this cascade and may lead to adverse changes in the venous wall, venous valves, and skin that can eventually result in varicose veins and in venous ulcers.

Mutations in FOXC2 Are Strongly Associated With Primary Valve Failure in Veins of the Lower Limb

Background— Mutations in the FOXC2 gene cause lymphedema distichiasis, an inherited primary lymphedema in which a significant number of patients have varicose veins. Because lymphedema distichiasis is believed to be caused by lymphatic valve failure (reflux), and FOXC2 is highly expressed on venous valves in mouse embryos, we tested the hypothesis that FOXC2 mutations may be linked to venous valve failure and reflux.

Methods and Results— The venous system of the leg was investigated with Duplex ultrasound. Pathological reflux was recorded by color Duplex ultrasound in all 18 participants with a FOXC2 mutation, including 3 without lymphedema. Every participant with a mutation in FOXC2 showed reflux in the great saphenous vein (n=18), compared with only 1 of 12 referents (including 10 family members; P <0.0001, Fisher exact test). Deep vein reflux was recorded in 14 of 18 participants.

Conclusions— FOXC2 is the first gene in which mutations have been strongly associated with primary venous valve failure in both the superficial and deep veins in the lower limb. This gene appears to be important for the normal development and maintenance of venous and lymphatic valves.

Hypertension-induced venous valve remodeling

INTRODUCTION

In human beings, chronic venous insufficiency is linked to venous hypertension. This in turn is associated with venous valve incompetence. This study was designed to test the hypothesis that venous hypertension serves to initiate a process that results in the venous valve and venous wall damage observed in venous insufficiency. Material and methods Acute venous hypertension was produced by creation of an arteriovenous (AV) fistula between the femoral artery and vein in Wistar rats. At specified intervals pressure in the veins was recorded. The proximal valve containing saphenous vein was exposed, and reflux was measured from reverse blood flow through the first proximal valve. The vein was excised, valve parameters were measured, a portion was taken for morphologic investigation, and the remaining specimen was frozen in liquid nitrogen for investigation of leukocyte infiltration, expression of adhesion molecules, matrix metalloproteinase (MMP) levels, and apoptotic markers. Contralateral nonpressurized saphenous veins were used as control specimens.

RESULTS

The saphenous and femoral veins were immediately distended by pulsatile blood flow from the arterial system. Pressure was significantly increased from 11 +/- 2 mm Hg to 94 +/- 9 mm Hg. At 2 days no reflux was detected in the saphenous veins. At 1 week, one of four rats exhibited reflux; at 2 weeks, two of four rats had reflux; and at 3 weeks, three of four rats showed reflux. Contralateral saphenous veins were uniformly competent. Compared with control specimens, the veins were dilated; leaflet length and leaflet width were significantly reduced. Granulocytes, monocytes, and macrophages were identified in all regions of the vein wall, and the number was increased by the presence of the AV fistula. The number of T-lymphocytes was increased, and B-lymphocytes were present. P-selectin was upregulated in the saphenous vein walls, as was intercellular adhesion molecules. MMP-2 and MMP-9 expression in the veins was not enhanced. In the nuclear factor kappabeta family, Ikappabeta was not increased in any hypertensive veins. The number of apoptotic cells in the vein wall was increased in the presence of the AV fistula.

CONCLUSION

This study indicates that acute venous hypertension is accompanied by significant venous distention and some valve damage as early as 3 weeks after fistula creation. There is development of inflammatory markers, with leukocyte infiltration and increased adhesion molecule expression. We could not detect significant enhancement of MMP levels or nuclear transcription factors. It is uncertain whether this lack of evidence may be partially due to enhanced apoptosis in venous valves and vein walls. A detailed definition of the inflammatory reaction produced by venous hypertension should be the subject of further study. Clinical relevance Saphenous vein valves when observed at the time of vein stripping show deformities of shortening, scarring, and tearing. The current model of induced venous hypertension demonstrates early venous valve changes similar to those observed in human beings and links them to a venous hypertension-induced inflammatory reaction. Thus the model could be useful in pharmacologic testing to prevent or treat venous insufficiency and for defining the fundamental mechanisms that cause varicose veins.

Leukocyte activation in patients with venous insufficiency

PURPOSE

Cell activation may play an important role in the production of venous insufficiency, just as leukocytes participate in the cause of venous ulcer. If activated, monocytes observed on venous endothelium can migrate into the venous wall and produce toxic metabolites and free oxygen radicals that may participate in valve destruction and venous wall weakening. At present, it remains uncertain to what degree leukocytes are actually activated in patients. This study was designed to explore the level of activation and to examine whether patient plasma contains an activator that leads to leukocyte activation of unstimulated naive leukocytes from volunteers without venous insufficiency disease.

METHODS

Twenty-one patients (4 men, 17 women), who ranged in age from 34 to 69 years (mean age, 53.2 years), with chronic venous disease were compared with 16 healthy control volunteers (4 men, 12 women), who ranged in age from 18 to 65 years (mean age, 48.4 years). All the patients underwent evaluation with Doppler ultrasound scanning and were classified with the CEAP score.1 Nearly all the patients who smoked or were hypertensive were excluded. The blood types (ABO and Rh) of the controls were matched to the study group. Isolates of patient whole blood, plasma, or leukocytes were incubated with isolates of control whole blood, plasma, or leukocytes to separate actual activation from spontaneously observed activation. The granulocyte activation was measured with nitroblue tetrazolium (NBT) reduction and quantitation of granulocyte pseudopod formation. Hydrogen peroxide production in patient plasma was measured with a recently developed electrode method.

RESULTS

Leukocytes from healthy blood and patient plasma had significantly higher NBT-positive granulocyte counts than either patient blood, healthy blood, or patient blood incubated in healthy plasma. In a comparison of patient groups across the CEAP classes, the NBT-positive granulocyte counts were significantly greater in classes 4, 5, and 6 than in classes 2 and 3 (P <.001). Pseudopod formation was significantly greater in mixtures of granulocytes in healthy blood and patient plasma than in all other groups. There was no difference in the level of pseudopod formation in control leukocytes incubated with patient plasma in patients across the CEAP spectrum. The patient plasma produced significantly higher hydrogen peroxide values than did the controls.

CONCLUSION

These results suggest that patient plasma may contain an activating factor for granulocytes. The finding that activated neutrophils were fewer in number in patient whole blood than in healthy blood incubated in patient plasma could suggest that activated neutrophils in patients with chronic venous insufficiency might be trapped in the peripheral circulation. It is unknown what factors in the plasma might induce activation of naive neutrophils, but such activators could possibly be important in the pathogenesis of primary venous dysfunction and the development of chronic venous insufficiency.