Involvement of Varicose Veins in Superficial Venous Thrombosis

Varicose veins are usually a sign of a benign disease, however with progression of the disease and advanced age, they can lead to serious clinical problem. Beside chronic venous insufficiency, superficial venous thrombosis (SVT) represents one of the most frequent complications which can complicate with deep venous thrombosis (DVT) and pulmonary embolism. Classical risk factors for SVT are similar as for DVT. However, varicose veins represent one of the most important risk factors for the development of SVT. In varicose veins blood flow is usually turbulent, with increased shear stress which causes vascular damage, resulting in endothelial dysfunction and structural deterioration of vessel wall accompanied by inflammatory response. Because of changes in hemodynamic conditions, in varicose veins the constitution of blood is changed. In varicose veins haematocrit level is increased and consequently blood viscosity. Further, in the blood of varicose veins circulating inflammatory markers are increased, as well as circulating markers of endothelial damage. There is also imbalance between the pro-and anticoagulant factors and between pro-and antifibrinolytic agents favouring hypercoagulable microenvironment. Therefore, varicose veins represent the highest risk for development of SVT.