Stock Photo - VENOUS INSUFFICIENCY Venous reflux. The veins insure the return of the desoxygenated blood toward the heart. Numerous veins, particularly those of the limbs, possess venous valves, fold of the vein wall toward the heart. These valvules force the blood of the veins to circulate toward the heart, with no possibility to return backwards drawing on the top. If a venous valvule fails, like here at the level of the great saphenous vein of the leg drawing on the bottom, the blood is going to be able to flow back. It is the venous reflux. This venous insifficiency is at the origin of the vein dilatation and therefore of the formation of varicose veins and thrombus see image 1009307. The main factors favouring the venous valvular insufficiency are family previous history genetic predisposition, the age, the feminine sex aged women and sedentarity persons confined to bed. See. images 1007907 and 7008907 for venous insufficiency, 1008307 for the function and dysfunction of venous valves venous reflux, and 1009307 for thrombophlebitis.