Chronic venous insufficiency is the term that usually describes patients who have disorders of the deep veins in the legs. It is possible, of course, to have chronic venous insufficiency of the superficial veins—but that is usually just called superficial venous insufficiency or varicose vein disease. In chronic venous insufficiency there are two types of disorders that can occur–obstructive disease and incompetent valve disease.
There are two conditions that produce chronic deep venous insufficiency. First, there can be a constriction or blockage of the deep veins that impedes the flow of blood back to the heart. This is somewhat similar to arteriosclerosis, which is the process that causes blockage of the arterial system. However, this type of chronic venous insufficiency is a blockage of the venous system. The second cause of chronic venous insufficiency of the deep veins is incompetent venous valves. This results in deep vein reflux, usually accompanied by chronic swelling, discoloration, and perhaps even venous ulcerations of the lower legs.
The most common cause of both types of chronic venous insufficiency—obstructive disease and incompetent valve disease—is deep vein thrombosis. Normally, a blood clot in the venous system dissolves after several days. However, if this process does not work properly, a permanent occlusion of the vein can result. There are some conditions that predispose patients to deep vein thrombosis, such as May-Thurner syndrome. This syndrome develops when the iliac artery, which is in the pelvis, compresses the iliac vein and therefore causes an obstruction of the blood returning to the heart from the legs. Another condition that results in chronic insufficiency is the congenital absence of deep vein valves.
The single most important management tool for chronic venous insufficiency is compression treatment, generally with high compression elastic surgical support stockings. While there is nothing that can cure the condition, there are a variety of other interventions that can improve the problems caused by this venous insufficiency.