Veins are blood vessels that carry blood back to the heart. Most veins have valves that prevent backward flow of the blood, allowing blood to move only one way, towards the heart. When these valves stop working problems develop, particularly in the legs where the effect of gravity would causes blood to pool in the veins. These veins become stretched and elongated, varicose veins. If the valves in the bigger veins, deep in the leg (the deep veins) are affected, the problem can be more severe. The condition is known as chronic venous insufficiency. Overtime this causes damage to skin, chronic swelling , changes in appearance of the leg and increases the risk of developing ulcers (Figure).
Most commonly chronic venous insufficiency is caused by diseased superficial veins, leading to varicose veins. Superfical venous insufficiency alone dose not usually progress to severe venous insufficiency or leg ulceration. The cause of varicose veins is not known, but there is a strong familial component to the condition, and hormonal changes such as occur in pregnancy can accelerate their development, as can obesity or an occupation requiring prolonged standing.
Deep venous insufficiency can occur spontaneously as part of aging; this can progress to skin damage and ultimately ulceration, and is the most common cause of leg ulcers in the elderly.
Deep venous insufficiency may also develop at any age as a complication of deep vein thrombosis. Deep vein thrombosis, where the large deep veins in the leg clot and become blocked, is associated with certain risk factors including immobility (such as long haul flights or hospitalisation), dehydration, specific blood clotting disorders, and the oral contraceptive pill. Initially the patient complains of a sore and swollen leg and once the diagnosis is made blood thinning medications are usually prescribed. Gradually over time the blocked veins re-open, but in some patients these veins no longer have functioning valves, leading to the development of deep venous insufficiency.
Moderate exercise, leg elevation at rest and compression therapy is recommended for patients with chronic venous insufficiency. Compression therapy, either bandaging (for patients with ulceration) or graduated elastic stockings, is usually essential for ulcer healing, and for preventing progression of skin damage. For patients with superficial venous insufficiency or both deep and superficial venous insufficiency, intervention may be helpful (see Interventions).
Typical Leg Ulcer