Section 3. Heart and Blood Vessel Disorders

Chapter 36. Venous Disorders

Introduction | Deep Vein Thrombosis | Superficial Thrombophlebitis | Varicose Veins | Arteriovenous Fistula

Varicose Veins

Varicose veins are abnormally enlarged superficial veins in the legs.

The precise cause of varicose veins is unknown, but the main problem is probably a weakness in the walls of superficial veins. This weakness may be inherited. Over time, the weakness causes the veins to lose their elasticity. They stretch and become longer and wider. To fit in the same space that they occupied when they were normal, the elongated veins become convoluted. They may appear as a snakelike bulge beneath the skin. Varicose veins often develop during pregnancy and resolve shortly after childbirth.

More important than the elongation is the widening of the veins, which causes the valve cusps to separate. When the person stands, the blood is pulled backward by gravity and is not stopped because the valve cusps are separated. Thus, blood flows backward, rapidly filling the veins. The backward flow of blood causes the thin-walled, convoluted veins to enlarge even more. Some of the connecting veins, which normally allow blood to flow only from the superficial veins into the deep veins, also enlarge. If they enlarge, their valve cusps also separate. Consequently, blood squirts backward into the superficial veins when the muscles squeeze the deep veins, causing the superficial veins to stretch further.

See the figure Valves in Varicose Veins.

Many people with varicose veins also have spider veins, which are enlarged capillaries. Spider veins may be caused by the pressure from blood in varicose veins, but the cause is generally thought to be hormonal factors that are not yet understood. A hormonal cause would explain why spider veins most commonly occur in women, particularly during pregnancy.

Symptoms and Complications

Besides being unsightly, varicose veins commonly ache and make the legs feel tired. However, many people, even some with very large veins, have no pain. The lower part of the leg and ankle may itch, especially if the leg is warm after a person has been wearing socks or stockings. Itching can lead to scratching and can cause redness or a rash, which is often incorrectly attributed to dry skin. The pain is sometimes worse when varicose veins are developing than when they are fully stretched.

Only a small percentage of people with varicose veins have complications, such as dermatitis, inflammation of the veins (phlebitis), or bleeding. Dermatitis produces a red, scaling, itchy rash or a brown area, usually on the inside of the leg above the ankle. Scratching or a minor injury, particularly from shaving, can cause bleeding or development of a painful ulcer that does not heal. Ulcers may also bleed. Phlebitis may occur spontaneously or result from an injury. Although usually painful, phlebitis that occurs with varicose veins is rarely harmful.

Diagnosis

Varicose veins can usually be seen bulging under the skin, but symptoms may develop before the veins become visible. When varicose veins are not visible, doctors experienced in checking for them can palpate the leg to determine the extent of the problem.

X-rays or ultrasonography may be performed to assess the functioning of the deep veins. Usually, such procedures are necessary only if malfunction of the deep veins is suggested by changes in the skin or by swollen ankles. The ankles swell because fluid accumulates in the tissue under the skin--a condition called edema. Varicose veins alone do not cause edema.

Treatment

Although individual varicose veins can be removed or eliminated by surgery or injection therapy, the disorder cannot be cured. Thus, treatment mainly relieves symptoms, improves appearance, and prevents complications. Elevating the legs--by lying down or using a footstool when sitting--relieves the symptoms of varicose veins but does not prevent new varicose veins from forming. Usually, varicose veins that appear during pregnancy largely subside during the 2 or 3 weeks after delivery. During this time, they should not be treated.

Elastic stockings (support hose) compress the veins and prevent them from stretching and hurting. People who do not want surgery or injection therapy or who have a medical condition that prevents them from having these treatments may choose to wear elastic stockings.

Surgery: Surgery aims to remove as many of the varicose veins as possible. However, surgeons try to preserve the saphenous vein because it can be used as a bypass graft if coronary artery or peripheral artery disease develops. This vein is the longest superficial vein in the body, extending from the ankle to the groin, where it joins the femoral vein (the main deep vein in the leg). If the saphenous vein must be removed, a procedure called stripping is performed. The surgeon makes two incisions, one at the groin and one at the ankle, and opens the vein at each end. A flexible wire is threaded through the entire vein and then pulled out to remove the vein.

To remove other varicose veins, the surgeon makes incisions in other areas. Because the superficial veins play a less significant role than the deep veins in returning blood to the heart, their removal does not impair circulation if the deep veins are functioning normally.

Removal of varicose veins is a lengthy procedure, so the person is usually given a general anesthetic. This procedure relieves the symptoms and prevents complications, but it leaves scars. The more extensive the procedure, the longer the time before new varicose veins develop. However, removal of varicose veins does not eliminate the tendency to develop new varicose veins.

Injection Therapy (Sclerotherapy): An alternative to surgery is injection therapy, which seals the veins, so that blood can no longer flow through them. A solution is injected into the vein to irritate it and produce a thrombus. In essence, this procedure produces a harmless kind of superficial thrombophlebitis. Healing of the thrombus leads to formation of scar tissue, which blocks the vein. However, the thrombus may dissolve instead of becoming scar tissue, and the varicose vein then reopens.

Injection therapy was common in the United States between the 1930s and 1950s but fell out of favor because of poor results and complications. Current techniques are more likely to be successful and are safe for varicose veins of all sizes.

Current techniques include special bandaging that reduces the size of the thrombus by compressing the diameter of the injected vein. A smaller thrombus is more likely to form scar tissue, as desired. A further advantage of this technique is that adequate compression virtually eliminates the pain usually associated with superficial phlebitis.

Although injection therapy is more time-consuming than surgery, it has several advantages: Anesthesia is not necessary, new varicose veins can be treated as they develop, and people can go about their normal daily activities between treatments. However, even with current techniques, some doctors consider injection therapy only when varicose veins return after surgery or when a person desires cosmetic improvement.

If spider veins cause pain or a burning sensation or are unsightly, they also may be treated with injection therapy.

Laser Therapies: Laser therapy is being used experimentally by some surgeons for the treatment of varicose veins. This therapy uses a highly focused, continuous stream of high-intensity light to cut or destroy tissue. However, the usefulness of this therapy has not yet been determined. Intense pulsed light therapy can be used to treat small spider veins. This therapy is similar to laser therapy except that the light is applied in pulses.