Last updated: 02/17/2009

Causes of varicose veins

To understand why surgical treatment of varicose veins is sometimes necessary, it is helpful to start with a brief description of the venous system in the human body. The venous part of the circulatory system...

returns blood to the heart to be pumped to the lungs for oxygenation, in contrast to the arterial system, which carries oxygenated blood away from the heart to be distributed throughout the body. Veins are more likely than arteries to expand or dilate if blood volume or pressure increases, because they consist of only one layer of tissue; this is in contrast to arteries, in which there are three layers.

There are three major categories of veins: superficial veins, deep veins, and perforating veins. All varicose veins are superficial veins; they lie between the skin and a layer of fibrous connective tissue called fascia, which cover and support the muscles and the internal organs. The deep veins of the body lie within the muscle fascia. This distinction helps to explain why a superficial vein can be removed or closed without damage to the deep circulation in the legs. Perforating veins are veins that connect the superficial and deep veins.

Veins contain one-way valves that push blood inward and upward toward the heart against the force of gravity when they are functioning normally. The blood pressure in the superficial veins is usually low, but if it rises and remains at a higher level over a period of time, the valves in the veins begin to fail. The blood flows backward and collects in the lower veins, and the veins dilate, or expand. Veins that are not functioning properly are said to be incompetent. As the veins expand, they become more noticeable under the surface of the skin. Small veins, or capillaries, often appear as spider-shaped or tree-like networks of reddish or purplish lines under the skin. The medical term for these is telangiectasias, but they are commonly known as spider veins or thread veins. Larger veins that form flat, blue-green networks often found behind the knee are called reticular varicosities. True varicose veins are formed when the largest superficial veins become distorted and twisted by a long-term rise in blood pressure in the legs.

The most important veins in the lower leg are the two saphenous veins—the greater saphenous vein, which runs from the foot to the groin area, and the short saphenous vein, which runs from the ankle to the knee. It is thought that varicose veins develop when the valves at the top of the greater saphenous vein fail, allowing more blood to flow backward down the leg and increase the pressure on the valves in the smaller veins in turn. The practice of ligation and stripping of the greater saphenous vein is based on this hypothesis.

Some people are at increased risk for developing varicose veins. These risk factors include:

• Sex. Females in any age group are more likely than males to develop varicose veins. It is thought that female sex hormones contribute to the development of varicose veins by making the veins dilate more easily. Many women experience increased discomfort from varicose veins during their menstrual periods.
• Genetic factors. Some people have veins with abnormally weak walls or valves. They may develop varicose veins even without a rise in blood pressure in the superficial veins. This characteristic tends to run in families.
• Pregnancy. A woman's total blood volume increases during pregnancy, which increases the blood pressure in the venous system. In addition, the hormonal changes of pregnancy cause the walls and valves in the veins to soften.
• Using birth control pills.
• Obesity. Excess body weight increases the pressure on the veins.
• Occupational factors. People who have jobs that require standing or sitting for long periods of time—without the opportunity to walk or move around—are more likely to develop varicose veins.

Ambulatory phlebectomy

Ambulatory phlebectomy is the most common surgical procedure for treating medium-sized varicose veins, as of early 2003. It is also known as stab avulsion or micro-extraction phlebectomy. An ambulatory phlebectomy is performed under local anesthesia. After the patient's leg has been anesthetized, the surgeon makes a series of very small vertical incisions 1–3 mm in length along the length of the affected vein. These incisions do not require stitches or tape closure afterward. Beginning with the more heavily involved areas of the leg, the surgeon inserts a phlebectomy hook through each micro-incision. The vein segment is drawn through the incision, held with a mosquito clamp, and pulled out through the incision. This technique requires the surgeon to be especially careful when removing varicose veins in the ankle, foot, or back of the knee.

After all the vein segments have been removed, the surgeon washes the patient's leg with hydrogen peroxide and covers the area with a foam wrap, several layers of cotton wrap, and an adhesive bandage. A compression stocking is then drawn up over the wrapping. The bandages are removed three to seven days after surgery, but the compression stocking must be worn for another two to four weeks to minimize bruising and swelling. The patient is encouraged to walk around for 10–15 minutes before leaving the office; this mild activity helps to minimize the risk of a blood clot forming in the deep veins of the leg.

Transilluminated powered phlebectomy

Transilluminated powered phlebectomy (TIPP) is a newer technique that avoids the drawbacks of stab avulsion phlebectomy, which include long operating times, the risk of scar formation, and a relatively high risk of infection developing in the micro-incisions. Transilluminated powered phlebectomy performed with an illuminator and a motorized resector. After the patient has been anesthetized with light general anesthesia, the surgeon makes only two small incisions: one for the illuminating device and the other for the resector. After making the first incision and introducing the illuminator, the surgeon uses a technique called tumescent anesthesia to plump up the tissues around the veins and make the veins easier to remove. Tumescent anesthesia was originally developed for liposuction. It involves the injection of large quantities of a dilute anesthetic into the tissues surrounding the veins until they become firm and swollen.

After the tumescent anesthesia has been completed, the surgeon makes a second incision to insert the resector, which draws the vein by suction toward an inner blade. The suction then removes the tiny pieces of venous tissue left by the blade. After all the clusters of varicose veins have been treated, the surgeon closes the two small incisions with a single stitch or Steri-Strips. The incisions are covered with a gauze dressing and the leg is wrapped in a sterile compression dressing.