Veins

Varicose Veins, Spider Vein

The information contained in this section is from Australian college of Phlebology and  www.patientinfo.co.uk.

NORMAL CIRCULATION

Healthy arteries and veins act as ‘one-way streets’, allowing blood to flow in one direction only. The beating heart directs blood through arteries to the entire body. Blood is then returned to the heart through the veins. The contraction of the leg muscles acts like a pump to move blood up the veins, against the force of gravity. The one-way valves in the leg veins prevent the backflow of blood down towards the feet.

There are two systems of veins: deep and superficial. Deep veins are located well below the skin, often within the muscles, and are crucial in maintaining a healthy circulation. Superficial veins are located near the skin surface, and drain into the deep veins through junctions. Superficial veins are also connected to deep veins through multiple small connections called ‘perforating veins’. Valves inside the perforating veins and junctions prevent the flow of blood back into the superficial veins. Blood thus naturally flows from the superficial veins into the perforating veins and junctions, which connect to the deep veins and then back to the heart.

Saphenous veins are the main superficial veins in the legs. Saphenous veins collect blood from other surface veins and drain it into the deep veins. The longest, the Great Saphenous Vein, is located in the inner aspect of the leg and travels from the ankle to the groin. The Small Saphenous Vein is located at the back of the calf muscle and travels from the outer ankle to the back of the knee. The Great Saphenous Vein is the vein that is most commonly ‘stripped’ in varicose vein operations.

 There are one-way valves at intervals inside the larger veins. These valves prevent blood flowing back in the wrong direction. When we stand there is quite a height of blood between the heart and legs. Gravity tends to pull the blood back down, but is prevented from doing so by the vein valves, and by the normal flow of blood towards the heart.

 

ABNORMAL VEINS

Abnormal veins have weak walls. These veins collect and contain more blood than normal veins, causing distension in the vein. Because of this distension, the valves no longer function properly, which causes a ‘leakage’, ‘reflux’ or ‘backflow’ in the affected vein. A vein demonstrating reflux is termed ‘incompetent’.

There are three types of abnormal veins, which are frequently seen in combination. ‘Spider veins’ (telangiectasias) are the fine red capillary veins. The larger blue veins are called ‘reticular veins’, and are slightly deeper below the skin’s surface. Varicose veins are the largest of the abnormal veins, and may bulge above the skin’s surface.

Backflow from larger veins into smaller capillaries causes their distension and the formation of so-called ‘spider veins’. This is why treatment of spider veins in the presence of an underlying varicose vein is not considered appropriate, because it does not address the underlying problem. Backflow also leads to congestion of blood in the leg veins, which can cause symptoms such as pain, fatigue, heaviness, aching, burning, throbbing, cramping and restless legs. Symptoms are often made worse by prolonged standing. The presence of a skin rash, small blue veins on the feet, skin discoloration and ulcers usually indicate advancing vein problems. Severe varicose veins can compromise the nutrition of the skin and lead to eczema, inflammation or even ulceration of the lower legs. Treating the abnormal veins will lead to improvement of the symptoms in the majority of patients.

Vein disorders are not always visible; diagnostic techniques are important tools in determining the cause, severity and extent of the problem. Apart from physical examination, non-invasive ultrasound is often used to assist with assessment of the veins. Ultrasound investigation can accurately measure vein diameter, assess reflux and contribute to a precise map of both normal and abnormal veins of the leg.