Anatomy and physiology: The veins of the lower extremities are divided into superficial, deep and feeder veins. Superficial veins are located between the muscular fascia and the skin. The deep veins are wrapped by the deep fascia and travel within the muscle. Penetrating veins penetrate through anatomical levels. Because they are deep in the subcutaneous tissue, true saphenous veins are rarely seen in thighs with normal fat mass. Dilated, protruding and varicose veins are usually visible in the inner thighs and calves as saphenous varicose veins, and in most cases the varicose veins visible in the inner thighs and calves are branches of the saphenous vein. The most distinctive feature of the vein is the presence of a valve. The valves direct the flow of blood from the superficial and deep veins to the heart and are present in even the tiniest skin capillaries. Capillary dilation, spider veins, and varicose veins all lose valve function and have bidirectional mobility to the proximal and distal ends. Unlike deep veins, which are named according to their matching and accompanying arteries, superficial veins have no accompanying arteries; they are a series of subcutaneous veins that merge to form two major superficial veins, the greater and lesser saphenous veins. These veins drain into the deep veins at the saphenofemoral junction and the sapheno-N junction. The valves play an important role in transporting blood from the lower extremities back to the heart. As the valves close to allow upward flow of blood, and in order for the valves to close, there must be a reversal of the normal transvalvular pressure difference. Pathophysiological mechanisms: Insufficiency of the venous system is caused by injury to the venous wall and venous valves. The earliest manifestations are often superficial and dermal varicose veins. Deeper is the flattened blue-green reticular venous system. Eventually the deeper venous network itself becomes varicose. Skin pigmentation, scarring from previous ulcers, and active ulcers are collectively referred to as chronic venous insufficiency. Hypoxia, shear stress, and inflammatory cascade responses play a role in the development of venous insufficiency. Epidemiology: Body surface signs of venous insufficiency, varicose veins and capillary dilation are common. Epidemiological studies have shown that more than 20% of women and more than 10% of men have manifestations of venous insufficiency. The prevalence of varicose veins correlates only with gender and is more common in women. Even when large varicose veins are present, men younger than 60 years of age are often asymptomatic. In contrast, younger women are prone to characteristic symptoms including soreness, burning pain, itching, weakness and sinking of the lower extremities. Lesion characteristics: The geniculate branches of the saphenous vein are anatomically located on the subcutaneous, superficial surface of the superficial fascia with no other support. In contrast, the saphenous vein is located in the cavity of the saphenous vein between the deep and superficial fascia and is therefore strongly supported. The venous branches are located subcutaneously and are therefore more susceptible to damage in the presence of venous hypertension, which elongates and dilates them. Elongated and dilated venous branches and even dilated capillaries can compress the somatic nerves, causing the common symptoms of pain and dullness. Compression of the neurocutaneous branches produces the burning pain associated with venous neuropathy. Inflammation associated with varicose veins also occurs and can cause pruritus, which may develop into eczema-like dermatitis. Indications for intervention: 1. soreness; 2. heaviness in the legs; 3. leg fatigue; 4. superficial thrombophlebitis; 5. bleeding; 6. appearance. Treatment principles: 1. Basic treatment: compression with elastic bandage and elastic stocking. 2.Surgical treatment: complete removal of the saphenous vein from circulation has always been an important part of the treatment of primary venous insufficiency, and although saphenous vein stripping is no longer popular, this principle is still important today. Complications, trauma, pain and aesthetic impact are the main problems of this treatment. 3.Interventional treatment: The use of electromagnetic energy to destroy the vein in situ can avoid the trauma associated with saphenous vein stripping. The energy varies from radiofrequency waves to shorter wavelengths of laser waves. The energy is usually delivered through a catheter placed in the vein through a percutaneous puncture. The success rate of venous ablation is higher than 90% and is therefore considered to be the current standard of care.