Lower extremity varicose vein surgery has a certain recurrence rate, with a preliminary nationwide recurrence rate of about 20%. In fact, a considerable number of recurrences of varicose veins in the lower extremities after surgery can be avoided. 1. The patient’s saphenous vein is not ligated. Many patients claim to have had saphenous vein stripping and a surgical scar in the groin area, but ultrasound shows that the saphenous vein is still present. This is often due to the surgeon’s clinical inexperience and ligating the branch as the main trunk. Or the saphenous vein cannot be found and the ligation is abandoned. Leaving the saphenous vein intact is the most common cause of recurrent varicose veins. 2.Sclerotherapy injection. Most domestic sclerotherapy injections for varicose veins are performed in small private medical institutions. Sclerosing only the varicose veins in the lower legs without dealing with the saphenous vein trunk leads to recurrence becoming almost inevitable with the potential for minor pulmonary embolism and a very significant obstacle to the implementation of surgery (only as an adjunctive treatment modality). 3, Poor closure or recanalization of the saphenous vein by laser or radiofrequency (caused by outdated surgical equipment or inexperienced surgeons). 4.Inadequate function of the small saphenous vein. The vast majority of doctors easily overlook the presence of lesions in the small saphenous vein during the first surgery. One is because the small saphenous vein is at the back of the calf; the other is because the small saphenous vein is located deeper and the dilatation is not easily detected. The reflux of the small saphenous vein can lead to the reappearance of the varicose vein. 5.Deep vein thrombotic disease. The increase of venous pressure in the case of deep vein discomfort leads to ineffective surgery. 6.Traffic vein insufficiency. For patients with severe deep venous reflux leading to traffic vein insufficiency, it is often accompanied by ulceration in the foot and shoe area. Some patients recur after surgery. 7.Segmental ligation. Vein branches are very rich, and the vein wall has strong anti-coagulation function. Segmental ligation without closing or stripping the vein often results in the varicose vein remaining due to blood filling (where the disadvantages of the traditional surgical approach lie). 8, Stenosis of the iliac vein, the left common iliac vein compression syndrome, which doctors call cokett syndrome or may-thurner syndrome, is an important finding in recent years. The iliac vein is deeply located and is disturbed by intestinal gas in front, so ultrasound should not detect the lesion. Stenosis of the iliac vein causes elevated venous pressure in the lower extremities, which manifests as valvular insufficiency. Therefore, when recurrent varicose veins are encountered clinically, the following can be done: first, ultrasound to check for residual saphenous vein, small saphenous vein insufficiency or the presence of traffic vein regurgitation. Secondly, to understand the patency of deep veins. Third, to understand the presence of stenosis in the iliac veins. The surgical approach is tailored to the cause of recurrence. If the main saphenous vein is left behind, the purpose can be achieved by using saphenous vein aspiration or closure. In cases of small saphenous vein insufficiency, stripping or closure of the small saphenous vein is done. In the case of the communicating vein reflux, endoscopic dissection of the communicating vein can be used. For iliac vein stenosis, interventional balloon dilation with stenting is used. Of course, the method that can best prevent recurrence of varicose veins after surgery is to advise the patient to seek treatment from a specialized and experienced vascular surgeon. This way, even if there is a recurrence after surgery, there is often only a localized varicose vein and it is easy to deal with. Early surgery is still necessary compared to the dangers of venous thrombosis, dermatitis, and ulcers that result from not having surgery.