1. Data and methods 1.1 General data 20 patients were hospitalized, 6 men and 14 women, age 34-76 years, average 58.2 years; duration of disease 3-47 years, average 17.2 years. There were 8 cases of varicose veins in the left lower extremity, 4 cases in the right lower extremity and 8 cases in both lower extremities. Clinical manifestations: venous tortuosity and dilatation of lower limbs with soreness and heaviness, 18 limbs with pigmentation in the foot and shoe position. All the affected limbs were examined by ultrasound of the deep veins of the lower extremities before surgery, and all of them indicated the patency of the deep veins, 15 limbs indicated the incompetence of the deep vein valves, all cases marked the location of the root of the saphenous vein on the body surface, and the diameter of the saphenous vein did not exceed 2 cm.1.2 Surgical method Microwave intracavitary coagulation: lumbar anesthesia or epidural anesthesia was used. The saphenous vein trunk above the anterior part of the inner ankle is poked with a sharp knife for 1-2 mm, the trunk of the saphenous vein is separated and clamped with a mosquito-type vascular clamp, the incision is raised and then cut off, the distal end is ligated with a thin wire, the proximal end is inserted into the microwave radiator up to the root of the saphenous vein, the microwave treatment machine is turned on, the power is set at 70 w, 3-5 mm is used as a treatment point, the microwave pulse is foot-controlled, the microwave radiator is slowly withdrawn, and the treatment time is 2-3 seconds per point. The operator’s left hand presses the treatment point, the microwave work can feel the sense of subcutaneous vein contracture, and can hear the “silk” burning sound, the assistant compression has been treated parts, in order to fully close the vein. When the head of the radiator recedes to the knee area, the treatment is stopped and the radiator is pushed out. Switch to foam sclerotherapy. Preparation of foam sclerosing agent use: 10% polyglactin (China Shaanxi Tianyu Pharmaceutical Co., Ltd.) Take 2ml of the solution plus 8ml of air and mix it thoroughly to make 10ml of foam sclerosing agent, which is ready to use. The patient’s family should be asked to passively squeeze the gastrocnemius muscle group and observe whether the patient has any adverse reaction such as chest tightness, partly away from the main trunk of the varicose vein in the form of capsular cluster, use the scalp needle to inject more points, each point inject 2-3ml of foam sclerosing agent. The patient’s family was asked to passively squeeze the gastrocnemius muscle of the affected limb and do ankle flexion activities. The patients were asked to do ankle flexion activities after the resumption of voluntary movement, and to get out of bed after 6 hours. 3 days later, the bandage was lifted and the compression bandage was applied, and the patients wore long class II compression medical elastic stockings for 2 months. 2. Results No pulmonary embolism or acute lower limb deep vein thrombosis, no skin burns, no saphenous nerve injury, no numbness and tingling of the ankle skin, etc. occurred in all the cases after surgery. 15 limbs showed medial thigh striated swelling. The patients complained of local pulling sensation, 5 limbs had tolerable pain, which disappeared within 1-2 months, and 5 limbs had hyperpigmentation at the site of sclerotherapy injection, which faded away after 1-2 months. Three months after surgery, 23 limbs in 16 cases were reviewed by ultrasound of the deep veins of the lower extremities, which indicated that the deep veins of the lower extremities were open and the root of the saphenous vein was well closed, and there was no blood reflux. The patients’ soreness and heaviness disappeared, and no obvious superficial venous anger was seen.3. DiscussionThe varicose veins of lower limbs are common peripheral venous diseases. Surgery is a relatively radical treatment. In recent years, there is a trend to gradually replace traditional surgery because endovenous treatment is simple, minimally invasive and effective. Microwave endovenous coagulation for superficial varicose veins in the lower extremities utilizes the microwave effect on tissue thermal coagulation by applying microwave radiators directly to the vessel wall of the vein cavity, resulting in instantaneous (within seconds) coagulation of the tissue with a certain penetrating high temperature in a small area, followed by gradual fibrosis of the vessel cavity and eventual complete occlusion. Microwave coagulation heating is endogenous heating, its microwave tissue thermal coagulation effect compared with other energy heating methods, with high thermal efficiency, rapid heating, uniform tissue heating, moderate thermal penetration, short-term charring is not obvious, thermal coagulation range is easy to regulate, etc., after thermal coagulation is not easy to form mobile thrombus. Animal experiments have confirmed that cell degeneration and incomplete necrosis occur in 3 d after microwave coagulation; irreversible necrosis occurs in 7 d. Therefore, the possibility of postoperative vascular recanalization is extremely small, and the safety is high. Sclerotherapy was first proposed by Cassaigness in 1853, that is, chemical sclerosing agent is injected into varicose vein to cause secondary inflammatory reaction in the vein wall, and continuous postoperative compression causes the vein to atrophy, and granulation tissue then fibrosis grows in the lumen of the atrophied vein and eventually forms fibrous cords to treat varicose vein atrophy. Foam sclerotherapy is a new type of foam sclerosing substance formed by mixing liquid sclerosing agent with gas. Among many minimally invasive treatments for varicose veins in the lower limbs, foam sclerotherapy has a therapeutic effect on all kinds of varicose veins, and the literature has proved that it is safe, simple, economical, reliable and reproducible, and is used as a brand new method for treating varicose veins. In our group, 20 patients (24 limbs) were treated with endovenous microwave coagulation combined with polyglactin injection, and all superficial varicose veins disappeared after the procedure, and skin changes caused by varicose veins such as hyperpigmentation were significantly reduced. No serious complications such as pulmonary embolism and deep vein injury occurred, confirming that endovenous microwave coagulation combined with polyglaucine injection is a safe, minimally invasive, reliable and reproducible procedure.