Observation of Pain During the Treatment of Great Saphenous Vein Using Microwave Ablation， and Analysis of Related Factors

Inclusion Criteria: 1. Age≥ 18 years old, ≤ 90 years old; 2. the patient's life expectancy is greater than 12 months; 3. The clinical diagnosis is primary VVs, CEAP classification C2-C6, and the GSV segment needs to be treated, including pain, burning sensation, heaviness, fatigue, itchy skin, night cramps and other clinical symptoms; 4. Doppler ultrasound confirmed that the diameter of GSV was greater than 3mm and less than 12mm when standing; 5. Doppler ultrasound confirms that GSV is located in the saphenofascia or the distance between GSV and the skin surface is \>1cm; 6. endovenous microwave ablation treatment only for unilateral GSV walking area; 7. The patient is willing to cooperate with the completion of the examination specified in the protocol. Exclusion Criteria: 1. GSV thrombosis, or combined with deep vein thrombosis, or previous history of deep vein thrombosis and pulmonary embolism; 2. patients with recurrence after prior VVs-related surgery (C2r); 3. the GSV trunk is severely distorted, and it is expected that the catheter will not be able to pass; 4. Severe ischemia of the lower limbs, Ankle brachial pressure index (ABPI) \< 0.8; 5. Known allergy to the drugs and device materials involved in the study; 6. Previously implanted with a pacemaker or defibrillator, and currently receiving regular anticoagulation therapy (such as warfarin, heparin); 7. Pregnant or lactating females; 8. Patients who are unable or unwilling to participate in the study; 9. Participating in the research of other drugs or devices; 10. Skin malignancies other than non-melanoma that are being treated; 11. daily use of narcotic drugs or non-steroidal anti-inflammatory drugs to control pain caused by venous disease; 12. The investigator judged that endovenous treatment was not suitable;