Objective: This study is a single-center prospective observational study, which recorded the pain scores of patients at four time nodes during surgery (puncture and catheterization, injection of swelling fluid, radiofrequency generator work, and end of surgery), and analyzed the correlation between intraoperative pain and age, gender, BMI and other factors, so as to summarize and improve the details of surgery and reduce patients' intraoperative pain.

Although the global vascular surgeons have made significant progress in the study of RFA in the treatment of VVs, there are still many unknown areas to be explored, and the current research mainly focuses on the surgical effect of RFA and related complications, while the research on intraoperative pain is relatively scarce. First of all, RFA does not have a clear definition of intraoperative pain in the treatment of varicose veins of the lower extremities, so it has not received enough attention in clinical practice, and many doctors regard the success of surgery as the end point of treatment, but ignore the impact of intraoperative pain on the patient's surgical experience. In addition, with the continuous progress of varicose vein surgery of the lower extremities, the anesthesia method has also changed from general anesthesia to combined spinal-epidural block to today's local anesthesia, the swollen anesthetic solution is the main anesthetic drug used in RFA surgery, and the infiltration of the swollen anesthetic fluid around the saphenous vein is the key to the success of RFA, but paradoxically, this is also the most intense part of the patient's pain, the swollen fluid is usually a crystalloid solution containing local anesthetic and epinephrine, which is acidic in nature, which is also the main reason for the "tingling" during skin infiltration , A Cochrane review noted that adjusting the pH of lidocaine solution by adding sodium bicarbonate significantly reduced the pain reported on a 10 cm visual analogue scale (VAS) during skin infiltration, and that the temperature of the swollen anesthetic solution also had an effect on pain during skin infiltration, Bell et al. and Alonso et al. In a prospective randomized controlled trial, it was found that heating the local anesthetic solution to 37°C and 42°C reduced pain sensation, and heating the local anesthetic solution containing epinephrine to near body temperature was effective in reducing the pain of local anesthetic infiltration in patients, however, in a randomized clinical trial in 2018, patients were divided into cold swollen fluid group (4 °C) and room temperature swollen fluid group (24 °C), and the authors found that patients in the cold swollen fluid group had less pain during and after RFA, The amount of postoperative analgesics was significantly reduced. Therefore, the patient's pain during RFA has become a problem that we must pay attention to, and the operator should pay attention to the details and pay attention to the patient's intraoperative condition during RFA, so as to reduce the patient's intraoperative pain and give the patient a better surgical experience.

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. radiofrequency 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;

Patients diagnosed with primary VVs from April 2023 to September 2023 who were admitted to the hospital and underwent RFA treatment for the main trunk of the saphenous vein