This study aims to systematically compare the clinical efficacy (venous closure rate and symptom relief rate), safety (perioperative and postoperative complications), and cost-effectiveness (direct medical costs) of domestic Xianruida radiofrequency catheter and imported Medtronic catheter in endovenous radiofrequency ablation for varicose veins through a single-center, prospective, non-inferiority randomized controlled trial.

Background and Rationale：Varicose veins of the lower extremities are a common vascular disorder, affecting approximately 30% of the adult population globally. In China, the number of patients with varicose veins exceeds 120 million, with a higher prevalence in females (66.7%) and a trend towards younger age groups. Traditional treatment methods, such as saphenofemoral ligation and vein stripping, as well as sclerotherapy, are associated with significant trauma and a higher risk of complications, including nerve damage and thrombosis formation. In contrast, radiofrequency ablation (RFA) has emerged as a minimally invasive, effective, and safe treatment option, with a faster recovery time and fewer complications. RFA is now recommended as a first-line treatment in international guidelines.

Despite the advantages of RFA, its adoption in China remains low, with a penetration rate of less than 5%, compared to over 30% in European and American countries. The primary barriers to wider adoption include the high cost of imported equipment (with brands like Medtronic dominating over 90% of the market) and insufficient technical dissemination in grassroots hospitals. In 2022, Xianruida's venous endovenous radiofrequency ablation system was approved for market, marking the first domestic radiofrequency catheter system with independent intellectual property rights. This system features advanced technologies such as an adaptive PID temperature control algorithm, dual-system monitoring, and optimized heating curves, enabling faster heating times (20% shorter than imported devices) and more stable temperature control (fluctuation range of ±1℃), thereby reducing the risk of thermal injury.

Study Objective：The primary objective of this study is to systematically compare the clinical efficacy, safety, and cost-effectiveness of domestic Xianruida radiofrequency catheters and imported Medtronic catheters in the treatment of varicose veins using a single-center, prospective, non-inferiority randomized controlled trial (RCT). Specifically, we aim to verify whether the domestic catheter is non-inferior to the imported product in terms of therapeutic effect and whether it offers significant economic advantages. This will provide comprehensive and scientific evidence for clinical decision-making, optimize treatment strategies for varicose veins, enhance the utilization efficiency of medical resources, and improve patient outcomes.

Study Design and Methodology This study is designed as a single-center, prospective, non-inferiority, randomized controlled trial（RCT）, following the CONSORT statement. The non-inferiority margin for the primary endpoint (venous closure rate at 12 months postoperatively) is set at Δ≤10%, based on international guidelines and similar studies.

Sample Size and Calculation: The sample size is estimated based on the literature and clinical practice. Assuming a postoperative venous closure rate of 95% in the control group (Medtronic catheter), and expecting similar closure rates in the experimental group (Xianruida catheter), with a non-inferiority margin of 10%, a significance level (α) of 0.05 (two-sided), and a power (1-β) of 0.8, the required sample size is 92 patients per group. Considering a 20% dropout rate, a total of 200 patients (100 in each group) will be recruited.

Randomization and Blinding: Patients will be randomly assigned to either the experimental group (Xianruida catheter) or the control group (Medtronic catheter) using a computer-generated block random sequence (block size=4) with central randomization by an independent third party. The study will employ assessor-blinding (ultrasound physicians and follow-up nurses) and patient-blinding. Due to the nature of the procedure and differences in catheter appearance, surgeons will not be blinded, but standardized surgical procedures and training will minimize bias.

Intervention and Postoperative Management： Surgical Procedure: Both groups will undergo standardized RFA (great saphenous vein/small saphenous vein closure) performed by the same surgical team. Catheter parameters will be set according to the manufacturer's instructions (temperature 120℃, withdrawal speed 1cm/min).

Postoperative Management: All patients will receive uniform compression dressing (elastic bandage + Class II compression stockings), oral anticoagulant medication, and painkillers as needed based on the patient's condition.

Outcome Measures Primary Endpoint: Venous closure rate confirmed by ultrasound at 12 months postoperatively (complete closure: no blood flow signal; partial closure: blood flow signal <10cm).

Secondary Endpoints:

Clinical Effectiveness: VCSS score (venous clinical severity score), AVVQ score (venous disease quality of life score), and CIVIQ-20 quality of life scale at 3, 6, and 12 months postoperatively.

Safety: Intraoperative complications (vascular perforation, catheter failure), postoperative complications (pain VAS score, DVT, skin burns, swelling, numbness, and skin sensation abnormalities), and use of anticoagulant and pain medications.

Cost-Effectiveness: Direct medical costs (catheter cost + surgical consumables + hospitalization costs) and indirect social costs (time to resume normal life).

Inclusion Criteria:

1. Age between 18 and 80 years old.
2. Clinically diagnosed with primary lower extremity varicose veins, with CEAP grade C2 - C5, and requiring treatment of the great saphenous vein segment.
3. Doppler ultrasound confirms that the reflux time of the saphenofemoral vein valve is > 1.0 second.
4. Doppler ultrasound confirms that the diameter of the great saphenous vein in the supine position is > 3mm and < 12mm.
5. Only one limb of each patient is included in the study.
6. The patient signs the informed consent form and is willing to cooperate with the examinations and follow - ups specified in the protocol.

Exclusion Criteria:

1. Thrombosis in the great saphenous vein, or combined with deep vein thrombosis, or a history of deep vein thrombosis or pulmonary embolism.
2. Recurrent varicose veins after previous treatment.
3. Severe tortuosity of the great saphenous vein, with the expectation that the catheter cannot pass through.
4. Severe lower extremity ischemia (CLI).
5. Known allergy to drugs or device materials involved in the study.
6. History of cardiac pacemaker or defibrillator implantation.
7. Pregnant or breastfeeding women.
8. Currently participating in other drug or device studies.
9. Deemed unsuitable for endovenous treatment by the researcher.