Introduction: Lower extremity Chronic Venous Insufficiency is a prevalent disease that adversely affects an individual's Quality of Life. Varicose vein endovenous radiofrequency treatment have a lower risk of iatrogenic injuries and offer faster return to work activities, when compared with open surgical techniques. Endovenous electrocoagulation can selectively and safely cause Great Saphenous Vein (GSV) wall necrosis but its clinical results has never been studied before.

Objective: The objective of this study is to compare Great Saphenous Vein electrocoagulation and radio frequency (RF) endovascular varicose vein treatment clinical results and quality of life improvement in a prospective double blind randomized controlled clinical trial.

Methods: Consecutive patients with varicose veins and primary GSV reflux will be randomized to Electrocoagulation or Radiofrequency endovenous treatment. The primary outcome measure will be GSV occlusion rate at 3 and 6 months after treatment verified by Duplex Scanning (DS). Secondary outcome measures will be pain visual analogue scale (VAS), bruising, neuropathy and vein thrombosis frequency in the immediate postoperative period (1 week); and Clinical Etiology Anatomy and Pathophysiology (CEAP) classification ,Venous Clinical Severity Scale (VCSS), and Aberdeen Varicose Vein Questionnaire (AVVQ), obtained preoperatively, at 3 and 6 months postoperatively. For statistical analysis, we will use the Student's t test, the Mann-Whitney test and Pearson's correlation, considering positive statistical significance when level of p <0.05.

All patients included in the study will be preoperatively examined to evaluate the severity of venous disease, using the CEAP classification, VCSS and AVVQ. They will undergo venous DS with the aim of investigating GSV insufficiency, its caliber and depth and presence of previous thrombophlebitis.

Patients will be randomized on the day of surgery with an electronic table of random numbers:

Group 1:Electrocoagulation treatment. Group 2: Radiofrequency treatment.

Patients and outcomes assessor will be blinded to the group of endovenous treatment.

Inclusion Criteria:

• Symptomatic varicose veins of the lower limbs and partial or total failure (venous reflux) of the GSV

Exclusion Criteria:

• Previous varicose vein surgery with removal of the GSV
• Pregnant women
• Patients in use of anticoagulants
• Known thrombophilia
• Presence of saphenous vein tortuosity and/or depth less then 7 mm from the skin
• GSV diameter < 5mm and > 12 mm
• Previous deep vein thrombosis
• Peripheral arterial disease.