OBJECTIVEThermoablation is increasingly being used as an alternative to traditional surgery for treating primary varicose veins. Electrocoagulation ablation (EA) of the Great Saphenous Vein (GSV) has demonstrated effectiveness and safety comparable to that of radiofrequency ablation (RFA); however, its long-term outcomes have not been previously investigated.METHODSThis study involves a long-term follow-up of patients who participated in a double-blind, randomized clinical trial. Individuals with lower limb varicose veins and incompetence of GSV were randomly assigned to two treatment groups: EA and RFA. Follow-up assessments were scheduled at 1 week, 3 months, 6 months, and annually thereafter. The primary outcome measured was GSV occlusion, evaluated through postoperative duplex ultrasound. Secondary outcomes included the complication rate and improvements in quality of life, assessed using the Aberdeen Varicose Vein Questionnaire (AVVQ) score.RESULTSA total of fifty-seven patients were included, which involved a cumulative 85 treated GSVs; 42 veins were treated with EA and 43 with RFA. At the 1-week, 3-month, and 6-month follow-ups, there were no statistically significant differences between the two groups regarding GSV occlusion rates (P=0.430; 0.157; 0.157, respectively), complication rates (P=0.717; 0.317; 0.320, respectively), or improvements in quality-of-life scores (P=0.540; 0.786; 0.401, respectively). After a median follow-up duration of 4.8 years (95% CI: 4.5-5.1 years), data for 59 procedures (69.4%) were available, showing occlusion rates of 89.7% for the EA group (N=29) and 66.7% for the RFA group (N=30) (P=0.001). There were no procedure-related complications (P=0.127), and no significant differences in the AVVQ scores (P=0.345) between the two groups analyzed.CONCLUSIONSEA has demonstrated effectiveness and safety for the ablation of the GSV, achieving a higher rate of venous occlusion compared to radiofrequency ablation (RFA) in the long-term follow-up. Additionally, the occurrence of complications and the impact on symptoms and quality of life were comparable between the two methods during long-term follow-up.