Varithena Versus Endothermal Ablation of the Great Saphenous Vein (VERITAS)

Inclusion Criteria: * Age ≥ 18 * Primary GSV incompetence, defined as reflux \> 0.5 seconds on Duplex ultrasound in a single limb (Note the contralateral limb can have varicosities or SVI if intervention is not required within 3 months i.e. asymptomatic) * Failed conservative therapy (compression, diet, exercise, leg elevation) * CEAP Clinical Condition Classification C2 - C6 * Vein diameter 5-10mm, inclusive * GSV treatable length \> 10cm * Superficial venous disease manifest by clinical symptoms (rVCSS ≥ 4) * Able to comprehend and sign an informed consent document and complete written study questionnaires * Willing and able to return for scheduled follow-up visits (7-days, 3-months, 6-months, 12-months, 24-months, and 36-months post-procedure) * Willingness to comply with post-treatment compression protocol Exclusion Criteria: * Allergy to polidocanol, xylocaine, or epinephrine * Deep vein thrombosis or pulmonary embolism within 3 months prior to randomization or hypercoagulable disorder * Post thrombotic deep vein disease above the calf veins * Pregnancy or lactating (within 30 days of randomization) * Symptomatic peripheral arterial disease or ankle-brachial pressure index (ABPI) \< 0.8 * Previous treatment to targeted incompetent GSV or previous superficial thrombophlebitis in targeted GSV * Previous venous intervention in affected limb in past 3 months * Local aneurysmal GSV segments * Inability to walk unaided * Inability to wear post-procedure compression bandaging and stockings * Patients with clinically significant reflux of the small saphenous vein (SSV) or anterior accessory saphenous vein (AASV) * In the clinical judgement of the investigator, patient who will require ipsilateral deep venous intervention within 3 months following randomized treatment * In the clinical judgement of the investigator, patient who will require contralateral venous intervention (superficial or deep) within 3 months following randomized treatment * Patient on therapeutic anticoagulants * Active malignancy * Life expectancy \< 2 years * Documented COVID-19 infection currently or within 2 months prior to randomization * Enrollment in another clinical trial that could confound the endpoint within 3 months prior to screening or within 3 months following enrollment