Open Label Safety Investigation of Solutio™ Tumescent Catheter

The goal of this clinical investigation is to evaluate safety of the Solutio™ catheter when administering tumescent anesthesia before treatment with endothermal ablation in adults above the age of 18, who suffer from unilateral insufficiency of the great saphenous vein (GSV). Main question(s) to answer is: Safety evaluated through reported Adverse Device Effects (ADEs) and Serious Adverse Device Effects (SADEs). Incidence of Adverse Events (AE), Adverse Device Effects (ADE), Serious Adverse Events (SAE), Serious Adverse Device Effects (SADE), and device deficiency (DD) throughout the investigation. All investigation participants will: * Undergo screening, including medical history, physical examination, and vein mapping with Doppler ultrasound. * Have their Great Saphenous Vein (GSV) treated using Seldinger technique under ultrasound guidance. * Receive tumescent anesthesia injected from inside the vein into the perivascular tissue at selected sites along the vein, using the investigational Solutio™ catheter under ultrasound guidance. * Undergo endothermal ablation, Endovenous Laser Ablation (EVLA), or Radiofrequency Ablation (RFA). * Be followed up for 28 days through scheduled phone calls (Day 1, Day 14 ±2) and clinic visits (Day 7 ±1, Day 28 ±2) to assess adverse events, pain, patient comfort, and undergo physical/clinical examinations and ultrasound examinations of the treated area.

Inclusion Criteria: 1. Male or Female \>18 years old. 2. Subject diagnosed with venous insufficiency in the Great Saphenous Vein from the groin to the proximal 1/3 of the lower leg and with a Clinical Etiological Anatomical Pathophysiological (CEAP) classification of 2 or higher. 3. Subject is scheduled for an EVLA or RFA procedure for a unilateral insufficiency of the GSV. 4. Subject accepts to be treated with endothermal ablation as a standalone method. 5. Subject accepts to be treated without any sedation. 6. Subject is willing and able to provide written informed consent. Exclusion Criteria: 1. Considered as being of high risk due to comorbidity in the opinion of the investigator. 2. Subject with known and confirmed coagulation defects. 3. Subject on anticoagulant treatment. 4. Subject who simultaneously needs to be treated with other supplemental techniques such as e.g., foam sclerotherapy, ligation, and phlebectomy. 5. Subject with GSV insufficiency in the distal 2/3 of the lower leg. 6. Subject, who demands full sedation, or general anesthesia. 7. Subject with known allergy to any of the tumescent and/or anesthetizing agents that will be used (per local standard practice) during the endothermal ablation procedure.