A single-center, open, prospective, randomized, controlled clinical trial will include 120 patients with lower limb lymphedema who undergo treatment in an office-based vascular lab at the Ryazan regional clinical cardiology dispensary, Ryazan, Russia. The patients will be recruited by the staff of the Department of cardiovascular, endovascular, operative surgery, and topographic anatomy, Ryazan state I.P. Pavlov medical university, Russia. The study will include patients who meet the inclusion criteria and do not meet the exclusion criteria. Patients will be divided into 4 groups, 30 subjects each. Group 1-patients with lower limb lymphedema who will receive conservative therapy with elastic compression and an antioxidant (Tocopherol-400 IU/day); Group 2-patients with lower limb lymphedema who will receive conservative therapy with Micronised purified flavonoid fraction (diosmin+flavonoids expressed as hesperidin)-1000mg/day) in addition to elastic compression; Group 3-patients with lower limb lymphedema who will be treated with elastic compression; Group 4- healthy volunteers with no history or clinical signs of venous or lymphatic disease; The duration of this study for each subject will be a maximum of 90 days. Pre-screening and screening will involve 200 subjects with a total of 120 subjects who will be randomized into the study. Peripheral blood samples will be collected to evaluate the activity of biochemical markers of endothelial function; the quality of life will also be assessed.

Research methods:

1. Physical examination;
2. peripheral blood sampling (assessment of the concentration of the markers of endothelial dysfunction, including malondialdehyde (MDA), superoxide dismutase (SD), catalase( CAT), glutathione peroxidase (GP). MDA concentration will be determined with a competitive enzyme immunoassay (ELISA), which will be performed using a General MDA assessment kit (manufacturer: USCN Life Science Inc. US-CEA597GE). CAT concentration will be determined using a competitive enzyme immunoassay (ELISA), which will be performed with a kit for quantitative in vitro assessment of catalase (manufacturer: USCN Life Science Inc. US-SEC418Hu). GP concentration will be determined with a competitive enzyme immunoassay (ELISA), which will be performed using a glutathione peroxidase quantification set (abfrontier supplier, Republic of Korea - LF- EK0110). SOD concentration will be determined using a competitive enzyme immunoassay (ELISA), which will be performed using a total superoxide dismutase detection kit (supplier Cayman Chemical Company, US - 706002).
3. Lower limb venous sonography with a linear 5-13 MHz probe;
4. Patient questionnaire using a Russian-language version of the Quality of life questionnaire "SF-36 Health Status Survey"

Inclusion Criteria:

• Secondary lymphedema of the lower extremities
• Signed Informed Consent Form

Exclusion Criteria:

• varicose veins of the lower extremities,
• deep vein thrombosis,
• post-thrombotic disease,
• obliterating
• atherosclerosis of the lower limb arteries,
• pregnancy,
• lactation,
• cancer,
• acute violation of cerebral circulation in the anamnesis,
• trophic lesions of the skin of the lower extremities,
• diabetes mellitus
• an infectious disease with a history of three months prior to inclusion in the study,
• heart failure,
• kidney failure,
• pulmonary insufficiency.