Chronic venous disease (CVD) is a widespread and challenging condition globally, encompassing the full range of anatomical and functional abnormalities in the venous system of the lower extremities. It is characterized by symptoms such as edema, skin changes, and venous ulcers, primarily caused by venous insufficiency with resulting reflux.

CVD significantly impacts quality of life and imposes a considerable socioeconomic burden. Lifestyle factors play a critical role in the risk of developing CVD. In recent years, average body mass index (BMI) values have risen in Western countries, with obesity recognized as a major risk factor for CVD. Additional factors, including smoking, physical inactivity, and hypertension, are also linked to an increased risk of CVD and chronic venous insufficiency.

There is a lack of recent Brazilian data on the prevalence and epidemiological characteristics of CVD, highlighting the need for this study. This research aims to gather national data on risk factors, associated comorbidities, and treatment types in Brazilian patients with CVD. The primary goal is to describe the clinical and epidemiological profile of CVD in the Brazilian population.

Chronic venous disease (CVD), also known as chronic venous insufficiency in its advanced stages, is marked by dysfunction in the peripheral venous system of the lower extremities, often due to venous flow obstruction or reflux. Affecting approximately 25-45% of women and 10-40% of men, CVD significantly increases public health expenditures. While the exact mechanisms remain unclear, evidence suggests that CVD is multifactorial, involving heightened inflammation, valvular incompetence, and calf muscle dysfunction, all contributing to impaired venous return and elevated venous pressure.

Common symptoms include varicose veins, lower limb edema, leg discomfort, and heaviness. CVD is progressive and can advance from superficial vessel involvement, known as telangiectasia, to deep venous ulcers. Risk factors such as family history, prolonged standing, smoking, and obesity can contribute to its onset and progression. Conservative management focuses on lifestyle changes like exercise, weight control, limb elevation, and compression. Pharmacologic or surgical intervention may be necessary in advanced cases. Left untreated, CVD can severely impact patients' quality of life, hindering daily and work activities.

However, data on CVD prevalence in Brazil is limited, largely based on a single study by Maffei et al. in 1986, which found a 47.6% prevalence of varicose veins and a 3.6% prevalence of advanced CVD in 1,755 adults in Botucatu, São Paulo. To better serve Brazilian patients, further data on CVD prevalence, treatment, and risk factors is essential, aiding healthcare providers in optimizing patient care.

This study aims to characterize the clinical and epidemiological profile of Brazilian CVD patients through a multicenter, prospective observational study. Conducted across 10 centers nationwide, the study will recruit at least 65 patients per center over 12 weeks.

Quality of life will be assessed using the Aberdeen Varicose Vein Questionnaire (AVVQ), with lower scores indicating better quality of life. The Venous Clinical Severity Score (VCSS) will gauge CVD severity, with higher scores indicating greater disease severity. VCSS correlates with the CEAP classification system and ultrasound findings.

CVD diagnoses will be categorized using the CEAP classification:

C0: No signs of venous disease C1: Telangiectasia/reticular veins C2: Varicose veins (≥3 mm diameter) C3: Edema C4: Skin/subcutaneous changes due to CVD, subdivided into C4a (pigmentation/eczema), C4b (lipodermatosclerosis/Atrophie Blanche), and C4c (corona phlebectatica) C5: Healed venous ulcer C6: Active venous ulcer C6r: Recurrent active venous ulcer During exams, patients will undergo physical evaluation for CVD signs, followed by duplex ultrasound of superficial and perforating veins. These will be conducted in both standing and supine positions by qualified vascular specialists, alongside personal medical history, demographics, occupation, physical stress, and varicose vein symptoms.

The study will measure factors including:

Presence and location of saphenous vein insufficiency, reflux, and vein caliber Presence of perforating veins and reflux characteristics Presence of deep vein thrombosis and related complications The study also covers therapeutic procedures such as sclerotherapy, endovenous ablation, and surgical vein removal. Compression stockings and pharmacological treatments (e.g., diosmin + hesperidin, calcium dobesilate, troxerutin) will be documented, including usage frequency and duration.

Data on cardiovascular diseases, comorbidities (e.g., hypertension, diabetes, dyslipidemia), occupation, and family history of CVD will also be collected, providing comprehensive insights into the risk and impact of CVD on the Brazilian population.

Inclusion Criteria:

• Patients of both sexes diagnosed with chronic venous disease;
• Age equal to or greater than 18 years;
• Signature of the informed consent form.

Exclusion Criteria:

• Non-agreement to participate in the study;
• Pregnant women.

Adult patients (≥ 18 years) diagnosed with chronic venous disease.