Compression therapy is basic treatment for chronic venous disease (CVD) of the lower limbs. Numerous studies have demonstrated the efficacy and safety of compression therapy in relieving symptoms such as pain, venous edema, leg heaviness and fatigue, as well as accelerating the healing of venous ulcers. It has been established that сompression therapy is indicated for patients with both minimally expressed manifestations of CVD and severe forms of the disease. At the same only one study has been conducted to assess the correction of venous outflow from the lower limbs and pelvis in patients with pelvic varicose vein (PVV) and pelvic congestion syndrome (PCS). However, the incidence of this pathology ranges from 15 to 30% in the female population. The cost to the healthcare system of treating these patients in the United States exceeds $2 billion. To date, the options and indications for compression therapy in patients with concomitant PVV and CVD have not been defined. The rational use of compression in this cohort of patients may contribute to the improvement of effective conservative treatment. In addition, inappropriate prescription of compression to patients with pelvic venous disease (which can be observed in real clinical practice) may discredit this simple, effective and safe therapeutic method. In addition, the research devoted to the problem of compression treatment of PVV will contribute to the development of new special compression products aimed at accelerating venous outflow from the pelvic organs. It can be assumed that this will serve as a stimulus for obtaining new data on the therapeutic effects of compression and create conditions for the creation of new technological directions in the production of compression knitwear.

This is a single-center, prospective, comparative cohort study. The duration of the study is from 4/5/2023 to 1/12/2023. The study will include 90 patients (40 patients with symptomatic PVV without CVD, 40 patients with asymptomatic PVV and symptoms of CVD, 10 patients with CVD of the lower limb without PVV.

Currently, the term "varicose veins" implies not only the pathology of the superficial veins of the lower limbs, but also the pelvic veins. As yet, no epidemiological studies have investigated the frequency of the combination of pelvic and lower limb varicose veins, but in some studies the authors point to a combination of lower limb varicose veins and pelvic varicose veins (PVV) in 30-60% of patients. In this scenario, we are discussing the disease's clinically manifested forms, where lower limb varicose veins are visually identified and pelvic veins are identified by ultrasound and manifest as symptoms of pelvic congestion syndrome. There is no evidence of a concomitant occurrence of asymptomatic or latent forms of varicose veins in the lower limbs and PVV. (In this cases during duplex ultrasound angioscanning (DUS), pathological blood reflux is detected in the dilated superficial veins of the lower limbs and pelvis. However, there are no symptoms or signs of the disease.) As a result, it is not possible to assess the true prevalence of the combination of CVD and PVV.

At the same time, it is evident that dilatation and reflux in pelvic veins cannot but affect the clinical course of CVD in general and lower limb varicose vein disease in particular. Multiple studies from our clinic and foreign colleagues have substantiated this claim. It is caused not only by anatomical links between pelvic veins and lower limbs (perineal, clitoral perforating veins, tributaries of internal iliac veins), but also by common triggering mechanisms and similar pathogenesis of lower limb varicose vein disease and PVV.

Considering the above, valid questions arise about the effect of pelvic varicose veins with reflux on lower extremity venous outflow:

1. How does asymptomatic pelvic vein dilation with reflux impact venous outflow from the lower extremities and the clinical manifestations of CVD?
2. Does symptomatic pelvic vein dilation with reflux affect venous outflow from the lower limbs and clinical manifestations of CVD?
3. Does vulvar vein dilation affect venous outflow from the lower limbs and CVD clinical manifestations?
4. Is the severity or exposure of pelvic congestion syndrome a predictor for the development of lower limb venous outflow disorders?
5. How does the severity of clinical manifestations of PCS correspond to the severity of hemodynamic disturbance, as determined through instrumental research methods?

These questions have significance not only in academic and scientific domains. They are directly related to the strategy and tactics of treating patients with a combination of varicose veins of lower limbs and PVV, PCS and CVD, since the following fundamental issues have not yet been resolved:

1. Do asymptomatic patients with instrumental detection of PVV and lower limb varicose vein require correction?
2. Is it appropriate to utilize compression knitwear in patients with an asymptomatic course of instrumentally confirmed venous outflow disorders with a combination of pelvic and lower extremity varicose veins?
3. Can the coefficient of pelvic venous congestion be utilized as a quantitative indicator to prescribe compression treatment for venous outflow disorders in the lower limbs of asymptomatic patients without signs of CVD? In other words, can the coefficient of pelvic venous congestion be used as a reference index for correcting the evacuative function of the tibial MVP in patients without clinical manifestations of CVD?
4. How effective is compression in correcting impaired venous outflow from the lower limbs in PVV patients? The severity of the clinical course of lower limb CPV is determined by objective symptoms such as pain, edema, trophic disorders, and venous ulceration. In patients with CVD, the severity of the disease course determines the development of pelvic congestion syndrome (PCS), which is manifested by chronic pelvic pain (CPP), hypogastric heaviness, and dyspareunia. CPP and dyspareunia are the main indicators of the severity of the clinical course of PCS. It has been demonstrated that PCS exacerbates the symptoms of CVD. Thus, correlating the severity of pelvic pain to the degree of pelvic venous fullness (coefficient calculated by pelvic venous scintigraphy) allows us to assume the presence of venous outflow disorders of the lower extremities. According to this hypothesis, the presence and severity of venous outflow disorders of the lower limbs can be determined not only by the results of instrumental examination of the pelvic and limb veins, but also by clinical assessment of the severity of CPP.

Inclusion Criteria:

• Patient age from 18 to 40 years;
• Presence of pelvic varicose veins according to DUS data;
• Reflux in the pelvic veins for more than 1 second before this DUS;
• Reflux in the superficial veins of the lower limbs.

Exclusion Criteria:

• Menopause;
• Pregnancy;
• Postthrombotic disease;
• Suspicion of May-Turner syndrome;
• Ultrasound signs of nutcracker syndrome

Patient age from 18 to 40 years and who regardless of their sex assigned at birth, identifies as a woman.

The study will consecutively include 90 female patients, including 80 patients with PVV and 10 patients without PVV. All patients will have a clinical examination and DUS of the veins of the pelvis and lower limbs, regardless of the presence or absence of clinical manifestations of diseases of the veins of the pelvis and lower limbs. Аll patients were performed radionuclide venography of the lower limbs and emission computed tomography (SPECT) of the pelvic veins with in vivo-labelled red blood cells (RBCs). Based on the results of radionuclide venography and SPECT, quantitative indicators of the work of the lower limbs MVP will be calculated (average transport time RPH) and Cpvc.