Deep vein thrombosis of lower extremities: general information

Deep vein thrombosis of the lower extremities [deep venous thrombosis (GVT) occurs when blood is clotted in the deep veins of the extremity (usually the lower leg or thigh)] or pelvis. Deep vein thrombosis of the lower extremities is the main cause of pulmonary embolism. Deep vein thrombosis of the lower extremities develops at conditions that worsen venous return, lead to damage to the endothelium and its dysfunction.

Deep vein thrombosis of the lower extremities can develop in the deep veins of the upper extremities (4-13% of cases of deep venous thrombosis), lower extremities or pelvis .. Deep vein thrombosis of the lower extremities is much more likely to cause pulmonary embolism (PE), perhaps because of greater massiveness a thrombus. The superficial femoral and popliteal veins on the hip, as well as the posterior tibial vein on the lower leg, suffer most often. Deep vein thrombosis of the lower leg veins is less likely to become the source of a large embolus, but can cause the recurrence of small emboli or spread to the proximal veins of the thigh and then lead to pulmonary embolism. Approximately 50% of patients with deep venous thrombosis have asymptomatic pulmonary embolism, and approximately 20% of patients with pulmonary embolism are diagnosed with deep vein thrombosis of the lower extremities.

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Causes of deep vein thrombosis of lower extremities

Many factors can contribute to deep vein thrombosis of the lower extremities. Deep vein thrombosis of the lower limbs is most often the result of reduced venous return (for example, in immobilized patients), endothelial damage, impaired function (for example, after fractures of the leg) or hypercoagulation.

What causes thrombosis of the deep veins of the lower extremities?

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Symptoms of deep vein thrombosis of lower extremities

Most deep venous thrombi occur in small veins of the lower leg, they are asymptomatic. When symptoms appear (for example, indeterminate aching pain, tenderness along the veins, edema, erythema), they are nonspecific, vary in frequency and severity and are the same in the hands and feet. Perhaps a visible or palpable widening of the collateral surface veins. Discomfort in the lower legs, when bending the leg in the ankle joint with a straightened knee (Homens symptom), is sometimes found in deep venous thrombosis of the distal segments of the foot, but it does not have sensitivity and specificity.

Deep Vein Thrombosis of the Lower Extremities: Symptoms

Diagnosis of deep vein thrombosis of lower extremities

Anamnesis and physical examination help to identify the likelihood of deep venous thrombosis before the research. The diagnosis is confirmed by Doppler ultrasonography with flow investigation (duplex ultrasonography). The need for additional studies (for example, the study of the content of D-dimer), their choice and consistency depends on the results of ultrasound. No existing research protocol is recognized as the best.

Deep vein thrombosis of the lower extremities: Diagnosis

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Treatment of deep vein thrombosis of lower extremities

Treatment is directed primarily to the prevention of pulmonary embolism, and secondly - to reduce symptoms, prevent chronic venous insufficiency and post-phlebitis syndrome. Treatment of deep venous thrombosis of the lower and upper extremities is generally the same.

All patients are prescribed anticoagulants, first an injectable preparation of heparin (unfractionated or low molecular weight), then warfarin (in the first 24-48 hours). Inadequate anticoagulant therapy in the first 24 hours may increase the risk of pulmonary embolism. Acute deep venous thrombosis can be treated on an outpatient basis if there is no suspicion of pulmonary embolism, severe symptoms (in this case, parenteral analgesics are indicated), other nuances that interfere with safe outpatient treatment, and certain specific factors (eg, impaired function, socio- economic aspect).

Deep vein thrombosis of lower extremities: Treatment

Prevention of deep vein thrombosis of lower extremities

Patients with a low risk of deep venous thrombosis (eg who underwent a minor surgical intervention but who have no clinical risk factors for deep venous thrombosis, as well as those who need to be temporarily restricted in movements for a long period, such as during an air flight) must walk or periodically perform various moves with your feet. Apparently, it's enough to bend your legs 10 times an hour. There is no need for treatment.

How to prevent deep vein thrombosis of the lower extremities?

Prognosis of deep vein thrombosis of lower extremities

Without the necessary treatment for deep venous thrombosis, the lower extremity has a 3% risk of fatal pulmonary embolism. Death due to deep venous thrombosis of the upper limb is very rare. The risk of repeated deep venous thrombosis is lowest in patients with transient risk factors (eg, surgical intervention, trauma, temporary immobility) and is greatest in the presence of persistent risk factors (eg, heart failure, malignant neoplasms), idiopathic deep venous thrombosis or incomplete resolution of the past deep venous thrombosis (residual thrombus). D-dimer content <250 ng / ml after discontinuation of warfarin can help predict a relatively low risk of recurrence of deep venous thrombosis or pulmonary embolism. The risk of venous insufficiency can not be predicted. Risk factors for post-phlebitis syndrome include proximal thrombosis, repeated deep venous thrombosis on the one hand, overweight (BMI 22-30 kg / m) and obesity (BMI> 30 kg / m).