Venous thromboembolism

Venous thromboembolism (VTE) is a condition that involves deep vein thrombosis (DVT) and pulmonary embolism (PE). It is estimated that approximately one in four deaths occur due to venous thromboembolism worldwide. It is a common, life-threatening disorder.

DVT involves the formation of blood clots (thrombus) in vein deep inside your body (most commonly in legs). A thrombus is composed of red blood cells, platelets and leukocytes bound together by fibrin. These clots either remain in the peripheral veins or embolize to the pulmonary arteries resulting in PE.

VTE is the third most prevalent cardiovascular disease (CV) after acute coronary syndrome and stroke. Nearly two-thirds of all VTE events result from hospitalization. PE is considered as third most common cause of hospital-related deaths.

Signs and symptoms

In some cases, VTE may not cause any symptoms and remains unnoticed. The signs and symptoms of VTE can be classified into two types based on location of the thrombi:

If you have deep venous thrombosis, you may experience:

  • Pain and tenderness in the affected leg
  • swelling and feeling of warmth in your leg

A limb-threatening manifestation of DVT that your doctor would identify includes massive limb swelling, high blood pressure in the capillary bed, and eventually ischemia and gangrene if left untreated. This is because the thrombus completely occludes venous outflow.

The signs and symptoms of pulmonary embolism include shortness of breath, tachypnea, chest pain, and dizziness.

Causes

VTE may occur as a result of genetic predisposition as well as acquired risk factors. Experts suggest that a major theory called Virchow's triad proposes that the condition is due to alterations in the blood flow, damage to your vessels walls, and increased activation of clotting factors.

Treatment

Treatment for VTE aims at preventing the growth of blood clot and formation of new clots. Prompt treatment is essential to avoid fatal complications.

Medications such as blood thinners also known as anticoagulants and clot dissolvers or thrombolytics are prescribed.

Surgical procedures such as clot removal are performed in the case of a very large, life-threatening clot in your lungs. Vein filters are used to prevent clots from being carried into your lungs. This procedure is typically used for those who are not suitable for anticoagulant drug therapy.

Complications

One of the major complications of VTE is its recurrence. The long-term complications of VTE include chronic thromboembolic pulmonary hypertension (CTPH) and the post-thrombotic syndrome (PTS).

Prevention or self- management

Following are certain measures to prevent VTE or recurrence of VTE:

  • Administer blood thinners or anticoagulants as prescribed
  • Wear compression stockings
  • Place your legs in the elevated position
  • Perform regular physical activity
  • Perform pneumatic compression (as per your physical therapist instructions)
  • Avoid sitting for prolonged periods
  • Maintain a healthy weight
  • Quit smoking

The common risk factors for VTE include:

  • Acute medical illness leading to hospitalization
  • Infection
  • Age >760
  • Family history of VTE
  • Cardiovascular diseases, such as hypertension
  • Diabetes mellitus and high cholesterol levels
  • History of smoking
  • Genetic risk factors (factor V Leiden, protein C and S deficiency, prothrombin gene mutation G20210A, and anti-thrombin deficiency)
  • Use of birth control pills
  • Being overweight or obese
  • Sitting for prolonged periods
  • Prolonged bed rests in conditions such as paralysis
  • Cancer

Your doctor begins the diagnosis with a thorough physical examination that includes checking for the signs and symptoms of VTE. The common diagnostic tests to identify VTE include:

  • Blood tests: Your blood sample is tested to determine the levels of D-dimer, a clot-dissolving substance. Also, your blood is tested for bio-markers, such as troponin and brain natriuretic peptide to identify right ventricular dysfunction (one of the causes of PE).
  • Doppler ultrasonography: The test is used to obtain a detailed view of the clot.
  • Venography: During the test, a dye is injected into your vein present in the foot or ankle. Simultaneously, X-rays were taken to identify the clots.
  • Imaging studies: Computerized tomography and magnetic resonance imaging provides a detailed view of your veins and identifies the clot.
  • Tests to identify PE are chest X-ray, arterial blood gas determination, pulmonary angiography, and ventilation-perfusion scanning.