Medically Fit For Exams
Medically Fit For Exams

Venous Thromboembolic Disease (VTE)


  • Formation of blood clots in the leg
  • As a result of abnormality to Virchow’s triad
  • Can result in DVT or PE


Risk factors

  • Virchow’s triad
    • Hypercoaguability
      • Cancer
      • Oral contraceptives
      • HRT
      • Anti-phospholipid syndrome
      • Pregnancy
      • Smoking
      • Obesity
    • Haemodynamic changes (stasis, turbulence)
      • Bed bound
      • Long-haul flights
      • Pregnancy
      • Atrial fibrillation
      • Surgery
      • Varicose veins
    • Endothelial damage
      • Hypertension
      • Chronic immune response
      • Trauma


Differential diagnoses

  • Peripheral arterial disease
  • Cellulitis
  • Baker’s cyst
  • Popliteal aneurism
  • Lymphedema
  • Peripheral oedema (from heart failure)
  • Haematoma
  • Muscle damage



  • VTE occurs at a rate of 1/1000 adults
  • Increased risk >45 y.o.
  • Slightly increased risk in men
  • 2/3 DVT 1/3 PE
  • Death within 1 month in 6% of DVT and 10% of PE





  • Clots forming in veins
  • Lodge in veins or venules in legs, or in the capillaries of the lungs
  • DVT: block up the vein, causing venous pooling
  • PE: blocks blood flow to the lungs, reduction in gaseous exchange – V/Q mismatch, may be a result of dislodged DVT


Clinical features

  • DVT
    • Swelling of the leg or along a vein in the leg (oedema)
    • Pain or tenderness in the leg (may only be felt upon standing or walking)
    • Increased warmth in the area of the leg that’s swollen or painful 
    • Red (erythema) or discoloured skin on the leg
    • Homan’s sign: pain on dorsiflexion (beware – may dislodge clot)
  • PE
    • Unexplained shortness of breath / rapid breathing
    • Pleuritic pain (with deep breathing)
    • Coughing up blood
    • Tachycardia



  • Thrombi may be formed from atherosclerotic plaques
    • The edges/shoulder of the plaques are at most risk of rupture
  • Thrombi may be formed spontaneously (virchow’s triad)



  • Wells score
    • Score including bedridden, swelling, tenderness, visible veins, other likely diagnoses, malignancy, previous DVT
  • D-Dimer blood test
    • Blood test, measures breakdown products of thrombus
    • High sensitivity but low specificity
    • Will appear raised for a number of reasons eg inflammation, pregnancy
    • So used to rule out PE/DVT in someone with low risk (97% certainty)
  • Duplex Doppler ultrasound
    • Doppler effect (change in pitch of sound waves) can be used to visualise flow/speed of blood
    • Attempt compression of vein – if can’t be compressed then DVT is diagnosed
    • Better at detecting above-knee DVT (95%) than below knee (60-70%)



  • Anti-coagulants
    • Heparin, warfarin, rivaroxaban
  • Thrombolytics
    • Tissue plasminogen activator/altepase
  • Inferior vena cava filters (DVT only)
    • Prevents pieces of clot dislodging and entering the heart or brain
  • Compression stockings (DVT only)
    • Prevent the oedema and venous pooling associated with DVT
    • May also be used as a prophylactic



  • Death within 1 month in 6% of DVT and 10% of PE
Venous thromboembolic disease.docx
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