Skip to Main Content

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

  • Lower leg pain, swelling, erythema

  • Palpable cord, especially in the calf

  • Duplex ultrasound evidence of thrombus

  • Evidence of thrombus on CT or magnetic resonance angiography

GENERAL CONSIDERATIONS

  • There are 3 basic mechanisms of venous thrombus formation (Virchow’s triad):

    • – Venous stasis

    • – Vessel wall damage

    • – Hypercoagulability

  • Venous stasis is usually caused by:

    • – Extrinsic compression from adenopathy or tumors

    • – Intrinsic fibrosis or venous extension of tumors

    • – Also can be caused by low-flow states, such as heart failure

  • Endothelial damage, such as during limb surgery, exposes blood to the vessel media that contains tissue factors that initiate the cascade leading to blood clotting

  • Hypercoagulability can be genetic or acquired

    • – Genetic examples are deficiencies in factors V Leiden and protein C or S

    • – Acquired examples are estrogen therapy and antiphospholipid antibody syndrome

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

  • Pain and swelling in an extremity, usually a lower leg

  • Bilateral swelling less likely thrombotic in origin

PHYSICAL EXAM FINDINGS

  • Pitting edema

  • Tenderness to palpation along the deep vein distribution

  • Homan’s sign (pain on dorsiflexion of the foot) is uncommon

  • A palpable venous cord is unusual unless there is also superficial venous involvement

  • Phlegmasia cerulea dolens is rare (ie, severe pain and swelling accompanied by cyanosis [tissue ischemia])

DIFFERENTIAL DIAGNOSIS

  • Ruptured Baker’s cyst

  • Abscesses

  • Ruptured plantaris tendon

  • Muscle strain

  • Tumors

DIAGNOSTIC SCHEMA: WELLS RULE

  • One point for each of the following:

    • – Cancer

    • – Leg immobilization

    • – Patient immobilization: > 3 days; surgery < 4 weeks ago

    • – Tender deep vein palpation

    • – Swollen leg

    • – Calf circumference difference > 3 mm

    • – History of deep vein thrombosis (DVT)

  • Alternative diagnosis (see Differential Diagnosis above) more likely (subtract 2 points)

  • DVT diagnosis likely ≤ 1 point; DVT likely > 1 point

DIAGNOSTIC EVALUATION

LABORATORY TESTS

  • D-dimer (thrombin breakdown products) positivity is nonspecific, but a negative test is very specific. It is generally safe to withhold anticoagulant treatment without further diagnostic testing if the D-dimer is negative and the Wells Rule score is ≤ 1

  • Factors II, VIII, and V Leiden; proteins S and C; antithrombin III; anticardiolipin antibodies, and homocysteine levels

ELECTROCARDIOGRAPHY

  • Could show right ventricular hypertrophy if pulmonary emboli are present

IMAGING STUDIES

  • Duplex ultrasonography can identify thrombus in veins

  • MRI is useful for distinguishing new from old thrombi

  • CT scan of the leg is becoming more widely used in conjunction with CT scans of the chest for pulmonary emboli

DIAGNOSTIC PROCEDURES

  • Contrast venography

TREATMENT

CARDIOLOGY REFERRAL

  • Suspected ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.