Deep vein thrombosis: venography had side effects and may not be possible.

Clinical bottom line (level 4)

  1. Around a fifth of patients with suspected deep vein thrombosis who had a venogram had side effects- mostly pain. Serious side effects were rare.
  2. 5% of venograms were not technically possible.
  3. Venography may possibly cause DVT.
Lensing et al: Radiology 1990; 177: 503-505
Expires September 2003

The study

Prospective cohort study with unblinded, unobjective outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: university hospital, Italy

463 patients (aged range 17 to 89 years; mean 58, 54% female) suspected deep vein thrombosis

Excluded if
  • contrast media allergy
  • renal insufficiency
  • obvious local infection of foot


    • All patients had contrast venography using 150 ml of low-osmolar contrast media (iohexol), followed by 250 ml saline flush. 41 patients with negative venograms and not anticoagulated, and without signs of infection or inflammation, had I-125 fibrinogen scans on day 1, 2, 4 and 6. if any scan was positive, a repeat venogram was performed.

    100% followed for one week
    Outcomes studied:
  • minor side effects local pain and discomfort, nausea, dizziness, skin reaction, oedema, superficial phlebitis
  • serious side effects cardiovascular collapse, angioneurotic oedema, bronchospasm
  • DVT from venogram
  • any venous thromboembolism from venogram

    • Technicians completed questionnaires about side effects. The questionnaire was repeated after one week in outpatient.

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    minor side effects one week 83/463 18%
    (14% to 21%)
    serious side effects one week 2/463 0.4%
    (0.0% to 1.0%)
    DVT from venogram one week 0/463 0.0%
    (0.0% to 0.6%)
    any venous thromboembolism from venogram one week 1/463 0.2%
    (0.0% to 0.64%)

    • Minor side effects: 67% with pain in foot or calf; 25% with nausea; 8% with dizziness; 6% with skin reactions.
    • Serious side effects: both bronchospasm.
    • Venous thromboembolism: one clot in lesser saphenous vein.
    • 5.3% of patients were unable to have venography (due to technical difficulties).

    Comments

    1. I-125 fibrinogen scans have poor sensitivity- some DVTs may have been missed.

    Citation

    1. Lensing AWA, Prandoni P, Buller HR, et al: Lower extremity venography with iohexol: results and complications.. Radiology 1990; 177: 503-505
    Contributor: Chris Ball and Clare Wotton, May 2000
    Reviewer:

    Clinical Question.
    Patient suspected DVT
    Intervention or Exposure venography
    Outcome side effects