Deep vein thrombosis
Deep vein thrombosis (DVT) is the formation of a clot inside the deep veins, almost always in the legs. It is a serious condition requiring rapid diagnosis and treatment, because the clot can break off and travel to the lungs (pulmonary embolism).
If one leg suddenly becomes swollen and painful, or you feel short of breath with chest pain, go to A&E or call 112.
Symptoms
- Swelling of one leg, developing quickly.
- Pain or tightness in the calf or thigh, which increases when walking.
- Warmth and redness or purplish discolouration of the skin.
- More prominent surface veins.
Sometimes thrombosis causes few symptoms and the first sign is a pulmonary embolism: sudden shortness of breath, chest pain on breathing, palpitations or coughing up blood.
Risk factors
- Immobility: hospital admission, recent surgery (especially hip or knee), plaster casts or long journeys, including long-haul flights.
- Cancer and its treatments.
- Pregnancy, the postpartum period, hormonal contraception and hormone therapy.
- Personal or family history of thrombosis and thrombophilias.
- Older age, obesity and some inflammatory diseases.
- Anatomical compression of the iliac vein (May-Thurner syndrome).
How it is diagnosed
Clinical assessment (probability scores such as the Wells score) is combined with a blood D-dimer test and, above all, venous duplex ultrasound, which confirms the clot by compressing the vein with the probe. It is quick, painless and uses no radiation.
Treatment
The mainstay is anticoagulation, which stops the clot from growing and reduces the risk of embolism and further thrombosis. The European guidelines (ESVS 2021) recommend:
- Starting anticoagulation as soon as the diagnosis is confirmed.
- Preferring direct oral anticoagulants in most patients, except in specific situations.
- Continuing it for at least 3 months; afterwards, whether to extend it is decided according to the cause of the thrombosis and the bleeding risk.
- Walking from the start: bed rest is not indicated.
In extensive thrombosis of the iliac or femoral vein, in selected cases, endovascular techniques may be considered to remove the clot or treat a compression of the vein.
After-effects: post-thrombotic syndrome
Between 20% and 50% of patients with DVT eventually develop post-thrombotic syndrome: heaviness, swelling, pain and, in severe cases, skin changes and ulcers, because of the damage the clot leaves on the valves. That is why follow-up matters: assessing recanalisation of the vein with duplex ultrasound and treating the symptoms. Compression stockings relieve swelling, although a large trial (SOX) did not show that they routinely prevent post-thrombotic syndrome.
Follow-up in clinic
- Clinical and ultrasound monitoring of progress.
- Thrombophilia testing and referral to haematology when indicated.
- Decision on the duration of anticoagulation.
- Treatment of venous after-effects.
Videos on this topic (in Spanish)
References
- Kakkos SK, Gohel M, Baekgaard N, et al. European Society for Vascular Surgery (ESVS) 2021 Clinical Practice Guidelines on the Management of Venous Thrombosis. Eur J Vasc Endovasc Surg. 2021;61(1):9-82.
- Kahn SR, Comerota AJ, Cushman M, et al. The postthrombotic syndrome: evidence-based prevention, diagnosis, and treatment strategies. A scientific statement from the American Heart Association. Circulation. 2014;130(18):1636-1661.
- Kahn SR, Shapiro S, Wells PS, et al. Compression stockings to prevent post-thrombotic syndrome: a randomised placebo-controlled trial (SOX). Lancet. 2014;383(9920):880-888.
Patient information reviewed by Dr Óscar Merino, vascular surgeon. It does not replace an individual medical assessment.
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Consultation with duplex ultrasound at Clínica Rotger, in the centre of Palma.
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