Deep vein thrombosis

Deep vein thrombosis (DVT) is a medical condition involving the formation of a blood clot in a deep vein, most commonly in the legs. It can lead to serious complications, such as pulmonary embolism (PE) and post-thrombotic syndrome.

Signs and Symptoms

DVT predominantly affects the legs and manifests over hours to days. Symptoms include pain, swelling, redness, and enlarged veins in the affected limb. However, some cases may be asymptomatic. Other signs include tenderness, pitting oedema, warmth, and discolouration. Severe cases can show cyanosis and fever. In rare instances, DVT can cause symptoms in both limbs.

Complications

The most significant complication of DVT is PE, occurring when a clot detaches and travels to the lungs, causing sudden shortness of breath, chest pain, and possibly hemoptysis. PE can be fatal in up to one-fourth of cases. Phlegmasia cerulea dolens is a severe complication characterised by extensive clot formation leading to limb swelling and cyanosis, and may result in venous gangrene.

Diagnosis

Diagnosis involves clinical assessment using tools like the Wells score, which categorises DVT likelihood. A D-dimer test helps exclude or indicate the need for further testing. Ultrasound is the primary imaging method for confirming DVT. Other imaging techniques include CT and MRI venography.

Treatment

Anticoagulation is the standard treatment. First-line oral anticoagulants include rivaroxaban and apixaban. Warfarin is used with initial parenteral anticoagulants like heparin. The duration of therapy varies from 4-6 weeks to indefinite, based on the risk of recurrence and provocation status.

For severe cases like phlegmasia cerulea dolens, catheter-directed thrombolysis and mechanical thrombectomy are options. Inferior vena cava (IVC) filters are used when anticoagulation is contraindicated.

Prevention

Preventive measures include maintaining an active lifestyle, frequent walking, and avoiding obesity. Hospitalised patients may receive anticoagulants, and post-surgery patients may use mechanical devices like intermittent pneumatic compression. Pregnant women are often advised against warfarin due to birth defect risks and are monitored closely.

Epidemiology

DVT is more common with age, and the risk is higher in hospitalised patients, those with cancer, and post-surgery patients. It is also noteworthy that certain ethnicities have a lower risk of VTE compared to White or Black populations.

Social Impact

DVT can significantly affect lifestyle, particularly for individuals on blood thinners who must avoid activities that increase bleeding risk. Notable individuals such as Serena Williams and Chris Bosh have publicly shared their experiences with DVT, highlighting the condition's impact.

Historical Context

The understanding of DVT has evolved significantly since the first descriptions in ancient texts. Rudolf Virchow's 1856 work laid the foundation for the modern understanding of DVT, emphasising the roles of stasis, hypercoagulability, and endothelial injury.

Modern Therapies

The transition from traditional anticoagulants like warfarin to direct oral anticoagulants (DOACs) has marked significant progress in DVT management. DOACs like rivaroxaban and apixaban have simplified treatment regimens and improved patient compliance.

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Self-assessment MCQs (single best answer)

What is the most common location for a deep vein thrombosis to form?

Which of the following symptoms is NOT commonly associated with DVT?

Which test is primarily used to confirm the diagnosis of DVT?

What is the most significant complication of DVT?

Which scoring system is used to categorise the likelihood of DVT?

Which anticoagulant is first-line treatment for DVT?

Which imaging technique is NOT commonly used to diagnose DVT?

Which preventive measure is NOT typically recommended to reduce the risk of DVT?

Which historical figure's work laid the foundation for the modern understanding of DVT?

Which of the following is NOT a direct oral anticoagulant (DOAC) used for treating DVT?