Deep vein thrombosis (DVT) is the development of a blood clot within a vein deep to the muscular tissue planes. DVT most commonly affects the legs, but can also affect the arms, and other sites in the body.
Patients who develop DVT commonly have risk factors, such as cancer, trauma, major surgery, hospitalization, immobilization, pregnancy, or oral contraceptive use. DVT may also be unprovoked (idiopathic) and occur in the absence of any identifiable extrinsic risk factors.
DVTs commonly cause asymmetrical leg swelling, unilateral leg pain, dilation or distension of superficial veins, and red or discolored skin, but can also be asymptomatic.
Assessment of pretest probability (using a validated score such as Wells score) is key if DVT is suspected, and should be used in combination with an algorithmic diagnostic approach to avoid unnecessary imaging when the likelihood of DVT is low.
Diagnosis requires confirmation of a blood clot in a deep vein in the leg, pelvis, or vena cava by venous duplex ultrasound imaging or computed tomography scan.
DVT is usually treated with anticoagulants such as unfractionated heparin, low molecular weight heparin, fondaparinux, rivaroxaban, apixaban, edoxaban, dabigatran, and/or warfarin. Interventional therapies, including thrombolysis, are rarely indicated.
Generally, anticoagulant therapy for at least 3 months is required for patients with DVT. Thereafter, continued anticoagulant therapy for secondary prevention is indicated in selected patients to reduce the risk of recurrent events.
Post-thrombotic syndrome may occur with symptoms of chronic pain, swelling, skin discoloration, or venous ulcers following chronic obstruction of venous outflow and/or incompetence of venous valves.
DVT is the development of a blood clot in a major deep vein in the leg, thigh, pelvis, or abdomen. It may also occur in less common locations such as the arm veins; the portal, mesenteric, ovarian, or retinal veins; or the veins and venous sinuses of the brain. DVT can result in impaired venous blood flow and consequent swelling and pain. DVT is rarely life-threatening on its own, but has the potential to cause pulmonary embolism (PE), which can be fatal. Venous thromboembolism is the broad term that includes DVT and PE. Superficial vein thrombosis, a common related condition, affects veins superficial to the musculature. This topic focuses on lower and upper extremity DVT.
History and exam
Key diagnostic factors
- calf swelling
- localized pain along deep venous system
Other diagnostic factors
- asymmetric edema
- prominent superficial veins
- swelling of the entire leg
- phlegmasia cerulea dolens
- major surgery within the preceding 3 months
- medical hospitalization within the preceding 2 months
- active cancer
- previous venous thromboembolic event
- recent trauma or fracture
- increasing age
- pregnancy and the postpartum
- paralysis of the lower extremities
- factor V Leiden
- prothrombin gene G20210A mutation
- protein C or protein S deficiency
- antithrombin deficiency
- antiphospholipid syndrome
- medical comorbidity
- use of specific drugs
- cigarette smoking
- recent long-distance air travel
- family history
- central venous catheterization
1st investigations to order
- Wells score
- quantitative D-dimer level
- proximal duplex ultrasound
- whole-leg ultrasound
- INR and activated partial thromboplastin time (aPTT)
- BUN and creatinine
Investigations to consider
- Doppler venous flow testing
- CT abdomen and pelvis with contrast
- thrombophilia screen
initiation-phase therapy: no active bleeding
initiation-phase therapy: active bleeding
extended-phase therapy (3 months’ anticoagulation therapy completed): not postpartum, no recurrence
extended-phase therapy: postpartum (planning to breastfeed)
extended-phase therapy: postpartum (not planning to breastfeed)
extended-phase therapy: recurrent VTE
- Calf muscle tear/Achilles tendon tear
- Calf muscle hematoma
- NCCN clinical practice guidelines in oncology: cancer-associated venous thromboembolic disease
- Clinical practice guidelines on the management of venous thrombosis
Deep vein thrombosis
DVT and long-distance travelMore Patient leaflets
Modified Wells score for deep vein thrombosis (DVT)
Pretest Probability of Heparin Induced Thrombocytopenia (4-T's score)More Calculators
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