Deep vein thrombosis

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. DVT can embolize, most commonly in the form of pulmonary embolism (PE) to the lungs, which can be life-threatening.

Patients who develop DVT commonly have thromboembolic 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 asymmetric 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 by venous duplex ultrasound imaging or computed tomography scan.

Phlegmasia cerulea dolens (PCD) is a rare, life- and limb-threatening complication and is characterized by marked swelling, significant pain, and cyanosis. If it is suspected, quick action is needed; the results of investigations should not be waited for before treatment is started.

DVT is usually treated with anticoagulants such as unfractionated heparin, low molecular weight heparin, fondaparinux, direct oral anticoagulants, 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 select 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 splanchnic, 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 PE, which can be fatal. Venous thromboembolism (VTE) is the broad term that includes DVT and PE. Superficial vein thrombosis, a common related condition, affects veins superficial to the musculature. Overall, approximately two-thirds of VTE cases are isolated DVT, and one third are PE (with or without concomitantly diagnosed DVT). As concomitant disease may be asymptomatic, these figures may underestimate the frequency of overlapping disease manifestations.[1]Virani SS, Alonso A, Aparicio HJ, et al; American Heart Association Council on Epidemiology and Prevention Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics - 2021 update: a report from the American Heart Association. Circulation. 2021 Feb 23;143(8):e254-743. https://www.ahajournals.org/doi/epub/10.1161/CIR.0000000000000950 http://www.ncbi.nlm.nih.gov/pubmed/33501848?tool=bestpractice.com

This topic covers DVT in adults and focuses on the diagnosis and management of lower-extremity DVT.