9/27/21, 2:39 PM View Monograph
Diseases and Conditions: Deep vein thrombosis
Deep vein thrombosis
Overview
Thrombus formation in one or more deep veins, usually of the lower extremities
Deep vein thrombosis (DVT) and acute pulmonary embolism (PE) are both manifestations of venous
thromboembolism (VTE)
May be termed provoked or unprovoked
Provoked: Caused by a known event (for example, surgery or hospital admission)
Unprovoked: Not associated with an identifiable provoking environmental event
Two categories of DVT of the lower extremity:
Distal (calf) vein thrombosis: Thrombi remain confined to the deep calf veins
Proximal vein thrombosis: Thrombosis involves the popliteal, femoral, or iliac veins (more commonly
associated with the development of pulmonary emboli)
May be symptomatic or asymptomatic:
Symptomatic: Presence of symptoms usually leads to laboratory or radiologic evaluation
Asymptomatic: Incidental finding occurs on radiologic imaging in a patient without symptoms
Pathophysiology
Three factors (Virchow triad) contribute to thrombosis formation. (See Virchow triad.)
Virchow triad
Virchow triad is a widely known theory that describes three broad factors that are thought to
contribute to thrombosis:
alterations in blood flow (stasis)
vascular endothelial injury
alterations in blood coagulation (hypercoagulability).
Thrombosis occurs when an alteration in the epithelial lining causes platelet aggregation and consequent
fibrin entrapment of red and white blood cells and additional platelets. (See Formation of a venous
thrombus.)
A thrombus can form more rapidly in an area in which blood flows more slowly because of the prolonged
contact between platelets and the accumulation of thrombin.
The rapidly expanding thrombus initiates a chemical inflammatory process in the vessel epithelium, which
leads to fibrosis.
The enlarging clot may partially or totally occlude the vessel lumen, or it may detach and become an
embolus, lodging elsewhere in the circulatory system.
Formation of a venous thrombus
The illustration below shows the formation of a venous thrombus.
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, 9/27/21, 2:39 PM View Monograph
To view the image in PDF format, click on this link.
Causes
Formation of a thrombus
Previous episode(s) of VTE
Lower extremity trauma
Risk Factors
Inherited thrombophilia, such as factor V Leiden, prothrombin gene mutation, protein S or C deficiency, or
antithrombin deficiency
Malignancy
Presence of a central or peripheral venous catheter
Surgery (especially orthopedic)
Trauma, fracture, or severe muscle injury
Pregnancy
Oral contraceptive use
Hormone replacement therapy
History of tamoxifen citrate, thalidomide, or lenalidomide or other chemotherapeutic agent use
Immobilization
Heart failure or lung disease
Antiphospholipid antibody syndrome
Myeloproliferative disorders (disorders that cause platelets as well as red and white blood cells to grow
abnormally in the bone marrow), such as polycythemia vera, essential thrombocytosis, primary or
idiopathic myelofibrosis, and chronic myelogenous leukemia
Paroxysmal nocturnal hemoglobinuria
https://lnareference.wkhpe.com/ref/view.do?key=bc9a84363bbae2169ca062cbdfd6b7a98657fdc0&nmn=openMonographFromGlobalId&monographId… 2/9
Diseases and Conditions: Deep vein thrombosis
Deep vein thrombosis
Overview
Thrombus formation in one or more deep veins, usually of the lower extremities
Deep vein thrombosis (DVT) and acute pulmonary embolism (PE) are both manifestations of venous
thromboembolism (VTE)
May be termed provoked or unprovoked
Provoked: Caused by a known event (for example, surgery or hospital admission)
Unprovoked: Not associated with an identifiable provoking environmental event
Two categories of DVT of the lower extremity:
Distal (calf) vein thrombosis: Thrombi remain confined to the deep calf veins
Proximal vein thrombosis: Thrombosis involves the popliteal, femoral, or iliac veins (more commonly
associated with the development of pulmonary emboli)
May be symptomatic or asymptomatic:
Symptomatic: Presence of symptoms usually leads to laboratory or radiologic evaluation
Asymptomatic: Incidental finding occurs on radiologic imaging in a patient without symptoms
Pathophysiology
Three factors (Virchow triad) contribute to thrombosis formation. (See Virchow triad.)
Virchow triad
Virchow triad is a widely known theory that describes three broad factors that are thought to
contribute to thrombosis:
alterations in blood flow (stasis)
vascular endothelial injury
alterations in blood coagulation (hypercoagulability).
Thrombosis occurs when an alteration in the epithelial lining causes platelet aggregation and consequent
fibrin entrapment of red and white blood cells and additional platelets. (See Formation of a venous
thrombus.)
A thrombus can form more rapidly in an area in which blood flows more slowly because of the prolonged
contact between platelets and the accumulation of thrombin.
The rapidly expanding thrombus initiates a chemical inflammatory process in the vessel epithelium, which
leads to fibrosis.
The enlarging clot may partially or totally occlude the vessel lumen, or it may detach and become an
embolus, lodging elsewhere in the circulatory system.
Formation of a venous thrombus
The illustration below shows the formation of a venous thrombus.
https://lnareference.wkhpe.com/ref/view.do?key=bc9a84363bbae2169ca062cbdfd6b7a98657fdc0&nmn=openMonographFromGlobalId&monographId… 1/9
, 9/27/21, 2:39 PM View Monograph
To view the image in PDF format, click on this link.
Causes
Formation of a thrombus
Previous episode(s) of VTE
Lower extremity trauma
Risk Factors
Inherited thrombophilia, such as factor V Leiden, prothrombin gene mutation, protein S or C deficiency, or
antithrombin deficiency
Malignancy
Presence of a central or peripheral venous catheter
Surgery (especially orthopedic)
Trauma, fracture, or severe muscle injury
Pregnancy
Oral contraceptive use
Hormone replacement therapy
History of tamoxifen citrate, thalidomide, or lenalidomide or other chemotherapeutic agent use
Immobilization
Heart failure or lung disease
Antiphospholipid antibody syndrome
Myeloproliferative disorders (disorders that cause platelets as well as red and white blood cells to grow
abnormally in the bone marrow), such as polycythemia vera, essential thrombocytosis, primary or
idiopathic myelofibrosis, and chronic myelogenous leukemia
Paroxysmal nocturnal hemoglobinuria
https://lnareference.wkhpe.com/ref/view.do?key=bc9a84363bbae2169ca062cbdfd6b7a98657fdc0&nmn=openMonographFromGlobalId&monographId… 2/9
