Virchow's triad
Encyclopedia
Virchow's triad describes the three broad categories of factors that are thought to contribute to thrombosis
.
It is named for German
physician
Rudolf Virchow
(1821-1902). However, the elements comprising Virchow's triad were neither proposed by Virchow, nor did he ever suggest a triad to describe the pathogenesis of venous thrombosis. In fact, it was decades following Virchow's death before a consensus was reached proposing that thrombosis is the result of alterations in blood flow, vascular endothelial injury, or alterations in the constitution of the blood.
Still, the modern understanding of the factors leading to embolism are similar to the description provided by Virchow.
Its nebulous origins notwithstanding, Virchow's triad remains a useful concept for clinicians and pathologists alike in understanding the contributors to venous, and perhaps arterial, thrombosis. While the triad is now frequently applied to describe thrombosis arising within the arterial circulation, many continue to restrict it to that occurring within the venous vasculature.
While both triads describe thrombosis
, Virchow's triad has been characterized as "the consequences of thrombosis", and the modern triad as "the causes of thrombosis".
Rudolf Virchow
elucidated the etiology of pulmonary embolism
, whereby thrombi occurring within the veins, particularly those of the extremities, become dislodged and migrate to the pulmonary vasculature. He published his description in 1856. In detailing the pathophysiology
surrounding pulmonary embolism
, he alluded to many of the factors known to contribute to venous thrombosis. While these factors had already been previously established in the medical literature by others, for unclear reasons they ultimately became known as Virchow's triad. This eponym
did not emerge in the literature until long after Virchow's death. One estimate of the first use of the phrase dates it to the early 1950s.
Although the concept of the triad is usually attributed to Virchow, he did not include endothelial injury in his description. This has been attributed to a dispute Virchow had with Jean Cruveilhier
, who considered local trauma of primary importance in the development of pulmonary artery thrombosis.
Thrombosis
Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...
.
- Hypercoagulability
- Hemodynamic changes (stasis, turbulence)
- Endothelial injury/dysfunction
It is named for German
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
physician
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...
Rudolf Virchow
Rudolf Virchow
Rudolph Carl Virchow was a German doctor, anthropologist, pathologist, prehistorian, biologist and politician, known for his advancement of public health...
(1821-1902). However, the elements comprising Virchow's triad were neither proposed by Virchow, nor did he ever suggest a triad to describe the pathogenesis of venous thrombosis. In fact, it was decades following Virchow's death before a consensus was reached proposing that thrombosis is the result of alterations in blood flow, vascular endothelial injury, or alterations in the constitution of the blood.
Still, the modern understanding of the factors leading to embolism are similar to the description provided by Virchow.
Its nebulous origins notwithstanding, Virchow's triad remains a useful concept for clinicians and pathologists alike in understanding the contributors to venous, and perhaps arterial, thrombosis. While the triad is now frequently applied to describe thrombosis arising within the arterial circulation, many continue to restrict it to that occurring within the venous vasculature.
The triad
The triad consists of three components:| Virchow's | Modern | Notes |
|---|---|---|
| phenomena of interrupted blood-flow | "stasis" or "venous stasis" | The first category, alterations in normal blood flow, refers to several situations. These include turbulence Turbulence In fluid dynamics, turbulence or turbulent flow is a flow regime characterized by chaotic and stochastic property changes. This includes low momentum diffusion, high momentum convection, and rapid variation of pressure and velocity in space and time... , stasis Stasis (medicine) In medicine, stasis is the state in which the normal flow of a body liquid stops, for example the flow of blood through vessels or of intestinal contents through the digestive tract.... , mitral stenosis Mitral stenosis Mitral stenosis is a valvular heart disease characterized by the narrowing of the orifice of the mitral valve of the heart.-Signs and symptoms:Symptoms of mitral stenosis include:... , and varicose veins Varicose veins Varicose veins are veins that have become enlarged and tortuous. The term commonly refers to the veins on the leg, although varicose veins can occur elsewhere. Veins have leaflet valves to prevent blood from flowing backwards . Leg muscles pump the veins to return blood to the heart, against the... . The equivalence of Virchow's version and the modern version has been disputed. |
| phenomena associated with irritation of the vessel and its vicinity | "endothelial injury" or "vessel wall injury" | The second category, injuries and/or trauma to endothelium Endothelium The endothelium is the thin layer of cells that lines the interior surface of blood vessels, forming an interface between circulating blood in the lumen and the rest of the vessel wall. These cells are called endothelial cells. Endothelial cells line the entire circulatory system, from the heart... includes damage to the veins arising from shear stress Shear stress A shear stress, denoted \tau\, , is defined as the component of stress coplanar with a material cross section. Shear stress arises from the force vector component parallel to the cross section... or hypertension Hypertension Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and... . |
| phenomena of blood-coagulation | "hypercoagulability" | The last category, alterations in the constitution of blood, has numerous possible risk factors such as hyperviscosity, deficiency of antithrombin Antithrombin Antithrombin is a small protein molecule that inactivates several enzymes of the coagulation system. Antithrombin is a glycoprotein produced by the liver and consists of 432 amino acids. It contains three disulfide bonds and a total of four possible glycosylation sites... III, nephrotic syndrome Nephrotic syndrome Nephrotic syndrome is a nonspecific disorder in which the kidneys are damaged, causing them to leak large amounts of protein from the blood into the urine.... , changes after severe trauma Physical trauma Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death... or burn, disseminated cancer, late pregnancy and delivery, race, age, whether the patient is a smoker, and obesity Obesity Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems... . All of these risk factors cause the situation called hypercoagulability. |
While both triads describe thrombosis
Thrombosis
Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...
, Virchow's triad has been characterized as "the consequences of thrombosis", and the modern triad as "the causes of thrombosis".
History
The origin of the term "Virchow's Triad" is of historical interest, and has been subject to reinterpretation in recent years.Rudolf Virchow
Rudolf Virchow
Rudolph Carl Virchow was a German doctor, anthropologist, pathologist, prehistorian, biologist and politician, known for his advancement of public health...
elucidated the etiology of pulmonary embolism
Pulmonary embolism
Pulmonary embolism is a blockage of the main artery of the lung or one of its branches by a substance that has travelled from elsewhere in the body through the bloodstream . Usually this is due to embolism of a thrombus from the deep veins in the legs, a process termed venous thromboembolism...
, whereby thrombi occurring within the veins, particularly those of the extremities, become dislodged and migrate to the pulmonary vasculature. He published his description in 1856. In detailing the pathophysiology
Pathophysiology
Pathophysiology is the study of the changes of normal mechanical, physical, and biochemical functions, either caused by a disease, or resulting from an abnormal syndrome...
surrounding pulmonary embolism
Pulmonary embolism
Pulmonary embolism is a blockage of the main artery of the lung or one of its branches by a substance that has travelled from elsewhere in the body through the bloodstream . Usually this is due to embolism of a thrombus from the deep veins in the legs, a process termed venous thromboembolism...
, he alluded to many of the factors known to contribute to venous thrombosis. While these factors had already been previously established in the medical literature by others, for unclear reasons they ultimately became known as Virchow's triad. This eponym
Eponym
An eponym is the name of a person or thing, whether real or fictitious, after which a particular place, tribe, era, discovery, or other item is named or thought to be named...
did not emerge in the literature until long after Virchow's death. One estimate of the first use of the phrase dates it to the early 1950s.
Although the concept of the triad is usually attributed to Virchow, he did not include endothelial injury in his description. This has been attributed to a dispute Virchow had with Jean Cruveilhier
Jean Cruveilhier
Jean Cruveilhier was a French anatomist and pathologist.In 1816 he earned his doctorate in Paris, where in 1825 he succeeded Pierre Augustin Béclard as professor of anatomy...
, who considered local trauma of primary importance in the development of pulmonary artery thrombosis.