Editing Virchow's triad

{{Short description|Three factors thought to cause internal blood clots (thrombosis)}}
{{Infobox medical condition
 |name          =
 |synonym       =
 |image         = Virchow's Triad.svg
 |image_size    =
 |alt           =
 |caption       = Virchow's triad
 |pronounce     =
 |specialty     = <!--from Wikidata; can be overwritten-->
 |symptoms      =
 |complications =
 |onset         =
 |duration      =
 |types         =
 |causes        =
 |risks         =
 |diagnosis     =
 |differential  = thrombosis
 |prevention    =
 |treatment     =
 |medication    =
 |prognosis     =
 |frequency     =
 |deaths        =
}}
'''Virchow's triad''' or the '''triad of Virchow''' ({{IPAc-en|ˈ|f|ɪər|k|oʊ}}) describes the three broad categories of factors that are thought to contribute to [[thrombosis]].<ref name="isbn0-894-355-0">{{cite book
|author1=April Wang Armstrong |author2=David E. Golan |author3=Armen H. Tashjian |author4=Ehrin Armstrong |title=Principles of pharmacology: the pathophysiologic basis of drug therapy
|publisher=Wolters Kluwer Health/Lippincott Williams & Wilkins
|location=Philadelphia
|year=2008
|page=396 
|isbn=978-0-7817-8355-2}}</ref>
* [[Hypercoagulability]]
* [[Hemodynamic]] changes (stasis, turbulence)<ref name="pmid15692260" />
* [[Endothelial]] injury/dysfunction

It is named after the renowned [[Germany|German]] [[physician]] [[Rudolf Virchow]] (1821–1902). However, the elements comprising Virchow's triad were not proposed by Virchow. Neither did he ever suggest a triad to describe the pathogenesis of venous thrombosis. In fact, it was not until decades after Virchow's death that 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 is similar to the description provided by Virchow. Virchow's triad remains a useful concept for clinicians and pathologists alike in understanding the contributors to thrombosis.<ref name="pmid18783400">{{cite journal
|vauthors=Bagot CN, Arya R |title=Virchow and his triad: a question of attribution
|journal=Br. J. Haematol.
|volume=143
|issue=2
|pages=180–190
|date=October 2008
|pmid=18783400
|doi=10.1111/j.1365-2141.2008.07323.x|doi-access=free
}}</ref>
__TOC__

==The triad==
The triad consists of three components:

{| class="wikitable"
|-
! Virchow's<ref name="isbn1-4020-6649-X">{{cite book
|author=Malone, P. Colm, Agutter, Paul S.
|title=The Aetiology of Deep Venous Thrombosis: A Critical, Historical and Epistemological Survey
|publisher=Springer
|location=Paris
|year=2008
|page=84
|isbn=978-1-4020-6649-8
|url=https://books.google.com/books?id=TUfRqCH0smoC
|access-date=2021-12-06
|archive-date=2022-10-15
|archive-url=https://web.archive.org/web/20221015023707/https://books.google.com/books?id=TUfRqCH0smoC
|url-status=live
}}</ref>
! Modern
! Notes
|-
| Phenomena of interrupted blood-flow
| '''[[Venous stasis|Stasis]]''' <ref name="pmid15692260">{{cite journal
|author=Lowe GD
|title=Virchow's triad revisited: abnormal flow
|journal=Pathophysiol. Haemost. Thromb.
|volume=33
|issue=5–6
|pages=455–457
|year=2003
|pmid=15692260
|doi=10.1159/000083845
|doi-access=free
}}</ref>
| The first category, alterations in normal blood flow, refers to several situations. These include [[venous stasis]], long surgical operations, prolonged immobility (whilst on a long plane or car ride, bed bound during hospitalization), and [[varicose veins]]. The equivalence of Virchow's version and the modern version has been disputed.<ref name="urlFurther reflections on Virchows triad. - Free Online Library">{{cite web
|url=http://www.thefreelibrary.com/Further+reflections+on+Virchow%27s+triad.(Letter+to+the+Editor)-a0128075135
|title=Further reflections on Virchow's triad. |via=Free Online Library
|access-date=2009-02-10
|archive-date=2016-03-05
|archive-url=https://web.archive.org/web/20160305013022/http://www.thefreelibrary.com/Further+reflections+on+Virchow%27s+triad.%28Letter+to+the+Editor%29-a0128075135
|url-status=dead
}}</ref>
|-
| 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]] includes vessel piercings and damages arising from [[shear stress]] or [[hypertension]]. This category is ruled by [[Surface science|surface phenomena]] and contact with procoagulant surfaces, such as [[bacteria]], shards of foreign materials, [[biomaterials]] of [[Implant (medicine)|implants]] or [[medical devices]], [[cell membrane|membranes]] of activated [[platelets]], and membranes of [[monocytes]] in [[inflammation|chronic inflammation]].
|-
| Phenomena of blood-coagulation
| '''[[Hypercoagulability]]'''
| The last category, alterations in the constitution of blood,<ref name="pmid15692259">{{cite journal
|vauthors=Chung I, Lip GY |title=Virchow's triad revisited: blood constituents
|journal=Pathophysiol. Haemost. Thromb.
|volume=33
|issue=5–6
|pages=449–454
|year=2003
|pmid=15692259
|doi=10.1159/000083844
|doi-access=free
}}</ref> has numerous possible risk factors such as [[hyperviscosity]], coagulation factor V Leiden mutation, coagulation factor II G2021A mutation, deficiency of [[antithrombin]] III, protein C or S deficiency,  [[nephrotic syndrome]], changes after severe [[Physical trauma|trauma]] or burn, [[cancer]], late pregnancy and delivery, race, advanced age, cigarette smoking, hormonal contraceptives, and [[obesity]].  All of these risk factors can cause the situation called [[hypercoagulability]] (excessively easy clotting of blood).
|}

==History==
The origin of the term "Virchow's Triad" is of historical interest, and has been subject to reinterpretation in recent years.<ref>{{cite journal
|author=Dickson, B.C.
|title=Venous thrombosis: on the history of Virchow's triad
|journal=University of Toronto Medical Journal
|year=2004
|volume=81
|pages=166–171
|url=http://utmj.org/archive/81-3/HIST.pdf
|access-date=2012-05-09
|archive-date=2016-03-05
|archive-url=https://web.archive.org/web/20160305060746/http://utmj.org/archive/81-3/HIST.pdf
|url-status=dead
}}</ref> While both Virchow's and the modern triads describe [[thrombosis]], the previous triad has been characterized as "the consequences of thrombosis", and the modern triad as "the causes of thrombosis".<ref name="urlResponse: further reflections on Virchows Triad. - Free Online Library">{{cite web
|url=http://www.thefreelibrary.com/Response%3a+further+reflections+on+Virchow%27s+Triad.(Letter+to+the...-a0128075136
|title=Response: further reflections on Virchow's Triad. |via= Free Online Library
|access-date=2009-02-10
|archive-date=2016-03-03
|archive-url=https://web.archive.org/web/20160303182629/http://www.thefreelibrary.com/Response%3A+further+reflections+on+Virchow%27s+Triad.%28Letter+to+the...-a0128075136
|url-status=dead
}}</ref>

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.<ref>{{cite book
|author=Virchow, R.
|title=Gesammelte Abhandlungen zur wissenschaftlichen Medicin
|url=https://archive.org/details/b20419089
|location= Frankfurt am Main
|publisher=Von Meidinger & Sohn
|year=1856
|chapter=Thrombose und Embolie. Gefässentzündung und septische Infektion
|pages=[https://archive.org/details/b20419089/page/219 219]–226
|language=de}}{{cite book
|vauthors=Matzdorff AC, Bell WR |title=Thrombosis and embolie (1846–1856)
|location=Canton, Massachusetts
|publisher=Science History Publications
|year=1998 |isbn=0-88135-113-X}}</ref> 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,<ref name="urlVirchows triad? - Free Online Library">{{cite web
|url=http://www.thefreelibrary.com/Virchow%27s+triad%3F-a0123332713
|title=Virchow's triad? |via=Free Online Library
|access-date=2009-02-10
|archive-date=2016-03-04
|archive-url=https://web.archive.org/web/20160304100549/http://www.thefreelibrary.com/Virchow%27s+triad%3F-a0123332713
|url-status=dead
}}</ref><ref>Wiseman R. ''Several Chirurgical Treatises''. (2nd ed.) London, Norton and Macock, 1686, pp. 64–66.</ref> 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.<ref name="isbn1-4020-6649-X" />

Although the concept of the triad is usually attributed to Virchow, he did not include endothelial injury in his description.<ref>{{WhoNamedIt|synd|1223}}</ref> 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.<ref name="urlVirchows triad revisited. - Free Online Library">{{cite web
|url=http://www.thefreelibrary.com/Virchow%27s+triad+revisited.(Letters+to+the+Editor)(Letter+to+the...-a0114134751
|title=Virchow's triad revisited. |via=Free Online Library
|access-date=2009-02-10
|archive-date=2016-03-03
|archive-url=https://web.archive.org/web/20160303230758/http://www.thefreelibrary.com/Virchow%27s+triad+revisited.%28Letters+to+the+Editor%29%28Letter+to+the...-a0114134751
|url-status=dead
}}</ref><ref>Aschoff L. ''Thrombosis, in Lectures on Pathology''. New York, Paul B. Hoeber, Inc., 1924, pp 253–278.</ref>

==References==
{{reflist|2}}

{{Bleeding and clotting disorders|us=y}}

[[Category:Hematology]]
[[Category:Rudolf Virchow]]
[[Category:Medical triads]]