Virchow's triad

The Virchow 's triad describes the causal factors of the formation of thrombosis or a DVT (deep vein thrombosis). It is named after the German pathologist Rudolf Virchow ( 1821-1902 ). Thus acting on the development of thrombosis in three main factors:

• Endothelalterationen ( changes or damage to the vessel wall ): Virchow noted that blood clots mainly emerge where the vessel wall is no longer intact. A normal inner vessel wall (endothelium ) is quite smooth. Inflammation or injury make them rough. Thus, the following mechanism is possible: In flowing blood, it constantly comes to clot formation, but which is made ​​just as quickly undone. Happened, however, as a begriffenes emerging "mini clot " a rough spot in the vessel wall, so it sticks there. Thus, the starting point for the development of thrombosis is created. More " Minithromben " put on this thrombus on it, so that it finally comes to vessel occlusion. The causes of such that the vessel wall inflammation roughening processes are varied. Examples of inflammation: phlebitis (inflammation of veins), arteritis (inflammation of the arteries), endocarditis (inflammation of the endocardium ).

• Changes in blood velocity: Virchow noted that clots occur more frequently there where the blood flows evenly and not in the usual speed. In the arterial system, thrombi therefore form preferentially at the points of division (large artery divides into two smaller ones or are from a side arm ), because it comes at the division point to turbulence. In expanded vessel sections ( varicose veins, aneurysms ) the Fließgeschwingkeit drops. Vortex formation (eg, aneurysm, aneurysm in a blood vessel ), varices ( varicose veins ), heart defects ( heart defects eg flaps)

• Changes in blood viscosity: Finally, Virchow noted that " thick " blood clot more easily than " thin ". This property is referred to as the viscosity of liquids. Thickened blood can occur by dehydration ( little drink, dry air), but also by increased sweating (severe labor, fever).

Regardless of the Virchow 's triad plays for the formation of thrombi, the clotting tendency of the blood an important role, for example, the lack of physiological inhibitors of blood coagulation (eg, antithrombin III)