Circulatory Diseases and Disorders

A thrombus is formed by the aggregation of platelets, blood cells, fibrin, and other coagulation cascade components that collectively adhere to the vessel wall and occlude the lumen. Arterial (case 5.1) or venous (case 5.2) thrombi that are formed in pathophysiological states can lead to embolic events in which a portion of a thrombus detaches, relocates, and obstructs blood flow in a different part of the vasculature. Both thrombi and emboli can, in severe cases of vascular blockage, lead to ischemic tissue injury and organ damage. In certain clinical contexts (e.g. sepsis, pregnancy, cancer), intravascular microthrombus formation (case 5.3) can lead to disseminated intravascular coagulation and subsequent organ failure and uncontrolled hemorrhage.