[Thrombophilia, autoimmunity, and perioperative thromboprophylaxis]

Thrombosis is observed in several areas of medicine. Equilibrium between pro- and anticoagulant factors is required for maintaining blood flow. Tissue injury from multiple causes may induce coagulum formation mediated by coagulation pathway activation. Tissue factor (F III) + F VIIa interacts with both platelet and endothelial cell receptors. This coagulation model displays four stages: a) initiation, b) amplification, c) propagation and d) stabilization. Development of thrombosis is associated with either primary or hereditary and acquired factors. Primary thrombophilia is determined genetically by a hypercoagulative state shown by loss of natural anticoagulant activity, such as antithrombin III, C, S protein or procoagulant activity gaining resistance to activated C protein: factor V (Leiden), prothrombin and methylenetetrahydrofolate reductase mutations. Acquired thrombophilia mainly relates to an autoimmune condition such as the presence of anticardiolipin antibodies or lupus anticoagulant. Surgical procedures enhance mechanisms that predispose to thrombosis, e.g., acidosis, hypothermia, plasma expanders, extracorporeal circulation, duration of surgical procedure, and tissue manipulation. Adequate classification of the patient's thrombosis risk and adequate use of primary and secondary prophylactic recommendations in these groups of patients is necessary.