Purpose: To review recent advances in hemostasis and thrombosis.
Methods: A review of recent studies that have changed our understanding of hemostasis and thrombosis.
Results: The cascade model of coagulation divided coagulation into extrinsic and intrinsic pathways. Factor VIIa/tissue factor complex of the extrinsic system is the major initiating event of hemostasis in vivo. The intrinsic pathway (the contact system) does not play a physiologic role in hemostasis. The cascade model has been replaced with a cell-based model with three overlapping phases: initiation, amplification, and propagation. Although Factors XI and XII of the intrinsic system are not involved in hemostasis, they may have a key role in abnormal hemostasis or thrombosis. The pathways of coagulation and inflammation are intertwined at numerous points. The procoagulant factors, VIIa, Xa, and thrombin can activate members of the protease-activated receptor family, which play an important role in coagulation, inflammation, and vascular hemostasis. Factor V plays a crucial role in both the procoagulant and anticoagulant systems.
Conclusion: New insights into hemostasis provide greater understanding of the causes of both venous and arterial thrombosis.