Basic Science – Cell Based Model of Haemostasis

The complex process of coagulation that leads to hemostasis has been described by several models in the past, the most popular of which was the cascade model. Though the cascade model (with intrinsic, extrinsic and common pathway) was a good description of this process in vivo, it fails to account for several experimental and clinical findings that have come to light in the last few decades. The in vitro activation of the coagulation process (the basis of the cascade model) doesn’t completely represent the global haemostatic process that occurs in vivo, characterised by interactions between tissue factor bearing cells, platelets and the intrinsic and extrinsic pathways. The cell-based model of haemostasis is the currently accepted model as it better reflects the process of haemostasis in vivo. It consists of three overlapping phases – initiation, amplification and propagation phases. It overcomes many of the limitations of the cascade model and is clinically relevant.