Venous thrombogenesis.

The various factors that may be responsible for converting fluid blood into stasis thrombi in the deep veins of the legs are reviewed in relation to some recent experimental data. While stasis promotes the passage of white blood cells through the vascular endothelium, such emigration does not by itself lead to subsequent thrombus formation. Similarly, mechanical crushing of the vein, with exposure of the subendothelium, is not associated with fibrin deposition, and appears to be a relatively poor thrombogenic stimulus. In contrast, trace amounts of an activated clotting factor, combined with local stasis, produce venous thrombi within minutes.