Blood rheology and venous thrombosis

Abstract

Evidence that blood rheology is a causative factor in venous thrombosis of the leg and retina is reviewed. The sites of thrombosis suggest low-shear conditions which favour red cell aggregation, which may potentiate venous stasis and thrombogenesis. Venous thrombosis is also associated with high levels of haematocrit and fibrinogen, which promote red cell aggregation. Reduction in haematocrit or fibrinogen levels appears to reduce the incidence or extent of leg vein thromboembolism. Increased levels of haematocrit and fibrinogen may also promote thrombosis by activation of haemostasis, as well as by promoting venous stasis.