RED-BLOOD-CELL AGGREGABILITY IN PATIENTS WITH A HISTORY OF LEG VEIN-THROMBOSIS - INFLUENCE OF POSTTHROMBOTIC TREATMENT

Reversible aggregation of red blood cells (RBC) plays an important rol e in determining blood Bow properties. and it is this aggregation whic h increases blood viscosity at low shear rates. The structure and site s of venous thrombi, as well as the fact that stasis is a major predis posing factor in venous thrombosis, suggest a strong association betwe en vein thrombosis, slow blood now and increased blood viscosity. RBC aggregation and disaggregation were measured (SEFAM erythroaggregamete r. France) in 54 patients with a history of unexplained leg Vein throm bosis. Results were compared to those of controls classified according to age. Increased RBC aggregability was observed in 41% of the patien ts, and the mean values indicated a significant elevation of RBC aggre gability in patients when compared with controls (P < 0.05). Subgroups were compared to study the influence of thrombus recurrence and throm bosis type (deep Versus superficial vein thrombosis) on the aggregatio n parameters. No significant difference was found between these subgro ups. The use of compression stockings and veinotropic drugs tended to reduce the abnormalities in RBC aggregability (P < 0.05). An increase in RBC aggregability and in the shear resistance of RBC aggregates, by predisposing to circulatory stasis, is likely to contribute to the ev olution and complications of leg vein thrombosis.