Red cell aggregability increases with the severity of venous insufficiency

Several studies have suggested the presence of hemorheological abnormalities in venous insufficiency. The present prospective study was carried out to determine whether the increase in hemorheological disturbances parallels the evolution of the disease. Patients were recruited among ambulant outpatients and classified in 3 evolution stages of venous insufficiency according to the clinical and functional examination. Once a certain number of patients were included, the following successive inclusions were made in order to match for age and sex, in the other stages of venous insufficiency, the previously included patients. Since blood rheology is frequently altered in hypertension, diabetes and several other vascular pathologies, patients with those pathologies were not included. Sixty nine patients with venous insufficiency and 23 healthy subjects were tested, making up twenty three matching sets. Red blood cell (RBC) aggregation and disaggregation were assessed with the SEFAM erythroaggregameter on blood samples adjusted to 40% hematocrit. Statistical analysis showed a significant difference for the aggregation index (p = 0.0001), disaggregation shear rate (p = 0.0001) and fibrinogen (p = 0.006) between the 4 groups. Aggregability parameters increased gradually with the evolution of the disease, while the fibrinogen rise was significant only when varicose veins were present (stages 2 and 3). This progressive rise in RBC aggregability with the aggravation of venous insufficiency, by superimposing to the haemodynamic deficit, is likely to induce the formation of RBC aggregates in vivo, to perpetuate venous stasis and to contribute to the development of severe skin damages.