[Hemorheology of venous insufficiency]

The aim of this paper is to study the rheological properties of blood in patients with venous insufficiency.

Measurements have been performed for 20 healthy control subjects and 20 patients presenting a venous insufficiency with varicose veins of lower limbs. Blood has been withdrawn from the veins of the lower limbs at rest and after 10 minutes of venous stasis (standing position and 100 mmHg tourniquet). The following measurements have been performed: hematocrit by microcentrifugation; fibrinogen by nephelometry; plasma viscosity by means of capillary viscosimeter (Myrenne KSPV4); deformability by Hanss hemorheometer using nucleopore membranes and red blood cell aggregation and disaggregation by means of a SEFAM erythro-aggregometer.

1. Hematocrit was not significantly different between both groups of subjects at rest. However, it increased significantly after venous stasis in patients with varicose veins but it was not found to be increased in healthy subjects. 2. Before and after stasis, the fibrinogen level was higher in patients than in controls. After stasis, a significant increased was found only in the patient group. 3. Plasma viscosity was found to be modified as the same manner as the fibrinogen level. Besides, the fibrinogen level and plasma viscosity were found to be correlated to each other. 4. Before and after stasis, red cells of patients were significantly less deformable than those of controls. After stasis, they were found to be more altered, in patients. But there were no difference in controls before and after stasis. 5. Aggregation and disaggregation parameters have been found to be disturbed in patient group. Disturbances were more pronounced after stasis.

Venous insufficiency can be characterized by alteration of rheological parameters and the blood stasis in varicose veins may enhance these alterations. These results indicate the importance of hemorheological disturbances in the pathogenesis of this disease.