Improvement of the flow properties of blood: a new therapeutical approach in occlusive arterial disease.

The general pathophysiological basis in occlusive arterial disease is the reduced flow rate of blood in the microcirculation. Blood flow in the ischemic tissue can be increased by improving the flow properties of blood. The fibrinogen concentration of blood and the deformability of red cells are two main factors determining the flow properties of blood. Ancrod, a fibrinogen-lowering substance, improves the flow properties of blood by decreasing the viscosity of blood and plasma and by desaggregation of erythrocyte aggregates. Treatment of patients suffering from severe occlusive arterial diseases with Ancrod exhibits surprisingly good results. Disappearance of rest pains and reduction in the use of analgetic drugs has been proved statistically. In the exercising muscles a local hyperosmolarity exists, which is able to decrease the deformability of red cells thereby impairing the flow in narrow capillaries. The addition of Pentoxifyllin to blood in-vitro reduces the rigidity of red cells in hyperosmolar blood samples by increasing their cellular ATP-content. Thus the reduced flow rate of hyperosmolar blood through 8 mu-capillaries could be increased twice (p less than 0.0005) by the addition of Pentoxifyllin. These in-vitro results could be the starting point of a new idea for the treatment of patients with intermittent claudication.