The effect of hemodilution upon patients with intermittent claudication.

Seventeen patients with stable intermittent claudication and a PCV of more than 0.45 were venesected until a PCV of 0.35 was achieved. Only patients that were not considered candidates for surgical treatment were entered into the study. Each patient acted as their own control and was studied twice before the venesection at a mean PCV of 0.49 then after achieving a PCV of 0.35 or less (mean PCV of 0.33), and finally one month after the last venesection (mean PCV of 0.37). Angina developed in one patient after the third venesection and was withdrawn from the study. In the remaining sixteen patients, blood flow of the calf muscle during exercise increased significantly after venesection from 5.90 to 8.84 milliliters per 100 grams per minute (p = 0.02). This was measured by xenon 133 clearance and a cadmium telluride detector. There was also a substantial decrease (p less than 0.001) in whole blood viscosity at both low and high shear stresses, but there was no change in plasma viscosity or plasma fibrinogen. Treadmill claudication distance improved in only two patients. Ten patients were tired when the PCV decreased to 0.35 and subjective claudication distance deteriorated in four of these patients. Subsequent isovolemic venesection with dextran 70 volume replacement to a PCV of 0.35 did not improve the response in the six patients restudied. We conclude that venesection did not benefit these patients with intermittent claudication and there was an unacceptable incidence of side effects. Therefore, we suggest that reducing the PCV to 0.35 should be avoided in patients with intermittent claudication who have been refused surgical treatment.