Hemodynamic effects of vasodilators across iliac stenoses in dogs

Blood flow and pressure gradients were measured in dogs across externally applied iliac artery stenoses following 3 minutes of reactive hyperemia and injection of tolazoline (0.4 mg/kg), papaverine (0.04 mg/kg), and prostaglandin E1 (0.033 micrograms/kg) into the iliac artery. Stenoses of borderline and definite hemodynamic significance at rest were produced. The gradients produced with all four modalities of vasodilatation following borderline stenosis were significantly greater than those produced with each modality before the induction of stenosis. The peak effects of all modes of vasodilatation occurred within 30 seconds, although the effects of prostaglandin E1 were continued the longest. Our results indicate that pharmacologic or reactive hyperemia can help assess the significance of borderline iliac stenoses in patients with intermittent claudication.