Superior mesenteric artery blood flow in man measured with intra-arterial Doppler catheters: Effect of octreotide

Abstract

Changes in splanchnic blood flow are important in the pathogenesis of portal hypertension, but research in this area is hampered by the difficulty in measuring splanchnic arterial blood flow in man. We therefore investigated the use of intra-arterial Doppler catheters in measuring superior mesenteric artery blood flow in man and assessed the effect of intravenous octreotide on superior mesenteric artery blood flow in a placebo-controlled double-blind study. Nine experiments were performed in a flow model using vessels with internal diameters of 6.5, 4.5 and 3.0 mm, with flow rates ranging from 50 to 700 ml/min. In this model the catheters gave instantaneous, reproducible measurements of blood flow in vessels of 6.5 mm internal diameter with a mean error ranging from +5.3% to +36.4%, compared to electromagnetic flowmetry, but were less accurate in smaller vessels. When used in patients, the catheters provided stable, reproducible measurements of superior mesenteric blood flow, in 16 out of 20 patients studied. In a double-blind placebo-controlled study, including 12 subjects, superior mesenteric artery blood flow was significantly reduced in patients receiving octreotide. We suggest that measurement of splanchnic arterial blood flow using intra-arterial Doppler catheters may be a useful additional investigation in the assessment of splanchnic vascular pathophysiology and pharmacology in man.