Effect of somatostatin versus octreotide on portal haemodynamics in patients with cirrhosis and portal hypertension

OBJECTIVES: Elevated portal inflow is part of the pathogenesis of portal hypertension in patients with cirrhosis. Vasoactive substances appear to play a primary role in the regulation of portal flow. The aim of this study was to investigate the effects of somatostatin and octreotide on portal pressure and plasma levels of insulin-like growth factor (IGF-1), nitric oxide (NO), endothelin-1 (ET-1) and glucagon (GLU). METHODS: Portal pressures of 14 cirrhotic patients with portal hypertension who underwent transjugular intrahepatic portosystemic shunt (TIPS) were directly measured via a catheter placed in the portal vein. Portal pressure and IGF-1, NO, ET-1 and GLU plasma levels were determined at baseline, and at 8 h and 24 h after administration of somatostatin or octreotide via portal vein catheter in a randomized, double-blind, cross-over design. RESULTS: The average decrease in portal pressure after intravenous infusion of somatostatin and octreotide was 9.4 +/- 1.0 cmH2O and 5.0 +/- 1.0 cmH2O, respectively (P < 0.01). Plasma levels of GLU and IGF-1 decreased significantly 8 and 24 h after somatostatin and octreotide infusion (P < 0.05). However, there were no significant decreases in plasma NO or ET-1 levels. There was a significant difference between somatostatin and octreotide groups (P < 0.01). CONCLUSION: Both somatostatin and octreotide can significantly reduce portal pressure, although somatostatin is more potent than octreotide. The underlying mechanisms may involve inhibition of the secretion of GLU, IGF-1 and other hormones as well as a decrease in hepatic metabolism and portal inflow leading to a reduction in portal pressure.