Background: Color Doppler EUS (CD-EUS) allows minimally invasive measurement of azygos blood flow (AzBF) in portal hypertension, but further validation of the method is needed. Because a limited number of patients has been studied, the acute hemodynamic effects of somatostatin and octreotide on AzBF and gastric mucosal perfusion are poorly defined in portal hypertension.
Methods: A double-blind hemodynamic study was designed to assess rapid changes in AzBF over a 60-minute period after intravenous administration of somatostatin, octreotide, and placebo in 30 stable patients with biopsy-proven cirrhosis. AzBF was measured by using both CD-EUS and the invasive thermal dilution technique in the first 10 patients (phase 1). Then, with CD-EUS alone, the hemodynamic study was extended to a further 20 patients (phase 2). In addition, gastric mucosal perfusion changes were assessed by using laser Doppler flowmetry at endoscopy.
Results: In phase 1, the 2 methods for AzBF measurement showed significant correlations both for baseline values (r = 0.685) and for AzBF changes over 60 minutes after drug administration (r = 0.733). In phase 2, a reduction was observed in AzBF 10 minutes after octreotide or somatostatin administration (-47% and -23%, p < 0.0001 vs. placebo, p = 0.058 vs. placebo, respectively). After 60 minutes of somatostatin infusion, AzBF increased 27% over placebo values (p < 0.04). Gastric mucosal perfusion was transiently reduced 5 minutes after octreotide or somatostatin (-21% and -32%, respectively, p < 0.02 vs. placebo).
Conclusions: This is the first study to validate CD-EUS AzBF measurement with reference to the invasive thermodilution technique in cirrhosis. It confirmed the transient effects of somatostatin and octreotide on both AzBF and gastric mucosal perfusion. In addition, a significant rebound phenomenon after 60 minutes of continuous intravenous somatostatin infusion was observed.