Validation of color Doppler EUS for azygos blood flow measurement in patients with cirrhosis: application to the acute hemodynamic effects of somatostatin, octreotide, or placebo

Background: Color Doppler EUS (CD-EUS) allows minimally invasive measuremen t of azygos blood flow (AzBF) in portal hypertension, but further validatio n of the method is needed. Because a limited number of patients has been st udied, 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 chan ges in AzBF over a 60-minute period after intravenous administration of som atostatin, 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 a lone, the hemodynamic study was extended to a further 20 patients (phase 2) , In addition, gastric mucosal perfusion changes were assessed by using las er 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 administra tion (-47% and -23%, p < 0.0001 vs, placebo, p = 0.058 vs, placebo, respect ively). After 60 minutes of somatostatin infusion, AzBF increased 27% over placebo values (p < 0.04). Gastric mucosal perfusion was transiently reduce d 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 wi th reference to the invasive thermodilution technique in cirrhosis, It conf irmed the transient effects of somatostatin and octreotide on both AzBF and gastric mucosal perfusion. In addition, a significant rebound phenomenon a fter 60 minutes of continuous intravenous somatostatin infusion was observe d.