Endoscopic ultrasonographic study of the azygos vein before and after endoscopic obliteration of esophagogastric varices by injection sclerotherapy.

Abstract

The azygos vein plays an important role as a drainage system for the superior portosystemic collateral circulation in portal hypertensive patients. Endoscopic ultrasonography (EUS) and Doppler EUS allow the performance of hemodynamic studies of the azygos vein. In this study, we observed the changes in the azygos vein which occur with variceal obliteration by endoscopic injection sclerotherapy (EIS). We recruited patients with portal hypertension and bleeding varices who were not on portal pressure-lowering agents and who were scheduled for the EIS program. EUS was performed in these patients to study the azygos vein at the start of EIS. The azygos vein diameter, maximal velocity (Vmax), and blood flow volume index (BFVI) were measured. After variceal obliteration and within 1 week, another EUS study of the azygos vein was carried out. Out of 40 patients recruited into the study variceal obliteration and EUS assessment of the azygos vein, within 1 week of obliteration, was achieved in 33. We noticed a significant increase in azygos vein diameter (P<0.001) and BFVI (P=0.001) following variceal obliteration. No significant change was observed in Vmax (P>0.05). In one patient, marked caliber irregularities were observed in the azygos vein after variceal obliteration. Using EUS and Doppler EUS, hemodynamic studies of the azygos vein blood flow can be performed, allowing the monitoring of the effects of EIS and variceal obliteration on the superior portosystemic collateral circulation. The clinical significance of the observed changes in azygos blood flow that occur with variceal obliteration should be investigated in further studies and correlated with short-term and long-term outcome.