Use of color Doppler EUS in assessing azygos blood flow for patients with portal hypertension

Background: Azygos blood flow is an index of blood flow through gastroesoph ageal collateral vessels and varices in portal hypertension. Conventional m easurement of azygos blood flow involves catheterization of the azygos vein . We studied the feasibility of assessing azygos blood flow with color Dopp ler endosonography and of monitoring the effects of vasoactive agents on az ygos blood flow. Methods: Patients with portal hypertension were examined by means of linear array color Doppler endoscopic ultrasonography (EUS). Patients who had tak en propranolol or nitrates in the 4 weeks before the day of measurement of azygos blood flow were excluded. After identification of the azygos vein an d recording of baseline readings of mean arterial blood pressure, pulse rat e, and azygos blood flow, patients were selected in a random manner to rece ive a bolus injection of 2 mg terlipressin, 250 mu g somatostatin, or salin e solution (control). Azygos blood flow was measured 1, 5, and 10 minutes a fter injection (AzBF-1,AzBF-5, AzBF-10). Results: Six patients were recruited in each treatment group. Basal azygos blood flow showed a positive association with the Child-Pugh grade of cirrh osis (p < 0.005). After bolus injection of terlipressin and somatostatin, t here was a marked decrease in AzBF-1 (24% and 37%), AzBF-5 (42% and 19%), a nd AzBF-10 (40% both) compared with baseline. The control group showed no s ignificant change in azygos blood flow. Conclusions: Color Doppler EUS is useful in assessing azygos blood flow in portal hypertension and in monitoring the effects of vasoactive agents.