Reduction of renal cortical blood flow assessed by Doppler in cirrhotic patients with refractory ascites

The usefulness in cirrhotic patients of hemodynamic measurements by Doppler ultrasonography (US) is still not defined. We investigated the relationships between Doppler measurements and the severity of ascites. Portal blood flow velocity and volume, and hepatic and renal arterial resistance indexes (RI) were measured in 57 cirrhotic patients (19 without ascites, 28 with responsive ascites, and 10 with refractory ascites) and 15 healthy controls. The renal arterial RI were obtained for the main renal artery, interlobar vessels, and cortical vessels. Cirrhotic patients had decreased portal blood flow and an increased congestion index (CI). Only the CI was correlated to the severity of ascites, showing that it is also a reliable measure of the severity of portal hypertension in patients with ascites. The hepatic and renal artery RI were increased in cirrhotic patients, and the two values were correlated (r = .68; P = .00001). The RI of renal interlobar and cortical vessels were higher in patients with refractory ascites than in patients without ascites (P < .02 and P < .009), and correlated with sodium excretion rate (r = -.45; P < .003), the renin-aldosterone system, and creatinine clearance (r = -.62; P < .0002). The RI decreased from the hilum of the kidney to the outer parenchyma in healthy subjects and patients with responsive ascites, but this difference disappeared in patients with refractory ascites. This indicates that the degree of renal vasoconstriction varies in different areas according to the severity of the ascites. Cortical vessels are involved mainly in patients with refractory ascites, suggesting that the intrarenal blood flow distribution in cirrhosis tends to preserve the cortical area and that severe cortical ischemia is a feature of refractory ascites.