Measurement of renal arterial blood flow velocity by Doppler ultrasonography in chronic liver disease

Abstract

Doppler ultrasonography was used to measure hepatic hemodynamics in patients with chronic liver disease. We investigated the relationships among the velocity of renal arterial blood flow by Doppler ultrasonography, neurohormonal parameters and human atrial natriuretic peptide (hANP) in chronic liver disease. These parameters were measured in 45 patients with chronic liver disease (15 patients with chronic hepatitis and 30 patients with liver cirrhosis) and 16 healthy subjects. Patients with liver cirrhosis were classified into nine patients with ascites responsive to the conventional treatment, one with refractory ascites and 20 without ascites. Renal arterial velocity was obtained from measurements in the main renal artery (RA) in the cortex. The resistive index (RI) (=(peak systolic velocity−minimum diastolic velocity)/peak systolic velocity) in different areas of the kidney was significantly higher in patients with liver cirrhosis than in patients with chronic hepatitis and healthy subjects. Among cirrhotic patients, RI was higher in patients with ascites than in those without ascites. The RI decreased from the hilum of the kidney to the outer parenchyma in both patients with chronic liver disease and healthy subjects. Neurohormonal parameters tended to be higher but this difference was not significant in patients with liver cirrhosis, especially in those with ascites. Serum hANP levels were positively correlated with main renal arterial RI ( r=0.728, P<0.5), segmental arterial RI ( r=0.729, P<0.05), interlobar arterial RI ( r=0.919, P=0.001) and interlobular aterial RI ( r=0.720, P<0.05) in cirrhotic patients with ascites but no correlation was found with the RI of the peripheral artery in the cortex. On the other hand, in patients without ascites, serum hANP was positively correlated with renal arterial RI, even with the RI of the cortical artery. In addition to measurement of hANP, measurement of renal arterial RI from the hilum to the cortical artery of the kidney by Doppler ultrasonography is beneficial for differentiating stage between with and without ascites in liver cirrhosis and for evaluating changes in systemic and renal hemodynamics. Neurohormonal parameters and hANP were related to the presence or absence of liver cirrhosis. The serum level of hANP is useful for estimating hyperdynamic circulation in liver cirrhosis.