The role of duplex-doppler ultrasonography in the diagnosis of renal dysfunction and hepatorenal syndrome in patients with liver cirrhosis.

BACKGROUND/AIMS: Kidney dysfunction commonly develops in patients with liver cirrhosis. Renal failure develops due to renal vascular constriction and can be present weeks or even months before clinical signs or increased levels of blood urea nitrogen or serum creatinine concentrations become detectible. The objective of this study was to analyze the value of renal interlobar arterial resistance index, measured by duplex-Doppler ultrasonography for detecting early impairment of renal function in patients with liver cirrhosis and its possible use in detecting a subgroup of patients with a higher risk of developing hepatorenal syndrome.

METHODOLOGY: The patients were divided into three groups: patients with liver cirrhosis and normal renal function (n=31), patients with liver cirrhosis and renal failure but without hepatorenal syndrome criteria (n=9), and patients with hepatorenal syndrome (n=6). The interlobar arterial resistance index was estimated with duplex Doppler ultrasonography, and liver and renal function tests were measured in all patients.

RESULTS: The average value of interlobar arterial resistance index in patients with hepatorenal syndrome (0.74+/-0.01) was statistically significantly higher than interlobar arterial resistance index values measured in liver cirrhosis patients without the signs of azotemia (0.65+/-0.03) or in those with liver cirrhosis and kidney dysfunction, but without hepatorenal syndrome (0.67+/-0.01). In all patients with hepatorenal syndrome the value of interlobar arterial resistance index was over 0.70. In the group of patients with liver cirrhosis and kidney dysfunction, but without hepatorenal syndrome, interlobar arterial resistance index was below 0.70 in seven, whereas in the remaining two interlobar arterial resistance index was above 0.70. In those patients renal dysfunction displayed a progressive form and hepatorenal syndrome developed.

CONCLUSIONS: Duplex-Doppler ultrasound of intralobar arteries is a simple, effective and non-invasive method which enables the early detection of renal hemodynamic disturbances in patients with liver cirrhosis even before renal dysfunction becomes clinically evident. It also makes possible the identification of a subgroup of patients with liver cirrhosis who are at higher risks for developing hepatorenal syndrome.