Renovascular resistance assessed by color Doppler ultrasonography in patients with chronic liver diseases

BACKGROUND AND AIMS: Renal arterial vasoconstriction is known to be related to renal hemodynamic derangement in patients with liver cirrhosis. Using color Doppler ultrasonography in patients with chronic liver diseases, abnormal resistance in the renal artery was examined non-invasively both cross-sectionally and longitudinally to clarify the relationship between renal vascular resistance and liver function to neurohumoral factors. METHODS: The study comprised 118 patients with cirrhosis, 23 patients with chronic hepatitis, and 35 healthy controls. Pulsatility and resistive indices that were derived from renal artery velocity analysis were used as parameters of renal arterial resistance. RESULTS: Both the pulsatility and resistive indices were significantly higher in cirrhotic patients (1.29 +/- 0.37, P < 0.001 and 0.69 +/- 0.07, P < 0.001, respectively) compared to controls (1.00 +/- 0.12 and 0.62 +/- 0.05, respectively) and compared to patients with chronic hepatitis (0.97 +/- 0.13 and 0.60 +/- 0.05, respectively). Both indices showed significant correlation with increased Child-Pugh grade. Each correlated significantly with plasma renin activity and plasma aldosterone and norepinephrine levels. Multivariate analysis of the relationship between neurohumoral factors and renal arterial resistance disclosed that plasma renin activity was a significant independent predictor. The longitudinal change in pulsatility index, resistive index and neurohumoral factors were examined in the cirrhotic patients who were followed-up for longer than 6 months. Pulsatility and resistive indices increased according to the deterioration of liver function and the changes in both indices were closely related to the change in plasma renin activity. CONCLUSIONS: Pulsatility index and resistive index as measured by color Doppler ultrasonography were closely related to the severity of cirrhosis and to the levels of neurohumoral factors, especially plasma renin activity, in this cross-sectional and longitudinal study. Therefore, they are useful indices for assessing renal hemodynamics in patients with cirrhosis.