A prospective experimental study of liver fibrosis with ultrasound and its correlation with hepatic reserve function and hemodynamics

BACKGROUND Progressive hepatic fibrosis is the eventual cause of liver cirrhosis. Doppler ultrasound has been used to detect hemodynamic changes that are known to be present during the pre-cirrhotic stages of hepatic fibrogenesis. However, the relationship between the Doppler ultrasound parameters and the impairment of the liver function has not been fully investigated. The purpose of this study was to explore the hepatic function reserve and its relationship with the hepatic hemodynamics in a rabbit model of liver fibrosis using Doppler ultrasound. METHODS A prospective study was performed. Sixty healthy New Zealand rabbits were included in this study. Eleven of them served as controls and were normally fed and provided with water drink; the rest of 49 rabbits that served as fibrosis group were normally fed but provided with 1.2 g/L of thioacetamide to create liver fibrosis model. Doppler measurements were performed in the portal trunk, proper hepatic artery and proper splenic artery. The hepatic circulation index (HCI) was calculated. Hepatic function reverse was evaluated by measuring the indocyanine green clearance and retention rate at 15 min (ICG R15) test. Portal venous pressure (PVP) was measured using the portal vein punctuation equipment. RESULTS HCI was significantly decreased and PVP increased in the advanced fibrotic stage (F4) compared to mild and moderate fibrotic stage (F1-3), respectively (p<0.05). PVP and ICG R15 in the fibrotic group were significantly higher than that in the control group (ICG: 0.209±0.086 vs. 0.093±0.023, p<0.01). Within the fibrotic groups, PVP was higher in advanced fibrotic stage (F4) than those in mild (F1-2) or moderate (F3) fibrotic stages (p<0.05). Both HCI and PVP correlated well with ICG R15 (r = -0.890, and r = 0.780, p <0.01). CONCLUSIONS Hepatic function reserve closely relates to the hepatic hemodynamics in the rabbit model of liver fibrosis. Doppler Ultrasound could be reliably used to assess the hepatic function reserve and hemodynamic changes in different stages of liver fibrosis.