Reliability of the estimation of total hepatic blood flow by Doppler ultrasound in patients with cirrhotic portal hypertension.

Background & Aims: Hepatic blood flow (HBF) is best estimated by the Fick’s method during indocyanine green constant infusion (ICG-HBF) on hepatic vein catheterization. We investigated the consistency and agreement of HBF measured by Doppler ultrasound (US-HBF) as compared with ICG-HBF in portal hypertensive patients with cirrhosis. Methods: In 50 patients observed for HVPG measurement (56% compensated; Child score 7±2; HVPG 16.6±6.0mmHg; varices in 75%) US-HBF (Sequoia-512-Acuson; 4.5–7MHz convex probe; US-HBF=hepatic artery blood flow+portal vein blood flow) and ICG-HBF (Fick’s method after an equilibration period of at least 45min of ICG bolus of 5mg+constant rate infusion of 0.2mg/min). Intraclass correlation coefficient (ICC) for consistency and absolute agreement between US-HBF and ICG-HBF were calculated. Results: Mean ICG-HBF and US-HBF were similar, being respectively 1004±543ml/min and 994±494ml/min (p= 0.661 vs. ICG-HBF). However, results in individual patients disclosed marked differences between the two methods (386±415ml/min) and showed only moderate consistency (ICC 0.456; p<0.0001), absolute agreement (ICC 0.461; p<0.0001) and linear correlation (R=0.464; p<0.0001). The discrepancy between the two methods was maximal in patients with poor liver function, high HBF by any technique and more arterialized liver circulation. Hepatic artery blood flow ⩾40% of US-HBF indicated, with 90% specificity, a discrepancy ⩾20% between US-HBF and ICG-HBF. Conclusions: HBF estimations by Doppler-ultrasound and ICG are significantly correlated, but their discrepancy in individual cases is high. Estimation of HBF by Doppler-US should be considered unreliable in patients with poor hepatic function and large liver arterialization. [ABSTRACT FROM AUTHOR]