The afferent circulation of the liver in patients with primary hepatocellular carcinoma

The data on the afferent circulation of the liver, in patients with primary hepatocellular carcinoma, are controversial or non-existent.

The authors measured hepatic arterial and portal venous flow intra-operatively by transit time ultrasonic volume flowmetry.

In patients with primary hepatocellular carcinoma, the hepatic artery flow increased to 0.55 +/- 0.21 l, as compared with the control value of 0.37 +/- 102 l/min (p < 0.01). The portal venous flow decreased from 0.61 +/- 0.212 l/min to 0.47 +/- 0.203 l/min p < 0.01). Owing to the opposite changes in the afferent circulation, the total hepatic blood flow did not change significantly. The ratio of hepatic arterial flow to portal vein flow increased to 1.239 +/- 0.246 in patients with hepatocellular carcinoma, which is twice the basic control value (0.66 +/- 0.259 l/min). After resection, this ratio showed virtually no change. The surgical intervention, that is resection of the liver, did not significantly alter hepatic artery and portal venous flow, although total hepatic blood flow decreased significantly (p < 0.01). The pronounced increase in the ratio of hepatic arterial flow may be attributed to the decrease in portal venous flow caused by the primary hepatocellular carcinoma. The decrease in venous flow can most probably be explained by compression and infiltration of the intrahepatic branches of the portal vein. As we pointed out, the decrease in portal venous circulation leads to an increase in hepatic arterial flow.

On the basis of our initial results, it seems probable that the ratio of the two circulations represents a diagnostic tool for the altered circulation in patients with hepatocellular carcinoma. The significance of this phenomena is not yet quite clear, but a review of the literature shows that similar observations have not been reported. In practical terms this phenomenon may be useful from the point of view of US and Doppler US diagnosis, e.g. in the case of a hypo-echoic or hyperechoir, mass in the liver, increased blood flow in the hepatic, artery, and decreased portal venous flow, a malignant liver tumor is virtually certain. The authors hypothesise that any pathology in the liver may lead to a primary decrease in PVF and a subsequent increase in HAF.