Portal blood flow via the peribiliary vascular plexus demonstrated by contrast‐enhanced ultrasonography with Sonazoid

Abstract

We report two cases in which portal blood flow via the peribiliary vascular plexus (PBP) was clearly demonstrated using contrast-enhanced intra-operative ultrasonography (CE-IOUS). Two patients who underwent hemihepatectomies were investigated using CE-IOUS. Before injection of the contrast medium, both the hepatic arterial and portal venous flows of the hemiliver to be resected were interrupted by ligating those corresponding vessels at the hepatic hilum. Subsequently, the perfluorobutane microbubbles were injected intravenously. In the early vascular phase, a remarkable intermittent flow was visualized in the lumen of the portal branches whose inflows were interrupted. The flow of the portal vein then disappeared as a result of ligating the hepatic duct concomitantly with the surrounding connective tissue. We considered that the portal venous flow appearing under the condition of total disruption of original inflow was supplied from the hepatic artery through the PBP. This is the first report of blood flow via the PBP in human liver visualized by dynamic image study.