FLOW REVERSAL IN THE RIGHT ANTERIOR BRANCH OF THE PORTAL-VEIN - BICOLOR PORTAL-VEIN COLOR DOPPLER ANALYSIS

The purpose of this study is to describe a phenomenon of bidirectional flow, ''bicolor portal vein'' (BPV), within the right anterior branch of the portal vein (RAPV), with color Doppler imaging (CDI). We prosp ectively studied with CDI the intrahepatic portal vein and its branche s in 316 consecutive patients in search of areas of nonlaminar now wit hin the RAPV. Forty patients were excluded from the study due to varie d conditions that precluded an accurate CDI study. A prospective desig n allowed us to record the frequency of appearance, systematically mea sure a set of parameters in each patient, and establish different grou ps for comparison. We found an area of BPV within the RAPV in six pati ents. Five of them had a history of liver disease (8.2% of the patient s with known liver disease). The BPV was consistently portrayed as a w ell-defined blue oval-shaped area of flow reversal attached to the med ial side of the RAPV immediately before its bifurcation, suggesting a rotary motion of blood. All six patients presented a transverse diamet er of the RAPV significantly larger than the rest of the patients (p < 0.05). Furthermore, blood flow measurements within the RAPV of the si x patients with BPV were found to be significantly higher when compare d with the rest of the patients (<0.05). Knowledge of the possible pre sence of a BPV within the RAPV can prevent diagnostic confusion with r eversal of flow, a truly pathologic condition related to liver disease . (C) 1995 John Wiley and Sons, Inc.