Prepancreatic postduodenal portal vein: a new hypothesis for the development of the portal venous system.

The prepancreatic postduodenal portal vein (PPPV) is an unusual anomaly, having been reported in only 11 cases including ours. Although its incidence is rare, this anomaly can cause intraoperative complications such as hemorrhage from the abnormal vein. Radiologists therefore need to be aware of this anomaly and, when identifi ed, report it to surgeons before surgery. Here we report two cases of PPPV and present a new hypothesis for development of the portal venous system.