Preduodenal portal vein--a cause of intestinal obstruction?

A preduodenal position of the portal vein is a rare anomaly reported in 52 cases in the literature. Two additional cases are reported here. In 54% of the cases of preduodenal portal vein (PPV) was combined with high intestinal obstruction and in one half of these cases PPV was considered obstructive. A critical review of these cases given the impression that obstructive PPV could well be a misinterpretation of the obstructive situation and the existence of obstructive PPV is doubted.