Anatomic variation: absence of portal vein bifurcation

Purpose To describe in CT scan the absence of a portal vein bifurcation. Methods We described the contrast-enhanced CT scan appearance of an absence of portal vein bifurcation in an "asymptomatic" 39 year old woman. Results It was a single intrahepatic portal vein which crossed the entire liver parenchyma from the right to the left and with a gradually decreasing diameter. The vascularization of the hepatic parenchyma was not ensured by third order branches, but directly made by second order ramifications which were regularly originated from the single IHPV along its course. This unusual portal vein mimicking a left portal vein agenesis, appeared in fact to be more in relation with a right portal vein agenesis. Distribution of hepatic veins and hepatic volume was normal. Conclusion This very rare anatomic variation is easily detected on CT scan and appears important to describe for surgeon and interventional radiologists.