Anatomy and variation of the portal vein

Objective: To reconstruct 3-dimentional portal vein and hepatic veins by computed tomography arterial portography(CTAP) and determine the variations of the portal vein and hepatic veins at physiological state. Methods: Livers of 150 patients were continuously scaned at the intrahepatic portal vein and hepatic vein phases after injecting contrast medium into superior mesenteric artery through catheter. The variations of the portal vein were observed after reconstructing 3-dimentional portal vein and hepatic veins. Results: There were variations of 25 portal veins in 150 patients examined. 12 cases (8.0%) showed trifurcation, 10 cases (6.7%) showed a right posterior branch arising from the main portal vein first and then the right anterior and left portal vein originated from the ascending main portal vein, 1 case (0.7%) absent the horizontal segment of the left portal vein and 2 cases (1.3%) absent right portal vein. The remaining 125(83.3%) patients appeared normal distribution of the portal vein. Conclusions:Reconstruction and type analysis of 3-dimentional portal vein is significant for determining operational methods in clinic.