Vascular and biliary variants in the liver: implications for liver surgery.

Accurate preoperative assessment of the hepatic vascular and biliary anatomy is essential to ensure safe and successful hepatic surgery. Such surgical procedures range from the more complex, like tumor resection and partial hepatectomy for living donor liver transplantation, to others performed more routinely, like laparoscopic cholecystectomy. Modern noninvasive diagnostic imaging techniques, such as multidetector computed tomography (CT) and magnetic resonance (MR) imaging performed with liver-specific contrast agents with biliary excretion, have replaced conventional angiography and endoscopic cholangiography for evaluation of the hepatic vascular and biliary anatomy. These techniques help determine the best hepatectomy plane and help identify patients in whom additional surgical steps will be required. Preoperative knowledge of hepatic vascular and biliary anatomic variants is mandatory for surgical planning and to help reduce postoperative complications. Multidetector CT and MR imaging, with the added value of image postprocessing, allow accurate identification of areas at risk for venous congestion or devascularization. This information may influence surgical planning with regard to the extent of hepatic resection or the need for vascular reconstruction. (c) RSNA, 2008