[Anatomical variations of vessels and bile ducts in hepatobiliary surgery : What must be considered in gallbladder and liver surgery?].

Anatomical variations of both the vascular structures of the liver and gallbladder as well as the bile ducts, are very common. Detailed knowledge of the different courses of these vessels and ducts as well as their topographical relationships to one another, is essential in hepatobiliary procedures and surgery involving the upper gastrointestinal tract. Whenever possible, these variations should be identified preoperatively. This is best achieved through contrast-enhanced computed tomography (CT) with both portal venous and arterial phases, and for bile ducts, additionally via magnetic resonance imaging (MRI)/MRCP with liver-specific contrast agents. In smaller procedures involving the hepatic hilum (such as lymph node dissection or cholecystectomy), cross-sectional imaging is not routinely available. In these cases, both the awareness of anatomical variations and the ability to use intraoperative tools (such as ICG fluorescence or cholangiography) are crucial. Although bile duct injuries during cholecystectomy are overall rare (0.2-0.8%), they are frequently associated with vascular damage (up to 61%) and have a significant impact on postoperative morbidity.