Hepatic hilum plane is the hepatoduodenal serosa plane that extends from the base of the liver IVa segment down to the first segment of the gallbladder triangle.~During the operation, first pulling the gallbladder to the head side, using the separating forceps to slide down horizontally from the hilum (the basement of hepatic segment Ⅳ), and along the serous of hepatoduodenal ligament, that is so called hilum plane.~It forms a neck-shoulder structure when the hilar plane meets the tent-like hepatobiliary triangle. the serosa of hepatobiliary triangle was dissected on the neck area and ventral side of hilar plane, and the serosa of posterior triangle of the gallbladder was also cutted on the same extension line . In this process, the type and orientation of RS, the relationship between the plane of the RS sulcus and the plane of the hilar plane were also recorded and compared with hilum plane.
RS and the RS plane are important anatomical markers in laparoscopic cholecystectomy. However, there are many variations in the shape and orientation of the RS, and the RS plane is an imaginary plane, which can be misjudged by different surgeons. The purpose of this study is to introduce a more intuitive anatomical marker and anatomical plane, hilum plane, and discuss the application value of hilum plane in laparoscopic biliary surgery by comparing it with RS and RS plane.