The critical view of safety in laparoscopic cholecystectomy is optimized by exposing the inner layer of the subserosal layer.

During laparoscopic cholecystectomy (LC), misidentification of the cystic duct, which causes major bile duct injuries, can result from wrong or incomplete dissection of Calot's triangle. Therefore, the critical view of safety has been accepted as a safe method for gaining a sufficient view of Calot's triangle before transecting the cystic duct. However, even in cases without aberrant anatomy of the bile duct, bile duct injury can occur by a wrong approach to a critical view of safety. Additionally, in cases of badly inflamed gallbladders, it is often hard to achieve a critical view of safety, because Calot's triangle is often solid and cannot be expanded. In our standardized procedure, which is based on exposing the inner layer of the subserosal layer (the ss-i layer), the critical view of safety can be safely achieved. We have safely performed LC, using our standardized procedure, for many cases with cholecystitis with highly inflamed gallbladders. In this article, focusing especially on prevention of bile duct injuries, we present our standardized procedure to achieve the critical view of safety along with histological findings.