ObjectiveTo explore technical essentials and safety of laparoscopic cholecystectomy (LC) guided by gallbladder ampulla localization on an imaginary clock for cholecystitis.MethodsA retrospective study of 8 707 continuous patients with mild cholecystitis who underwent LC from July 1998 to February 2018 at a single institution was conducted. Among them, 3 168 patients were treated by the traditional LC from July 1998 to February 2007 (a traditional LC group), 5 539 patients were treated by the LC with the guidance of the gallbladder ampulla localization on an imaginary clock from March 2007 to February 2018 (a gallbladder ampulla localization group). The conversion to open surgery, bile duct injury, return to the operating room due to postoperative massive abdominal bleeding, bile leakage without bile duct injury, operative time, intraoperative blood loss, and postoperative hospital stays were compared between the traditional LC group and the gallbladder ampulla localization group.ResultsThere were no significant differences in the gender, age, course of disease, and type of cholecystitis between these two groups (P>0.050). The rates of conversion to open surgery, bile duct injury, return to the operating room due to postoperative massive abdominal bleeding, bile leakage without bile duct injury and the operative time, intraoperative blood loss and postoperative hospital stays in the traditional LC group were 3.00% (95/3 168), 0.13% (4/3 168), 0.09% (3/3 168), 0.03% (1/3 168), (43.6±12.6) min, (18.7±3.3) mL, (3.6±2.7) d, respectively, which in the gallbladder ampulla localization group were 0 (0/5 539), 0 (0/5 539), 0 (0/5 539), 0 (0/5 539), (32.2±10.5) min, (12.4±3.5) mL, (3.5±2.8) d, respectively. The differences of conversion to open surgery, bile duct injury, return to the operating room due to postoperative massive abdominal bleeding rates, and the operative time and intraoperative blood loss were statistically significant between these two groups (P<0.050). The differences of the bile leakage without bile duct injury rate and postoperative hospital stays were not statistically significant between the two groups (P>0.050).ConclusionThis study shows that gallbladder ampulla localization on an imaginary clock is useful for ductal identification so as to reduce bile duct injury and improve safety of LC in case of no conversion to open surgery.