Objectives To explore the optimal surgical timing of laparoscopic cholecystectomy for patients with acute calculous cholecystitis complicated with mild pancreatitis based on a design of the prospective study, and to establish a predictive model for surgical timing.

Methods A total of 100 patients with laparoscopic cholecystectomy for acute calculous cholecystitis complicated with mild pancreatitis from May 2020 to November 2022 were selected as the research objects. Among them, 20 cases underwent laparoscopic cholecystectomy within 72 hours after hospital admission were assigned to early surgery group, and 80 cases underwent surgery at 72 hours after hospital admission were assigned to late surgery group. The basic clinical materials of patients in both groups were recorded, and the surgery related indicators and total hospital stay were compared. Taking the group as the dependent variable, single factor analysis and multi-factor Logistic regression analysis were used to screen out factors that may have impacts on surgical timing decision, and independent risk factors that may have impacts on surgical timing were identified. A receiver operating characteristic (ROC) curve was drawn, a surgical timing prediction model was established, and the discriminant cut-off points of the model were calculated.

Results The median time for surgery in the early surgery group was on the third day of hospitalization, while it was on the seventh day in the late surgery group, and there was a significant difference between two groups (P < 0.05). The median hospital stay in the early surgery group was 7 days, while it was 11 days in the late surgery group, and there was a significant difference between two groups (P < 0.05). There were significant differences in total bilirubin, aspartate aminotransferase (AST), glutamate pyruvate aminotransferase (ALT) and blood amylase between the two groups (P < 0.05). Multivariate Logistic regression analysis showed that total bilirubin (OR=0.24, 95%CI, 0.068 to 0.988, P=0.048), AST (OR=0.19, 95%CI, 0.042 to 0.882, P=0.034) and blood amylase (OR=0.26, 95%CI, 0.068 to 0.988, P=0.048) were the determining factors for the timing of laparoscopic cholecystectomy for acute calculous cholecystitis complicated with mild pancreatitis; after collinearity diagnosis, the collinearity relationships between the three indexes were excludedvariance inflation factor (VIF) < 2. A predictive model was established and the ROC curve was drawn. Kappa consistency test showed that the model had good discriminationarea under the curve (AUC)=0.80 and good consistency (Kappa value=0.40), indicating that the predictive model can better determine the timing of laparoscopic cholecystectomy for patients with acute calculous cholecystitis complicated with mild pancreatitis.

Conclusion It is recommended that patients with acute calculous cholecystitis complicated with mild pancreatitis should not simply pursue early surgery, but exclude the potential factors for severe exacerbation of mild pancreatitis before surgery. It is meaningful to determine whether the patients have biliary pancreatitis, hyperlipidemic pancreatitis, and a BISAP score of no less than 48 hours after admission before surgery to assess the potential risk of severe exacerbation of mild pancreatitis. Serum amylase, total bilirubin and AST can be used as protective factors for early laparoscopic cholecystectomy in patients with mild acute pancreatitis.