Abstract: Objective This study was conducted to investigate impact of activation of bile neutrophil extracellular trap network(NETN) on relapse of patients with choledocholithiasis after endoscopic retrograde cholangiopancreatography (ERCP) treatment. Methods 120 patients with choledocholithiasis were encountered in our hospital between January 2020 and December 2021, all patients underwent ERCP for removal of bile stones and were followed-up for 18 months. During ERCP, bile was collected for detection of myeloperoxidase (MPO), neutrophil elastase (NE) and citrullinated histone H3(CitH3) levels. Multivariate Logistic regression analysis was used to reveal risk factors affecting recurrence of common bile duct stones after surgery. Results The ERCP was completed successfully in our series, and by 18 months after operation, bile stone recurred in 21 cases (17.5%); baseline numbers of duodenal papilla diverticulum and common bile duct stones and incidences of mechanical lithotripsy in patients with recurred stones were 28.6%,(2.6±0.7) and 57.1%, all significantly higher than 5.0%, (1.9±0.8) and 28.3%(P<0.05), peripheral white blood cell count and neutrophil ratio were (7.7±2.0)×10⁹/L and (83.8±8.7)%, much higher than [(6.2±2.1)×10⁹/L and (70.5±6.2)%, respectively, P<0.05], and serum C-reactive protein, total serum bilirubin and carbohydrate antigen 199levels were (37.2±4.7)mg/L,(65.4±14.3)μmol/L and (152.9±37.4)kU/L, all significantly higher than [(8.8±2.2)mg/L, (16.7±4.2)μmol/L and (17.2±2.9)kU/L, respectively, P<0.05] in patients without stone recurrence; bile MPO, NE and CitH3 levels in patients with recurred stones were (34.7±5.4)U/L, (22.4±5.0)ng/L and (0.34±0.09)μg/L, all much higher than [(18.1±2.9)U/L, (14.5±2.7)ng/L and (0.12±0.05)μg/L, respectively, P<0.05] in patients without recurred stones; multivariate Logistic regression analysis showed that baseline concurrent duodenal papilla diverticulum, common bile duct stone numbers, mechanical lithotripsy, as well as bile MPO, NE and CitH3 levels were all the risk factors for recurrence of bile stones after ERCP (P<0.05). Conclusion Activation of bile NETN could be involved in the formation of bile stones, and detection of its markers might be helpful in predicting recurrence of bile duct stones after operation.

Key words: Choledocholithiasis, Endoscopic retrograde cholangiopancreatography, Neutrophil extracellular trap network, Recurrence