RT Journal Article SR Electronic T1 Optimal timing of cholecystectomy after necrotising biliary pancreatitis JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP gutjnl-2021-324239 DO 10.1136/gutjnl-2021-324239 A1 Nora D Hallensleben A1 Hester C Timmerhuis A1 Robbert A Hollemans A1 Sabrina Pocornie A1 Janneke van Grinsven A1 Sandra van Brunschot A1 Olaf J Bakker A1 Rogier van der Sluijs A1 Matthijs P Schwartz A1 Peter van Duijvendijk A1 Tessa Römkens A1 Martijn W J Stommel A1 Robert C Verdonk A1 Marc G Besselink A1 Stefan A W Bouwense A1 Thomas L Bollen A1 Hjalmar C van Santvoort A1 Marco J Bruno A1 , YR 2021 UL http://gut.bmj.com/content/early/2021/07/15/gutjnl-2021-324239.abstract AB Objective Following an episode of acute biliary pancreatitis, cholecystectomy is advised to prevent recurrent biliary events. There is limited evidence regarding the optimal timing and safety of cholecystectomy in patients with necrotising biliary pancreatitis.Design A post hoc analysis of a multicentre prospective cohort. Patients with biliary pancreatitis and a CT severity score of three or more were included in 27 Dutch hospitals between 2005 and 2014. Primary outcome was the optimal timing of cholecystectomy in patients with necrotising biliary pancreatitis, defined as: the optimal point in time with the lowest risk of recurrent biliary events and the lowest risk of complications of cholecystectomy. Secondary outcomes were the number of recurrent biliary events, periprocedural complications of cholecystectomy and the protective value of endoscopic sphincterotomy for the recurrence of biliary events.Results Overall, 248 patients were included in the analysis. Cholecystectomy was performed in 191 patients (77%) at a median of 103 days (P25–P75: 46–222) after discharge. Infected necrosis after cholecystectomy occurred in four (2%) patients with persistent peripancreatic collections. Before cholecystectomy, 66 patients (27%) developed biliary events. The risk of overall recurrent biliary events prior to cholecystectomy was significantly lower before 10 weeks after discharge (risk ratio 0.49 (95% CI 0.27 to 0.90); p=0.02). The risk of recurrent pancreatitis before cholecystectomy was significantly lower before 8 weeks after discharge (risk ratio 0.14 (95% CI 0.02 to 1.0); p=0.02). The complication rate of cholecystectomy did not decrease over time. Endoscopic sphincterotomy did not reduce the risk of recurrent biliary events (OR 1.40 (95% CI 0.74 to 2.83)).Conclusion The optimal timing of cholecystectomy after necrotising biliary pancreatitis, in the absence of peripancreatic collections, is within 8 weeks after discharge.Data are available upon reasonable request from the corresponding author.