LAUSR

BackgroundsA two-stage procedure involving endoscopic retrograde cholangiopancreatography (ERCP), followed by cholecystectomy, is one of the primary treatments of concomitant gallstones and choledocholithiasis. However, negative findings on ERCP and migrating gallstones after cholecystectomy are major concerns. This study aimed to identify the prevalence of unnecessary ERCP and to develop and validate a predictive nomogram using preoperative factors in patients who underwent a two-stage procedure.MethodsConsecutive 931 patients were treated with the two-stage procedure for evident gallstones and suspected choledocholithiasis. After the cholecystectomy, a cholangiogram was performed to confirm the absence of the migrating gallstones. The patients were divided into derivation (n = 652) and validation (n = 279) cohorts.ResultsA total of 26.5% (247/931) patients had unnecessary ERCP (negative choledocholithiasis, 14.6%; migrating gallstones, 11.9%). No stones on images (P < 0.001), total bilirubin < 1.2 mg/dL (P = 0.006), and common bile duct diameter < 8.0 mm (P = 0.004) were independent factors associated with negative finding on ERCP with a validated nomogram area under the curve (AUC) of 0.72 (95% confidence interval [CI] 0.64–0.80). For migrating gallstones after cholecystectomy, radiolucent gallstones (P < 0.001), gallstone size ≤ 6.4 mm (P = 0.001), cystic duct stones (P < 0.001), gallbladder wall thickness ≥ 3.2 mm (P = 0.003), and low-lying cystic duct (P < 0.001) were independent factors with a validated nomogram AUC of 0.77 (95% CI 0.68–0.87).ConclusionsAbout one fourth of the patients may have unnecessary ERCP in the two-stage procedure. Based on our nomogram using preoperative factors, high-risk patients who are more likely to perform unnecessary ERCP could be considered for the one-stage procedure.