Clinical Impact of Residual Gallbladder Neck–Cystic Duct Stones on Postoperative Outcomes in Acute Cholecystitis: A Retrospective Study

Background: The clinical significance of residual gallstones (RGSs) in the gallbladder neck–cystic duct after cholecystectomy for acute cholecystitis (AC) remains unclear. This study aimed to evaluate the association between RGSs and postoperative outcomes, including the development of common bile duct stones (CBDSs) in AC. Materials and Methods: We retrospectively analyzed 272 consecutive patients who underwent cholecystectomy for AC at our institution between April 2016 and December 2025. RGSs in the gallbladder neck–cystic duct were identified based on imaging findings and surgical records. The postoperative outcomes and their associated risk factors were evaluated. Results: RGSs after surgery were identified in 24 (8.8%) of 272 patients. Postoperative complications, length of hospital stay, and the incidence of remnant cholecystitis did not differ significantly between the RGS-positive and -negative groups. Postoperative CBDSs occurred significantly more frequently in the RGS-positive group than the RGS-negative group (37.5% versus 3.2%, P < .001). Multivariate analysis identified RGS positivity as the only independent risk factor for CBDS after cholecystectomy ( P < .001). All symptomatic CBDSs occurred within 6 months after surgery. Among patients with RGSs, stone location and volume showed limited predictive performance for CBDS. All postoperative CBDSs were successfully treated endoscopically, and no patient required reoperation. Conclusions: RGSs in the gallbladder neck–cystic duct are associated with an increased risk of postoperative CBDS in patients with AC. When feasible, intraoperative stone removal should be considered; however, postoperative endoscopic management represents an effective alternative when stone removal is technically challenging.