Abstract: Objective To investigate the efficacy and safety of choledochoscopic dual-frequency dual-pulse（DFDP） laser lithotripsy for the treatment of postoperative biliary tract stone remnants.Methods A total of 112 patients with residual stones after biliary tract surgery admitted from August 2014 to December 2022 were divided into two groups according to treatment modalities.The observation group (n=63) received choledochoscopic DFDP laser lithotripsy,while the control group (n=49) underwent conventional basket extraction.We compared stone clearance rates,complications,perioperative indicators,and surgical outcomes between the two groups.ResultsThe stone extraction rate of the observation group was significantly higher than that of the control group（95.2% vs.73.5% ，P＜0.05）,and the difference was statistically significant.Compared with the control group,the observation group had fewer average stone removals（two times vs three times，P＜0.05）and shorter average operation time(22.8 min vs.24.1 min，P＜0.05）.The postoperative gamma glutamyl transferase (GGT) level of the observation group was lower than that of the control group（63 U/L vs.109.0 U/L，95%CI:-63～-9，P＜0.05）,and the degree of postoperative GGT reduction in the observation group was greater than that in the control group（-40.8 U/L vs.-28.0 U/L，95%CI：-23.5～-0.8，P＜0.05）,the differences were both statistically significant.The observation group demonstrated a statistically significant reduction in complication rate compared to control group（1.6% vs.14.2%，P＜0.05）.Conclusion DFDP laser lithotripsy under choledochoscopy for the treatment of residual stones after biliary surgery has the advantages of high efficiency,safety and convenience.

Key words: dual-frequency dual-pulse laser, choledochoscopy, postoperative biliary residual stones, lithotripsy