Therapeutic Thulium laser usually use in urology [1]. But now the indications for applying a new generation thulium laser in endoscopy are expanding [2]. In this case, we report one of the first experience of successful management of choledocholithiasis using cholangioscopy-assisted thulium laser lithotripsy.

A 68-year-old female showed typical symptoms of progressive jaundice. Chronic calculous cholecystitis was known from the medical history. Laboratory tests were consistent with obstructive jaundice: elevated hepatic enzymes (total bilirubin-207 mg/dL, direct bilirubin 138 mg/dL, ALT - 254 IU/L, AST - 353 IU/L). Transabdominal ultrasound (TUS) showed dilated intrahepatic and extrahepatic bile ducts with a 20 mm stuck stone in the common bile duct (CBD). MRI showed chronic calculous cholecystitis and signs of moderate biliary hypertension with obstruction at the middle and lower thirds of the CBD (fig.1.) We also performed EUS which showed the biliary hypertension and the bile stone (>15 mm) at the level of the confluence of the cystic duct (fig.2.) Standard ERCP-lithoextraction with balloon sweep and basket retrieval was failed. Then our treatment plan included performing a repeat ERCP to visualize the biliary tree and facilitate cholangiscopy-assisted thulium laser lithotripsy to break down the stone and remove the fragments.

 We performed cholangioscopy-assisted lithotripsy for a fixed CBD stone using a superpulse thulium laser (power: 30 W, pulse energy: 30 J, frequency: 1 Hz, fiber diameter: 365 μm, Urolase+Premium). (fig.3,4.) The design of thulium laser minimizes retropulsion compared to other lithotripsy lasers. The selected pulse frequency effectively fragments stones into small pieces, including sand-sized particles (fig.5.) The thulium laser features an innovative tissue sensor function that enhances the safety and efficacy of laser treatments by distinguishing between hard and soft tissues. During lithotripsy, this technology automatically halts laser emission when aimed at the mucosa, thereby reducing the risk of tissue damage. Following the lithotripsy procedure, all fragments were successfully removed from the CBD (fig.6.) The procedure was completed without any adverse events or complications, and the patient was subsequently discharged.

This case report aimed to explore the efficacy and safety of new generation thulium laser (fig.7.) Thulium laser lithotripsy can be applied in endoscopic management of biliary stones during ERCP to fragment large stones that cannot be removed by standard ERCP-techniques. There are no any published cases of in vivo experience using the thulium laser for bile stone fragmentation. Further research and clinical trials will help to refine thulium laser use and establish best practices for optimal patient outcomes in the management of bile duct stones.