Removal of lollipop-shaped stent-stone complex using direct-vision laser lithotripsy

Long-term retention of biliary plastic stents (PS) can lead to a rare complication: the formation of a lollipop-shaped stent-stone complex (LSSC) [1], where stones encase the proximal end of the stent, making endoscopic removal technically difficult. We report a case of successful LSSC removal using peroral cholangioscopy (POCS)-guided frequency-doubled dual pulse Nd:YAG (FREDDY) laser lithotripsy.

A 72-year-old man, previously diagnosed with IgG4-related sclerosing cholangitis, underwent biliary and pancreatic PS placement three years prior to alleviate obstructive jaundice ([Fig. 1]), followed by corticosteroid therapy. He was lost to follow-up. One month before admission, he presented with jaundice and fever. Emergency ERCP showed resolution of the biliary stricture but revealed a retained LSSC in the common bile duct (CBD). Removal attempts using standard tools failed, fracturing the stent at the duodenal lumen. A supplementary PS was placed to ensure drainage ([Fig. 2]). Following stabilization, repeat ERCP was performed using POCS-guided laser lithotripsy. The PS was fully encased in yellow stones, forming an LSSC. FREDDY laser lithotripsy (U-100 Plus; World of Medicine, Berlin, Germany) was applied at the stent-stone interface under direct visualization to fragment the stones and gradually release the stent. The stent was successfully removed, and residual stones were cleared ([Fig. 3], [Video 1]). The patient recovered well and was discharged three days later.

Fig. 1 Initial ERCP findings (3 y prior). a Cholangiography showed a smooth, symmetrical stricture in the pancreatic segment of the common bile duct with upstream dilation. b Pancreatography revealed a slender, smooth stricture in the pancreatic head region of the main pancreatic duct, with mild dilation in the body and tail. c Plastic stents were placed in both the bile and pancreatic ducts.

Fig. 2 Emergency ERCP findings (1 mo prior). a Biliary and pancreatic plastic stents were seen in situ, with cast-like pancreatic duct stones along the pancreatic stent. b Cholangiography revealed a round filling defect encasing the stent, forming a lollipop-shaped stent-stone complex. c A second biliary stent was placed alongside the original.

Fig. 3 POCS-guided laser lithotripsy for LSSC removal. a POCS visualized a blue plastic stent encased in yellow stones, forming an LSSC. b, c A laser fiber was applied to the stent-stone interface and large stone. d Lithotripsy successfully fragmented the stone. e Cholangiography confirmed LSSC resolution and stone fragmentation. f Both stent and stone fragments were removed; balloon-occluded cholangiography showed no residual filling defects.

LSSC formation is associated with long-term stent retention (≥301 days) and CBD dilation [2]. The potential for LSSC formation should be considered in patients with long-term PS indwelling and dilated CBD. Endoscopic LSSC removal is technically challenging: standard endoscopic tools may fail, and forcible extraction risks ductal injury and perforation. Extracorporeal shock wave lithotripsy is technically complex [3], while surgical intervention is traumatic. FREDDY laser lithotripsy is safer than Ho:YAG laser and electrohydraulic lithotripsy [4] [5]. POCS-guided FREDDY laser lithotripsy offers a safe, minimally invasive, and effective approach for LSSC management.

Removal of lollipop-shaped stent-stone complex using direct-vision laser lithotripsy.Video 1

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Conflict of Interest

The authors declare that they have no conflict of interest.

• References

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Publication History

Article published online:
29 July 2025