De novo stent-stone complex after long-term biliary stent placement: pathogenesis, diagnosis, and endotherapy

BackgroundLong-term and permanent biliary stenting have been reported in many studies and are infrequently practiced in selected patients with irretrievable common bile duct stones and biliary strictures.PatientsHere we report 3 new cases and review 7 other cases of de novo stent-stone complex formation after long-term biliary stent placement.InterventionsDe novo stent-stone complexes developed in 3 young patients after unintended long-term biliary stent placement of 4.5 to 11 years' duration. The stent-stone complexes were successfully removed during ERCP with electrohydrolic lithotripsy (EHL) in combination with choledochoscopy or extracorporeal shock wave lithotripsy (ESWL) with mechanical lithotripsy (ML).ResultsThe de novo radiolucent stones formed around and above the stent in the proximal and end part of the stent. The stones were generally large with a diameter >2 to 3 cm. The stent-stone complex usually assumed a 1-sided dumbbell configuration inside the bile duct. The mean duration to clinical presentation after initial biliary stenting is 5.64 years (range 2-11 years).ConclusionsIt is important to keep in mind that a biliary stent can act as a nidus for new biliary stone formation around the stent after long-term placement. We recommend that the optimal endotherapy in this situation is ML for the free-floating complexes with short stents, and choledochoscopy with EHL or laser lithotripsy and ESWL for impacted complexes with longer stents.