title: De novo stent-stone complex after long-term biliary stent placement: pathogenesis, diagnosis, and endotherapy.
abstract: BACKGROUND
  Long-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.
  
  
  METHODS
  Here we report 3 new cases and review 7 other cases of de novo stent-stone complex formation after long-term biliary stent placement.
  
  
  METHODS
  De 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).
  
  
  RESULTS
  The 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).
  
  
  CONCLUSIONS
  It 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.
authors.affiliation: Division of Digestive Diseases, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390-8887, USA, and Center for Therapeutic Endoscopy and Endoscopic Oncology, St Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Shou-jiang
authors.initials: SJ
authors.lastname: Tang
authors.forename: Luis
authors.initials: L
authors.lastname: Armstrong
authors.forename: Luis F
authors.initials: LF
authors.lastname: Lara
authors.forename: Paul
authors.initials: P
authors.lastname: Kortan
mesh_terms: D000328:Adult; D002760:Cholangiopancreatography, Endoscopic Retrograde; D002779:Cholestasis / Q000628:therapy; D005260:Female; D042882:Gallstones / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy*; D006801:Humans; D008096:Lithotripsy / Q000379:methods*; D008297:Male; D015607:Stents / Q000009:adverse effects*; D013997:Time Factors