title: How to predict the outcome of endoscopic mechanical lithotripsy in patients with difficult bile duct stones?
abstract: OBJECTIVE
  Endoscopic mechanical lithotripsy is frequently used to overcome the difficulties of removing large bile duct stones endoscopically. The aim of this study was to identify predictors of endoscopic mechanical lithotripsy failure.
  
  
  METHODS
  One hundred and thirty-four patients who underwent mechanical lithotripsy for difficult choledocholithiasis were evaluated retrospectively. Predictive factors of outcome and procedure-related complications were analyzed. The clinical outcomes of subsequent management were also evaluated in cases of unsuccessful endoscopic mechanical lithotripsy.
  
  
  RESULTS
  Endoscopic mechanical lithotripsy was successful in 102 patients (76.1%). Stone impaction, size (>or=30 mm), and the stone size to bile duct diameter ratio (>1.0) were significant predictors of endoscopic mechanical lithotripsy failure, with estimated odds ratios of 17.83, 4.32 and 5.47, respectively. There was no difference in complication rates between the successful and failed mechanical lithotripsy groups. When mechanical lithotripsy failed, all patients were successfully treated using various modalities, including surgery, without mortality.
  
  
  CONCLUSIONS
  An impacted stone, stone size (>or=30 mm) and stone size to bile duct diameter ratio (>1.0) were predictors of failure of endoscopic mechanical lithotripsy for a difficult bile duct stone. Alternative approaches should be considered in patients with predictors of unsuccessful endoscopic mechanical lithotripsy in order to avoid wasting time and resources.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sang Hyub
authors.initials: SH
authors.lastname: Lee
authors.forename: Joo Kyung
authors.initials: JK
authors.lastname: Park
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Yoon
authors.forename: Jun Kyu
authors.initials: JK
authors.lastname: Lee
authors.forename: Ji Kon
authors.initials: JK
authors.lastname: Ryu
authors.forename: Yong-Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Yong Bum Bum
authors.initials: YB
authors.lastname: Yoon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016145:Endoscopy, Digestive System; D005260:Female; D042882:Gallstones / Q000628:therapy*; D006801:Humans; D008096:Lithotripsy / Q000379:methods; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D017211:Treatment Failure