title: Long-term follow-up after peroral cholangioscopy-directed lithotripsy in patients with difficult bile duct stones, including Mirizzi syndrome: an analysis of risk factors predicting stone recurrence.
abstract: BACKGROUND
  Peroral cholangioscopy-directed lithotripsy (PC-directed lithotripsy) has been successfully used for the treatment of difficult bile duct stones, including Mirizzi syndrome (MS). However, long-term outcome and risk factors for stone recurrence after PC-directed lithotripsy have not yet been elucidated. The aim of this study was to assess the outcomes of long-term follow-up after PC-directed lithotripsy and to clarify risk factors predicting stone recurrence.
  
  
  METHODS
  One hundred twenty-two consecutive patients with difficult bile duct stones, including MS type II (McSherry classification system), were included in the study.
  
  
  RESULTS
  Successful stone removal was achieved in 117 (95.9%) of the 122 patients treated with PC-directed lithotripsy. Of these 117 patients, reliable follow-up information for a median period of 5.5 years (range=0.19-16.6) was obtained for 111 patients (94.9%) in whom stone type was classified into one of the following three categories: (1) MS type II (47 patients); (2) impacted stones (45 patients); and (3) large stones (≥20 mm in short diameter, 19 patients). Bile duct stone recurrence was observed in 18 patients (16.1%), of whom 4 had MS type II, 9 had impacted stones, and 5 had large stones. Statistical analysis showed that dilated bile duct diameter greater than or equal to 20 mm was the only risk factor for stone recurrence.
  
  
  CONCLUSIONS
  PC-directed lithotripsy used for the treatment of difficult bile duct stones, including MS type II and impacted stones, and is found to be safe at long-term follow-up. Dilated bile duct diameter is the only risk factor for stone recurrence. Careful follow-up is indispensable, particularly for patients with dilated bile ducts.
authors.affiliation: Department of Gastroenterology and Clinical Oncology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. tsuyuguchi@faculty.chiba-u.jp
authors.forename: Toshio
authors.initials: T
authors.lastname: Tsuyuguchi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sakai
authors.forename: Harutoshi
authors.initials: H
authors.lastname: Sugiyama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ishihara
authors.forename: Osamu
authors.initials: O
authors.lastname: Yokosuka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D002760:Cholangiopancreatography, Endoscopic Retrograde; D016145:Endoscopy, Digestive System; D005260:Female; D005500:Follow-Up Studies; D042882:Gallstones / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D008096:Lithotripsy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D057792:Mirizzi Syndrome / Q000000981:diagnostic imaging / Q000628:therapy*; D016016:Proportional Hazards Models; D012008:Recurrence; D012307:Risk Factors; D016896:Treatment Outcome