title: Bilateral biliary drainage for malignant hilar obstruction using the 'stent-in-stent' method with a Y-stent:  efficacy and complications.
abstract: BACKGROUND
  The usefulness of bilateral stent placement for malignant hilar obstruction is still under debate. Nevertheless, many endoscopists advocate the placement of an endoscopic bilateral metal stent using various new devices and techniques.
  
  
  OBJECTIVE
  We compared the technical and clinical efficacy, and the short-term and long-term complications of the 'stent-in-stent' method using a Y-stent for malignant hilar obstruction between the early and the late period of this study.
  
  
  METHODS
  Ninety-seven patients treated with Y-stent implantation for malignant hilar obstruction were enrolled retrospectively. In 31 patients treated during the early period, bilateral Y-configured metal stents were placed for malignant hilar obstruction using the older designed Y-stent and a closed-cell second stent. The newly designed Y-stent and a slimmer open-cell second stent were introduced in 66 patients treated during the late period. New techniques learned through experience were gradually applied throughout the entire study period.
  
  
  RESULTS
  The rate of successful placement of bilateral stents was significantly higher in patients treated during the late period than those treated during the early period (58.1 vs. 87%; P=0.001). The functional success rate was 97.3%, with no difference between the early and the late periods. Cholangitis occurred as an early complication more frequently during the early period than during the late period (16.1 vs. 1.5%; P=0.012). Cholecystitis as a late complication occurred in 21 of 76 patients (27.6%). The incidence of late complications was similar between the early and the late periods.
  
  
  CONCLUSIONS
  With the development of new devices and increased technical experience, there were better outcomes during the late period compared with the early period. Endoscopic bilateral metal stenting using a Y-stent is an attractive option for the palliative treatment of malignant hilar obstruction.
authors.affiliation: Departments of Internal Medicine, Pusan National University Hospital, Busan, South Korea. amlm3@hanmail.net
authors.forename: Dong Uk
authors.initials: DU
authors.lastname: Kim
authors.forename: Dae Hwan
authors.initials: DH
authors.lastname: Kang
authors.forename: Gwang Ha
authors.initials: GH
authors.lastname: Kim
authors.forename: Geun Am
authors.initials: GA
authors.lastname: Song
authors.forename: Chang Won
authors.initials: CW
authors.lastname: Kim
authors.forename: Suk
authors.initials: S
authors.lastname: Kim
authors.forename: Ae Lee
authors.initials: AL
authors.lastname: Jang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000497:Alloys; D016009:Chi-Square Distribution; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000009:adverse effects / Q000295:instrumentation*; D002761:Cholangitis / Q000453:epidemiology; D002764:Cholecystitis / Q000453:epidemiology; D002779:Cholestasis / Q000000981:diagnostic imaging / Q000209:etiology / Q000628:therapy*; D004067:Digestive System Neoplasms / Q000150:complications*; D004322:Drainage / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D005260:Female; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010166:Palliative Care; D011474:Prosthesis Design; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D016717:Sphincterotomy, Endoscopic; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000497:Alloys; C013616:nitinol