title: Endoscopic management of malignant biliary obstruction by means of covered metallic stents: primary stent placement vs. re-intervention.
abstract: OBJECTIVE
  Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to increased rates of stent occlusion. Occlusion of covered metallic stents now occurs in about half of all patients with malignant biliary strictures. The removal of metallic stents followed by placement of a second stent has been attempted, but outcomes remain controversial. The aim of the current study was to evaluate the effectiveness and safety of the primary placement and secondary placement (re-intervention) of covered metallic stents and to assess the feasibility and safety of stent removal.
  
  
  METHODS
  The study included 186 patients with unresectable malignant biliary strictures who underwent primary stent placement between October 2001 and March 2010.  Covered biliary self-expandable metal stents (SEMSs) were removed in 39 of these patients, and 36 underwent re-intervention. The patency times, occlusion rates of the first stent and re-intervention, success rates of stent removal, and complications were investigated.
  
  
  RESULTS
  Covered SEMSs were placed in 186 patients. The median patency time of the first stent was 352 days. Stent occlusion occurred in 48.9 % of the patients and was mainly caused by debris or food residue (37 %), dislocation (19 %), and migration with hyperplasia (19 %). Stent removal was attempted in 50 patients and was successful without complication in 39 (78 %). Most of the patients in whom stent removal was unsuccessful had migration with hyperplasia. The median patency time of the second stent was 263 days. The stent patency time did not significantly differ between the first and the second stent.
  
  
  CONCLUSIONS
  Covered SEMSs could be safely removed at the time of stent occlusion. Patency rates were similar for initial stent placement and re-intervention.
authors.affiliation: Department of Gastroenterology, Kitasato University East Hospital, Sagamihara, Japan. m-kida@kitasato-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Kida
authors.forename: S
authors.initials: S
authors.lastname: Miyazawa
authors.forename: T
authors.initials: T
authors.lastname: Iwai
authors.forename: H
authors.initials: H
authors.lastname: Ikeda
authors.forename: M
authors.initials: M
authors.lastname: Takezawa
authors.forename: H
authors.initials: H
authors.lastname: Kikuchi
authors.forename: M
authors.initials: M
authors.lastname: Watanabe
authors.forename: H
authors.initials: H
authors.lastname: Imaizumi
authors.forename: W
authors.initials: W
authors.lastname: Koizumi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001661:Biliary Tract Neoplasms / Q000150:complications*; D002779:Cholestasis / Q000209:etiology / Q000628:therapy*; D020099:Coated Materials, Biocompatible; D020878:Device Removal; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008670:Metals; D008875:Middle Aged; D019233:Retreatment; D015607:Stents / Q000009:adverse effects
chemical_list: D020099:Coated Materials, Biocompatible; D008670:Metals