title: Partially covered self-expanding metal stent for unresectable malignant extrahepatic biliary obstruction: results of a large prospective series.
abstract: BACKGROUND
  Endoscopic biliary stenting is a well-established palliative treatment in patients with unresectable malignant biliary strictures. Obstruction of uncovered self-expanding metal stent (SEMS) due to tumor ingrowth is the most frequent complication. Partially covered SEMS might increase stent patency but could favor complications related to stent covering, such as pancreatitis, cholecystitis, and migration. The aim of this study was to evaluate the efficacy and safety of partially covered SEMS in patients with an unresectable malignant biliary stricture.
  
  
  METHODS
  Patients with malignant extrahepatic biliary obstruction treated endoscopically with partially covered SEMS were included in this multicenter, prospective, nonrandomized study.
  
  
  RESULTS
  One hundred ninety-nine patients were endoscopically treated with partially covered SEMS in 32 Spanish hospitals. Clinical success after deep cannulation was 96%. Early complications occurred in 4% (3 pancreatitis, 2 cholangitis, 1 hemorrhage, 1 perforation, and 1 cholecystitis). Late complications occurred in 19.5% (18 obstructions, 10 migrations, 6 cholangitis without obstruction, 3 acute cholecystitis, and 2 pancreatitis), with no tumor ingrowth in any case. Median stent patency was 138.9 ± 112.6 days. One-year actuarial probability of stent patency was 70% and that of nonmigration was 86%. Multivariate analysis showed adjuvant radio- or chemotherapy as the only independent predictive factor of stent patency and previous insertion of a biliary stent was the only predictive factor of migration.
  
  
  CONCLUSIONS
  The partially covered SEMS was easily inserted, had a high clinical success rate, and prevented tumor ingrowth. The incidence of possible complications related to stent coverage, namely, migration, pancreatitis, and cholecystitis, was lower than in previously published series.
authors.affiliation: Endoscopy Unit, Service of Gastroenterology, Hospital de la Santa Creu i Sant Pau, Sant Quintí 89, 08041, Barcelona, Spain. cgomezo@santpau.cat
authors.forename: Cristina
authors.initials: C
authors.lastname: Gómez-Oliva
authors.forename: Carlos
authors.initials: C
authors.lastname: Guarner-Argente
authors.forename: Mar
authors.initials: M
authors.lastname: Concepción
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Jiménez
authors.forename: Sarbelio
authors.initials: S
authors.lastname: Rodríguez
authors.forename: Ferran
authors.initials: F
authors.lastname: Gonzalez-Huix
authors.forename: Fernando
authors.initials: F
authors.lastname: Mugica
authors.forename: José Luis
authors.initials: JL
authors.lastname: Cabriada
authors.forename: Claudio
authors.initials: C
authors.lastname: Rodríguez
authors.forename: Carlos Guarner
authors.initials: CG
authors.lastname: Aguilar
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001661:Biliary Tract Neoplasms / Q000150:complications / Q000401:mortality / Q000601:surgery*; D002760:Cholangiopancreatography, Endoscopic Retrograde; D001651:Cholestasis, Extrahepatic / Q000209:etiology / Q000401:mortality / Q000601:surgery*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010166:Palliative Care / Q000379:methods; D011183:Postoperative Complications / Q000209:etiology / Q000401:mortality; D011446:Prospective Studies; D011475:Prosthesis Failure / Q000009:adverse effects; D015607:Stents