title: Fractures of self-expanding metallic stents in periampullary malignant biliary obstruction.
abstract: BACKGROUND
  Self-expanding metallic stents are widely used for relieving biliary duct obstruction in patients with unresectable periampullary malignancies. However, only a few studies have assessed the occurrence of fractures in these stents.
  
  
  OBJECTIVE
  To determine the prevalence and significance of stent fracture after placement of self-expanding metallic stents for periampullary malignant biliary obstruction.
  
  
  METHODS
  Over a 5-year period, 48 patients underwent placement of self-expanding metallic stents for periampullary malignant biliary obstructions. Stents were introduced 2-6 weeks after a percutaneous transhepatic biliary decompression. The medical records and relevant images were reviewed for stent patency, stent fracture, type of stent, and stent-related complications.
  
  
  RESULTS
  Stent fracture was detected in four of the 48 patients (8%): in one patient at 1 month and in three patients between 10 and 21 months after stenting. All four fractures involved one type of nitinol stent used in 38 patients. In one of the patients, fracture was complicated by life-threatening gastrointestinal bleeding. The mean survival time for all patients was 251 days (standard deviation [SD]+/-275 days) and the mean overall patency time for all stents was 187 days (SD+/-205 days).
  
  
  CONCLUSIONS
  Stent fracture occurs after placement of self-expanding nitinol stents for periampullary malignant biliary obstruction. The low reported incidence of this complication may be due to a lack of awareness of and difficulty in detecting stent fracture. Fracture should be considered as a possible contributing factor in recurrent biliary obstruction after self-expanding metallic stent insertion.
authors: Department of Surgery, University Hospital, Uppsala, Sweden. ib.rasmussen@surgsci.uu.se
authors: I C
authors: IC
authors: Rasmussen
authors: U
authors: U
authors: Dahlstrand
authors: G
authors: G
authors: Sandblom
authors: L G
authors: LG
authors: Eriksson
authors: R
authors: R
authors: Nyman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000497:Alloys; D001650:Bile Duct Neoplasms / Q000150:complications* / Q000556:secondary*; D002758:Cholangiography; D002779:Cholestasis / Q000209:etiology / Q000473:pathology / Q000628:therapy*; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000473:pathology*; D011475:Prosthesis Failure; D015607:Stents / Q000009:adverse effects*
chemical_list: D000497:Alloys; C013616:nitinol