title: Prevalence, factors, and clinical impact of self-expanding stent fractures following iliac artery stenting.
abstract: OBJECTIVE
  To evaluate the prevalence, factors, and clinical impact of self-expanding stent fracture following iliac artery stenting.
  
  
  METHODS
  A review of the endovascular registry database for our department showed 353 patients with occlusive diseases of the iliac artery who underwent stenting between 1997 and 2007. While clinical data and images were retrospectively reviewed for all patients, 165 patients who underwent self-expanding stenting and plain radiograph with >or=6-months follow-up were analyzed. Mean follow-up was 43 months for 305 stents (elgiloy, n = 83; nitinol, n = 222) implanted in 216 iliac arteries. The mean duration until the last imaging study was 38 months. Items concerning prevalence of stent fracture, factors associated with fracture, and outcomes for patients with stent fracture were analyzed.
  
  
  RESULTS
  Stent fracture was detected in 11 of 216 iliac arteries (5.1%). In stent-based analysis, 11 of 305 stents (3.6%) showed stent fracture, classified as type I in 2 stents, type II in 3 stents, type III in 4 stents, type IV in 1 stent, and type V in 1 stent. Stent fracture was detected in 11 of 222 nitinol stents (5.0%), but no Elgiloy stents. Cox proportional hazards regression model indicated stenting for chronic occlusion as a risk factor associated with nitinol stent fracture (hazard ratio [HR] = 6.09, P = 0.008, 95% confidence interval [CI] 1.59-23.3). Cumulative primary patency rates in iliac arteries with and without fractured stents were 90% and 91% at 8 years (P = .80), respectively.
  
  
  CONCLUSIONS
  Fracture of self-expanding stents is rare in iliac arteries, but stenting for chronic occlusion represents a risk factor for fracture. Fractures of stents placed in iliac arteries rarely affect patency.
authors.affiliation: Department of Radiology, Nara Medical University School of Medicine, Nara, Japan. wataruhigashiura@hotmail.com
authors.forename: Wataru
authors.initials: W
authors.lastname: Higashiura
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kubota
authors.forename: Shoji
authors.initials: S
authors.lastname: Sakaguchi
authors.forename: Norio
authors.initials: N
authors.lastname: Kurumatani
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Nakamae
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Nishimine
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Kichikawa
mesh_terms: D000368:Aged; D000497:Alloys; D000800:Angioplasty, Balloon / Q000009:adverse effects / Q000295:instrumentation*; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D002908:Chronic Disease; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015607:Stents; D013997:Time Factors; D017211:Treatment Failure; D014654:Vascular Patency
chemical_list: D000497:Alloys; C013616:nitinol