title: Carotid artery stent fracture identification and clinical relevance.
abstract: BACKGROUND
  This study was conducted to identify the prevalence, risk factors, and clinical relevance of carotid artery stent fracture.
  
  
  METHODS
  Commercially available carotid stents were implanted in this prospective, observational study that began in January 2004. Indications included asymptomatic patients (stenosis >80%), symptomatic patients (stenosis >60%), and ulcerated lesions (>50%). Stent integrity was assessed with plain radiography at 12 months. Data were analyzed in April 2009 on a series of 341 consecutive patients treated with carotid artery stenting with at least 12 months follow-up.
  
  
  RESULTS
  Stent fracture prevalence was 3.4% at 12 months (95% confidence interval, 1.7%-6.1%). The median clinical follow-up was 30 months (range, 12-64 months) for 323 eligible patients. Treatment included 23.6% of symptomatic patients. According to univariate analysis, calcification type III increased the odds of stent fracture by more than 4.5 times (odds ratio [OR], 4.74; P = .006) and angulation >45 degrees increased the odds of stent fracture by 6.5 times (OR, 6.51; P = .008). Carotid stent cell type, stent length, and stent over-sizing were not correlated with stent fracture incidence. Stent fracture was not associated with stroke (0%), transient ischemic attack (0%), or death (0%). Restenosis was significantly associated with stent fracture (P < .001). Multivariate analysis evidenced that type III calcification (OR, 3.90; P = .029) and angulation >45 degrees (OR, 4.69; P = .026) were important risk factors for carotid stent fracture.
  
  
  CONCLUSIONS
  Carotid stent fracture is a rare complication after CAS and is associated with vessel angulation, calcification, and restenosis. In this series, fracture identification was independent of stroke, transient ischemic attack, and mortality.
authors.affiliation: Department of Vascular Surgery, University of Modena and Reggio Emilia, Nuovo Ospedale S. Agostino Estense, Modena, Italy. chirvascmo@gmail.com
authors.forename: Gioacchino
authors.initials: G
authors.lastname: Coppi
authors.forename: Roberto
authors.initials: R
authors.lastname: Moratto
authors.forename: Jessica
authors.initials: J
authors.lastname: Veronesi
authors.forename: Emanuele
authors.initials: E
authors.lastname: Nicolosi
authors.forename: Roberto
authors.initials: R
authors.lastname: Silingardi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000800:Angioplasty, Balloon / Q000009:adverse effects / Q000295:instrumentation*; D002114:Calcinosis / Q000150:complications; D016893:Carotid Stenosis / Q000150:complications / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000209:etiology; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D011446:Prospective Studies; D011475:Prosthesis Failure; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D015607:Stents; D020521:Stroke / Q000209:etiology; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018615:Ultrasonography, Doppler, Color