title: Stent fractures after superficial femoral artery stenting: risk factors and impact on patency.
abstract: OBJECTIVE
  To determine the risk factors and clinical impact of stent fractures after superficial femoral artery (SFA) stenting.
  
  
  METHODS
  From May 2009 to June 2012, 171 consecutive patients (mean age 74.5±7.8, years; 106 men) who presented with SFA stenosis or occlusion in 205 limbs underwent stent implantation in the SFA at a single center. Stent fractures were determined by radiography and classified into types I through V. Loss of patency was assessed by duplex ultrasonography (>2.4 peak systolic velocity ratio) or angiography (percent diameter stenosis >50%).
  
  
  RESULTS
  The 12- and 24-month primary patency rates were 49.8% and 43.4%, respectively. Stent fractures occurred in 12.5% and 26.8% per limb (6.6% and 19.4% per stent) at 12 and 24 months, respectively. Primary patency was numerically worse in the stent fracture group but not statistically different from the group without fractures at 2 years. Primary patency for different classes of stent fracture were 30.8% (type I), 50.0% (type II), and 31.3% (type III-V). Hyperlipidemia (p=0.001), TransAtlantic Inter-Society Consensus II classification (p=0.007), chronic total occlusion (CTO; p<0.001), proximal lesion location (p=0.008), lesion calcification (p=0.025), total stent length (p=0.005), stent diameter (p=0.001), and number of stents (p=0.001) were statistically significant predictors of stent fracture. Multivariate analysis showed that CTO (hazard ratio 0.173, 95% confidence interval 0.042 to 0.716, p=0.015) was an independent predictor of stent fracture.
  
  
  CONCLUSIONS
  Stent fractures occur more frequently in patients with CTOs after treatment of longer stented lesions. Although multivariate analysis showed that CTO was the only independent predictor regardless of stent length or number, the stent fracture rate was numerically higher in the severe calcification and proximal SFA lesion subgroups. Stent fracture did not appear to affect long-term patency rates, but this is yet to be confirmed with further follow-up.
authors: Institute of Vascular Surgery, Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China.
authors: Yuting
authors: Y
authors: Lin
authors: Institute of Vascular Surgery, Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China.
authors: Xiao
authors: X
authors: Tang
authors: Institute of Vascular Surgery, Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China.
authors: Weiguo
authors: W
authors: Fu
authors: Division of Interventional Cardiology and Endovascular Medicine, Deborah Heart and Lung Center, Browns Mills, NJ, USA.
authors: Richard
authors: R
authors: Kovach
authors: Division of Interventional Cardiology and Endovascular Medicine, Deborah Heart and Lung Center, Browns Mills, NJ, USA.
authors: Jon C
authors: JC
authors: George
authors: Institute of Vascular Surgery, Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China guo.daqiao@zs-hospital.sh.cn.
authors: Daqiao
authors: D
authors: Guo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D016208:Databases, Factual; D057510:Endovascular Procedures / Q000009:adverse effects / Q000295:instrumentation*; D005260:Female; D005263:Femoral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D058729:Peripheral Arterial Disease / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex; D061205:Vascular Calcification / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D014654:Vascular Patency
keywords: chronic total occlusion; complication; fracture; overlapping stents; patency; stenosis; stent; superficial femoral artery