title: Influence of stent fracture on the long-term patency in the femoro-popliteal artery: experience of 4 years.
abstract: OBJECTIVE
  We investigated the time course of stent patency in the femoro-popliteal artery for as long as 4 years.
  
  
  BACKGROUND
  Stent fracture has been related to poor 2-year patency in the femoro-popliteal artery.
  
  
  METHODS
  We studied 239 consecutive patients who underwent provisional de novo stenting with nitinol stents for 333 limbs (Luminexx stent [C. R. Bard, Inc., Murray Hill, New Jersey] in 91 limbs; Smart stent [Cordis Corp., Miami Lakes, Florida] in 242 limbs) from April 2004 to December 2007. Stent fracture was determined by X-ray with multiple projections. Patency was assessed by duplex ultrasonography as peak systolic velocity ratio <2.4 or by angiography (% diameter stenosis <50%). Primary patency in those with and without stent fracture at follow-up was assessed along with factors influencing stent fracture.
  
  
  RESULTS
  Primary patency was 81%, 74%, 68%, and 65% at 1, 2, 3, and 4 years, respectively. Stent fracture occurred in 14% (78 of 544) per stent and 17% (55 of 333) per limbs. Stent fracture was significantly associated with multiple stent deployments (with fracture = 2.3 +/- 0.9 stents vs. without fracture = 1.5 +/- 0.7 stents, p < 0.001) and long lesions (with fracture = 208 +/- 84 mm vs. without fracture = 121 +/- 79 mm, p < 0.001). Primary patency was 68% with fracture versus 83% without fracture at 1 year, p = 0.03; 65% versus 75% at 2 years, p = 0.05; 61% versus 69% at 3 years, p = 0.06; and 61% versus 65% at 4 years, p = 0.07. Neither type 1 nor type 3 fracture affected patency, although type 2 showed the worst patency.
  
  
  CONCLUSIONS
  Stent fracture worsened the patency during the first 2 years, but it did not apparently affect patency beyond 2 years. In particular, complete stent separation did not affect patency.
authors.affiliation: Kansai Rosai Hospital, Hyogo, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Iida
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Nanto
authors.forename: Masaaki
authors.initials: M
authors.lastname: Uematsu
authors.forename: Kuniyasu
authors.initials: K
authors.lastname: Ikeoka
authors.forename: Shin
authors.initials: S
authors.lastname: Okamoto
authors.forename: Seiki
authors.initials: S
authors.lastname: Nagata
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000497:Alloys; D000800:Angioplasty, Balloon / Q000295:instrumentation*; D001157:Arterial Occlusive Diseases / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D003251:Constriction, Pathologic; D005260:Female; D005263:Femoral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D011150:Popliteal Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012189:Retrospective Studies; D012720:Severity of Illness Index; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex; D014654:Vascular Patency
chemical_list: D000497:Alloys; C013616:nitinol