title: Coronary stent durability and fracture: an independent bench comparison of six contemporary designs using a repetitive bend test.
abstract: OBJECTIVE
  Stent fracture is important because it may cause adverse events. The interventional cardiologist needs independent data to aid stent selection. Stent designers need data to improve stent design. We used a repetitive bend test to compare durability and fracture for different stent designs.
  
  
  RESULTS
  Tested were 15 examples of six designs (BioMatrix Flex, Vision, MULTI-LINK 8, Element, Promus PREMIER and Integrity). One end of a nominally deployed stent was mounted on a fixed mandrel. The other end was translated a distance of ±3.5 mm at a rate of 6 Hz until fracture or 10 million cycles completed. The numbers of cycles to fracture for the Vision design (288,411±193,391) and the MULTI-LINK 8 (314,475±239,869) were significantly greater than for the BioMatrix Flex design (38,904±13,160), p<0.001. The difference between Vision and MULTI-LINK 8 was not significant (p=0.79). The Element, PREMIER, and Integrity designs did not fracture. Most fractures were in the curved portions of connectors between hoops.
  
  
  CONCLUSIONS
  The stent design which fractured most readily was the BioMatrix Flex. The most flexible designs did not fracture and, in general, stents with three connectors were more likely to fracture than those with two connectors between loops.
authors.affiliation: Mercy Angiography, Auckland, New Zealand.
authors.forename: John A
authors.initials: JA
authors.lastname: Ormiston
authors.forename: Bruce
authors.initials: B
authors.lastname: Webber
authors.forename: Ben
authors.initials: B
authors.lastname: Ubod
authors.forename: Jonathon
authors.initials: J
authors.lastname: White
authors.forename: Mark W I
authors.initials: MW
authors.lastname: Webster
mesh_terms: D054855:Drug-Eluting Stents; D006801:Humans; D008422:Materials Testing; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013314:Stress, Mechanical; D055114:X-Ray Microtomography