title: The "crush" technique for coronary artery bifurcation stenting: insights from micro-computed tomographic imaging of bench deployments.
abstract: OBJECTIVE
  This study provides insights into "crush" coronary bifurcation stenting through imaging of bench deployments.
  
  
  BACKGROUND
  Although the strategy of provisional side-branch stenting is widely accepted for suitable bifurcation lesions, there is no consensus on the best option for elective stenting with 2 stents. The crush technique has the potential to scaffold and apply the drug to the side-branch ostium where restenosis is most common.
  
  
  METHODS
  Sequential steps of crush stent deployment and post-dilation were undertaken in silicone phantoms and recorded on cine angiography and microcomputed tomography. We assessed the effect of deployment strategies, post-dilation strategies, and cell size on side-branch ostial area.
  
  
  RESULTS
  Side-branch ostial coverage by metal struts was 53% (95% confidence interval [CI]: 46 to 59) after 1-step kissing post-dilation and was reduced by 2-step kissing post-dilation to 33% (95% CI: 28 to 37; p < 0.0001). Although the residual stenosis after the classical crush strategy was 47% (95% CI: 39 to 53), it was 36% (95% CI: 31 to 40; p = 0.002) after mini-crush deployment. Stents with larger cell size (>3.5 mm diameter) had a residual stenosis of 37% (95% CI: 32 to 42) after crush deployment that was less than the residual stenosis for stents with smaller cell size (52%; 95% CI: 44 to 60; p < 0.0001).
  
  
  CONCLUSIONS
  Side-branch ostial stenosis after crush stenting was minimized by mini-crush deployment, 2-step kissing post-dilation, and the use of stents with larger cell size. It is unknown if optimizing stent deployment at bifurcation lesions will reduce clinical stent thrombosis and restenosis.
authors.affiliation: Mercy Angiography, Mercy Hospital, Auckland, New Zealand. johno@mercyangiography.co.nz
authors.forename: John A
authors.initials: JA
authors.lastname: Ormiston
authors.forename: Mark W I
authors.initials: MW
authors.lastname: Webster
authors.forename: Bruce
authors.initials: B
authors.lastname: Webber
authors.forename: James T
authors.initials: JT
authors.lastname: Stewart
authors.forename: Peter N
authors.initials: PN
authors.lastname: Ruygrok
authors.forename: Robert I
authors.initials: RI
authors.lastname: Hatrick
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000295:instrumentation* / Q000379:methods*; D002932:Cineangiography; D017023:Coronary Angiography / Q000295:instrumentation / Q000379:methods*; D003331:Coronary Vessels / Q000473:pathology*; D008422:Materials Testing; D019047:Phantoms, Imaging; D011474:Prosthesis Design; D015203:Reproducibility of Results; D012828:Silicones; D015607:Stents; D055114:X-Ray Microtomography / Q000295:instrumentation
chemical_list: D012828:Silicones