title: Evaluation of a bifurcation drug-eluting stent system versus provisional T-stenting in a perfused synthetic coronary artery model.
abstract: BACKGROUND
  Provisional T-stenting is a widely used strategy for the treatment of coronary artery bifurcation lesions. However, the use of conventional stents in this setting is limited by multiple factors; this includes technical considerations such as wire wrap when accessing the involved vessel, and stent overlap at or near the carina of the lesion. In addition, current slotted tube stent technology tends to be associated with gaps in the coverage of the side branch ostium, which may result in restenosis in that segment of the lesion. The Pathfinder device, now more commonly referred to as the Xience Side Branch Access System (Xience SBA) is a drug-eluting stent (DES) designed specifically to assist in the treatment of bifurcation lesions by allowing wire access into the side branch, irrespective of the treatment strategy to be employed.
  
  
  METHODS
  The Xience SBA drug-eluting stent was compared with the standard Vision coronary stent system using a provisional T-stenting strategy in a perfused synthetic model of the coronary vasculature with side branch angulations of 30 degrees , 50 degrees , 70 degrees , and 90 degrees . Stent delivery was performed under fluoroscopic guidance. Following the procedure, high-resolution 2D Faxitron imaging was used to evaluate deployment accuracy of the side branch stent relative to the main branch stent.
  
  
  RESULTS
  Deployment of the Xience SBA was accomplished in the same total time as the standard stents in a provisional T-stenting approach (14.9 vs. 14.6 minutes). However, the time required to achieve stent deployment in the main branch was less with the Xience SBA (4.0 vs. 6.6 minutes), and as a result, total contrast usage (49.4 vs. 69.4 cm(3)) and fluoroscopy time (5.1 vs. 6.2 minutes) was lower. Additionally, the Xience SBA had a lower incidence of wire wrap (22% vs. 89%) and less distal protrusion of the side branch stent into the main branch (0.54 vs. 1.21 mm). Significant gaps in ostial side branch coverage were not seen in either group.
  
  
  CONCLUSIONS
  The Xience Side Branch Access DES is a viable device for consistently accessing coronary bifurcation lesions; it allows for easy wire access into the side branch. This may assist the operator in overcoming those well-recognized limitations associated with use of standard one- or two-stent strategies. In this perfused synthetic coronary model, Xience SBA deployment required less contrast usage and shorter fluoroscopy times. Further testing of this device is warranted.
authors.affiliation: Scottsdale Heart Group, Scottsdale Healthcare Hospitals, Scottsdale, Arizona 85258, USA. davidrizik@aol.com
authors.forename: David G
authors.initials: DG
authors.lastname: Rizik
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Klag
authors.forename: Alan
authors.initials: A
authors.lastname: Tenaglia
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Hatten
authors.forename: Marianne
authors.initials: M
authors.lastname: Barnhart
authors.forename: Boris
authors.initials: B
authors.lastname: Warnack
mesh_terms: D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000628:therapy*; D003328:Coronary Thrombosis / Q000517:prevention & control; D003331:Coronary Vessels / Q000473:pathology*; D054855:Drug-Eluting Stents; D005471:Fluoroscopy; D006439:Hemodynamics; D006801:Humans; D008953:Models, Anatomic; D010865:Pilot Projects; D013997:Time Factors