title: In vivo evaluation of a biolimus eluting nickel titanium self expanding stent with overlapping balloon expandable drug eluting and bare metal stents in a porcine coronary model.
abstract: OBJECTIVE
  Long lesions and complex vessel anatomy frequently require the use of overlapping stents to treat a lesion. The purpose of this study was to evaluate the long-term effects of overlapping the Axxess Biolimus A9 eluting stent (BES) with two of the most commonly used, commercially available drug eluting stents. These stents were compared to BxVelocity bare metal (BMS) stents in a porcine coronary stent-injury model.
  
  
  RESULTS
  Nineteen juvenile farm swine, 25-35 kg in weight, 3-6 months in age were utilised. Each animal received an Axxess stent to their coronary artery as permitted by the individual animal's anatomy. A second stent, either a Cypher, sirolimus eluting stent (SES) or, a Taxus, paclitaxel eluting stent (PES), or a BxVelocity bare metal stent (BMS) were implanted in an overlapped fashion. The animals were then followed for either 28 or 180 days as specified by a randomisation scheme. At the end of each follow-up period, they were euthenised, and the vessels containing the overlapping stents were harvested, processed into histological sections, and analysed. Compared to bare metal stents, overlapped segments using DES exhibited delayed vascular healing compared to both the proximal and distal non-overlap sites at each of the follow-up time point. Overall, in the non-overlap stent segments, SES induced significantly more inflammation and neointimal hyperplasia compared to PES and BMS.
  
  
  CONCLUSIONS
  In this study of BMS and two different types of DES overlapped with the Axxess Biolimus A9 eluting stent, we found that while there was a delay in the degree of vascular healing with DES compared to BMS, the specific type of DES that was overlapped with BES did not affect the behaviour of the overlap zone in terms of most of the histomorphometric measures at 28 or 180 days. This was true whether the stent was drug eluting or bare metal. More inflammation with delayed healing was seen in the SES compared to PES and BMS.
authors.affiliation: Division of Cardiology, Department of Medicine, Janey Briscoe Center for Cardiovascular Research, University of Texas Health Science Center in San Antonio, TX 78229-3900, USA.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Cilingiroglu
authors.forename: James
authors.initials: J
authors.lastname: Elliott
authors.forename: Pramod
authors.initials: P
authors.lastname: Sangi
authors.forename: Holly
authors.initials: H
authors.lastname: Matthews
authors.forename: Fermin
authors.initials: F
authors.lastname: Tio
authors.forename: Brett
authors.initials: B
authors.lastname: Trauthen
authors.forename: John
authors.initials: J
authors.lastname: Elicker
authors.forename: Steven R
authors.initials: SR
authors.lastname: Bailey
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation*; D000818:Animals; D002317:Cardiovascular Agents / Q000008:administration & dosage*; D049109:Cell Proliferation; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000187:drug effects / Q000473:pathology*; D054855:Drug-Eluting Stents; D006965:Hyperplasia; D007249:Inflammation / Q000209:etiology / Q000473:pathology; D023421:Models, Animal; D009532:Nickel; D017239:Paclitaxel / Q000008:administration & dosage; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011474:Prosthesis Design; D020123:Sirolimus / Q000008:administration & dosage / Q000031:analogs & derivatives*; D015607:Stents; D013552:Swine; D013997:Time Factors; D014025:Titanium; D014945:Wound Healing
chemical_list: D002317:Cardiovascular Agents; D010975:Platelet Aggregation Inhibitors; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium; D017239:Paclitaxel; C518022:umirolimus; D020123:Sirolimus