title: Improvement in proximal aortic endograft fixation: an experimental study using different stent-grafts in human cadaveric aortas.
abstract: OBJECTIVE
  To compare the proximal fixation characteristics of different types of stent-grafts (SG) and the adjunctive effect of a proximally placed Palmaz stent.
  
  
  METHODS
  Human cadaveric aortas were obtained at autopsy and cut into 30 aortic segments. Appropriately oversized (10% to 20%) commercial stent-grafts (Zenith, Ancure, Excluder, Talent) and 4 configurations of homemade Palmaz-based stent-grafts (polytetrafluoroethylene or polyester coverings each with no uncovered proximal edge or a 20-mm bare section of stent) were implanted 20 mm into an aortic segment and balloon dilated. Each segment was placed in an experimental apparatus to measure the dislodgment force. Bare Palmaz stents were used to reinforce the proximal fixation of the commercial stent-grafts, and the measurements were repeated. Manual anastomoses were made and their dislodgment force tested for comparison.
  
  
  RESULTS
  The median dislodgment force ranged from 6.5 N for the Excluder to 26.5 N for the Zenith (8.0 N for the Talent, 11.8 N for the Ancure, and 8.1 to 10.7 N for the various Palmaz stent-graft designs). There was no significant difference between the Zenith and the Ancure groups or between the Excluder and the Talent groups. However, the Zenith and Ancure devices required significantly higher (p=0.0004) force (approximately 25%) to displace them than the other stent-grafts tested. With the Palmaz stent added to the proximal attachment site, the median dislodgment force for the different commercial endografts was significantly improved for all devices (p<0.03): 34% for the Zenith device, 69% for the Ancure, 73% for the Talent, and 80% for the Excluder endoprosthesis.
  
  
  CONCLUSIONS
  The Zenith stent-graft had the best resistance to dislodgment. An additional Palmaz stent placed at the proximal attachment site greatly improves endograft fixation regardless of the type of stent-graft. For complex aneurysm necks or for intraoperative type I endoleak management, an adjunctive Palmaz stent could be used.
authors.affiliation: Department of Vascular Surgery, Hôpital Arnaud de Villeneuve, CHU Montpellier, France. reuben.veerapen@laposte.net
authors.forename: Reuben
authors.initials: R
authors.lastname: Veerapen
authors.forename: Anne
authors.initials: A
authors.lastname: Dorandeu
authors.forename: Isabelle
authors.initials: I
authors.lastname: Serre
authors.forename: Jean-Phillipe
authors.initials: JP
authors.lastname: Berthet
authors.forename: Charles Henri
authors.initials: CH
authors.lastname: Marty-Ane
authors.forename: Henri
authors.initials: H
authors.lastname: Mary
authors.forename: Pierre
authors.initials: P
authors.lastname: Alric
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal; D001013:Aorta, Thoracic; D001014:Aortic Aneurysm / Q000628:therapy*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods*; D002102:Cadaver; D006801:Humans; D008875:Middle Aged; D011336:Probability; D011474:Prosthesis Design; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D015607:Stents