title: Stent-protected carotid angioplasty using a membrane stent: a comparative cadaver study.
abstract: OBJECTIVE
  To evaluate the performance of a prototype membrane stent, MembraX, in the prevention of acute and late embolization and to quantify particle embolization during carotid stent placement in human carotid explants in a proof of concept study.
  
  
  METHODS
  Thirty human carotid cadaveric explants (mild stenoses 0-29%, n = 23; moderate stenoses 30-69%, n = 3; severe stenoses 70-99%, n = 2) that included the common, internal and external carotid arteries were integrated into a pulsatile-flow model. Three groups were formed according to the age of the donors (mean 58.8 years; sample SD 15.99 years) and randomized to three test groups: (I) MembraX, n = 9; (II) Xpert bare stent, n = 10; (III) Xpert bare stent with Emboshield protection device, n = 9. Emboli liberated during stent deployment (step A), post-dilatation (step B), and late embolization (step C) were measured in 100 microm effluent filters. When the Emboshield was used, embolus penetration was measured during placement (step D) and retrieval (step E). Late embolization was simulated by compressing the area of the stented vessel five times.
  
  
  RESULTS
  Absolute numbers of particles (median; >100 microm) caught in the effluent filter were: (I) MembraX: A = 7, B = 9, C = 3; (II) bare stent: A = 6.5, B = 6, C = 4.5; (III) bare stent and Emboshield: A = 7, B = 7, C.=.5, D = 8, E = 10. The data showed no statistical differences according to whether embolic load was analyzed by weight or mean particle size. When summing all procedural steps, the Emboshield caused the greatest load by weight (p = 0.011) and the largest number (p = 0.054) of particles.
  
  
  CONCLUSIONS
  On the basis of these limited data neither a membrane stent nor a protection device showed significant advantages during ex vivo carotid angioplasty. However, the membrane stent seems to have the potential for reducing the emboli responsible for supposed late embolization, whereas more emboli were observed when using a protection device. Further studies are necessary and warranted.
authors.affiliation: Department of Radiology, University Hospital, Schleswig-Holstein-Campuskiel, Arnold-Heller-Strasse 9, 24105, Kiel, Germany. muehue@rad.uni-kiel.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Müller-Hülsbeck
authors.forename: Albrecht
authors.initials: A
authors.lastname: Gühne
authors.forename: Michael
authors.initials: M
authors.lastname: Tsokos
authors.forename: Erhard J
authors.initials: EJ
authors.lastname: Hüsler
authors.forename: Silvio R
authors.initials: SR
authors.lastname: Schaffner
authors.forename: Friedrich
authors.initials: F
authors.lastname: Paulsen
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hedderich
authors.forename: Martin
authors.initials: M
authors.lastname: Heller
authors.forename: Thomas
authors.initials: T
authors.lastname: Jahnke
mesh_terms: D000328:Adult; D017130:Angioplasty / Q000379:methods*; D002102:Cadaver; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000601:surgery*; D002533:Cerebral Angiography; D004867:Equipment Design; D006801:Humans; D015607:Stents