title: Safety and biocompatibility of a novel self-expanding nitinol carotid stent with hybrid cell design in a porcine model of neointimal hyperplasia.
abstract: BACKGROUND
  Stent design may influence the outcomes, suggesting that adverse event rates vary according to free cell area and cell design. Open cell design technology of self-expandable stents, dedicated for carotid revascularisation has better deliverability, although closed cell technology is expected to cause fewer thromboembolic events.
  
  
  OBJECTIVE
  To evaluate the feasibility and vascular response of novel, hybrid cell, self-expandable nitinol stents (MER®, Balton, Poland) implanted into porcine carotid arteries. Hybrid cell design combines open and closed cell technology.
  
  
  METHODS
  All tested stents were implanted with 10% overstretch into 10 carotid segments of Polish domestic pigs. Control angiography was obtained immediately before and after vascular interventions as well as 28 days after the procedure. Thereafter, animals were sacrificed, and the treated segments were harvested and evaluated in the independent histopathology laboratory.
  
  
  RESULTS
  All stents were easily introduced and implanted, showing good angiographic acute outcome. At 28 days, in the angiography, all vessels were patent with no signs of thrombi or excessive neointimal formation, with the late lumen loss of -0.11 ± 0.3 mm and percentage diameter stenosis 10.18 ± 8.1%. There was a 10% increase in the vessel reference diameter when compared to baseline (4.57 ± 0.5 vs. 4.96 ± 0.3 mm, p < 0.01). In the histopathology, mean area stenosis was 17.4% and mean intimal thickness was 0.20 mm. At histopathology, the mean injury, inflammation, and fibrin scores were low. Endothelialisation was complete in all stents, and neointimal tissue appeared moderately mature as shown by the moderate mean neointimal smooth muscle score. Nonetheless, histopathology shows one stent affected by peri-strut granulomas and one stent affected by marked mineralisation.
  
  
  CONCLUSIONS
  The novel Polish self-expandable nitinol carotid stent with hybrid cell technology shows optimal biocompatibility and a vascular healing profile, and therefore may be introduced for first-in-man application.
authors.forename: Adam
authors.initials: A
authors.lastname: Janas
authors.affiliation: Center for Cardiovascular Research and Development, American Heart of Poland SA, Katowice. kpmilewski@gmail.com.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Milewski
authors.forename: Piotr P
authors.initials: PP
authors.lastname: Buszman
authors.forename: Przemysław
authors.initials: P
authors.lastname: Nowakowski
authors.forename: Michał
authors.initials: M
authors.lastname: Jelonek
authors.forename: Bartłomiej
authors.initials: B
authors.lastname: Orlik
authors.forename: Agata
authors.initials: A
authors.lastname: Krauze
authors.forename: Stefan
authors.initials: S
authors.lastname: Samborski
authors.forename: Diane
authors.initials: D
authors.lastname: Beaudry
authors.forename: Guy
authors.initials: G
authors.lastname: Lecelrc
authors.forename: Marek
authors.initials: M
authors.lastname: Król
authors.forename: Jean Martin
authors.initials: JM
authors.lastname: Lapointe
authors.forename: Wojciech
authors.initials: W
authors.lastname: Wojakowski
authors.forename: Anna
authors.initials: A
authors.lastname: Turek
authors.forename: Radosław S
authors.initials: RS
authors.lastname: Kiesz
authors.forename: Paweł E
authors.initials: PE
authors.lastname: Buszman
mesh_terms: D000497:Alloys / Q000009:adverse effects*; D017130:Angioplasty; D000818:Animals; D002339:Carotid Arteries / Q000473:pathology / Q000601:surgery*; D016893:Carotid Stenosis / Q000601:surgery; D006822:Hybrid Cells; D006965:Hyperplasia / Q000209:etiology / Q000473:pathology; D008422:Materials Testing; D023421:Models, Animal; D058426:Neointima / Q000209:etiology* / Q000473:pathology; D061214:Patient Safety; D011474:Prosthesis Design / Q000009:adverse effects; D015607:Stents / Q000009:adverse effects*; D034421:Sus scrofa
chemical_list: D000497:Alloys; C013616:nitinol