title: Preclinical evaluation of the thrombogenicity and endothelialization of bare metal and surface-coated neurovascular stents.
abstract: OBJECTIVE
  Stent-assisted coiling is routinely used for the endovascular treatment of complex or wide-neck intracranial aneurysms. However, in-stent thrombosis, thromboembolic events, and ischemic complications remain a major concern associated with stent implants. Therefore, a novel low-profile neurovascular stent with a bare metal surface was investigated with regard to thrombogenicity and endothelialization and compared with the same stent coated with albumin or heparin.
  
  
  METHODS
  The bare metal and heparin- or albumin-coated stents were loaded in heparin-coated tubing, which was then filled with heparinized human blood (n = 5) and circulated at 150 mL/min and 37°C for 60 minutes. Before and after circulation, measurement of various inflammation and coagulation markers and scanning electron microscopy were performed. Endothelialization of the stents was investigated in an in vitro model including human umbilical vascular endothelial cells.
  
  
  RESULTS
  Our results showed that platelet loss and platelet activation and activation of the coagulation cascade, which are induced by the bare metal stents, were significantly reduced by heparin or albumin coating. Adverse effects on erythrocytes, leukocytes, and the complement cascade were not induced by the bare metal or coated stents. Moreover, the bare metal and albumin-coated stents showed good endothelialization properties.
  
  
  CONCLUSIONS
  Albumin and heparin coatings clearly improve the thrombogenicity of the stents and thus may represent fundamental progress in the treatment of intracranial aneurysms. Moreover, preclinical evaluation of neurovascular stents under physiologic conditions supports and accelerates the development of more biocompatible neurovascular stents.
authors.affiliation: From the Department of Thoracic, Cardiac and Vascular Surgery (S.K., B.N., J.K., N.P., M.A.-A., H.P.W.), Clinical Research Laboratory, University Hospital Tuebingen, Tuebingen, Germany stefanie.krajewski@uni-tuebingen.de.
authors.forename: S
authors.initials: S
authors.lastname: Krajewski
authors.affiliation: From the Department of Thoracic, Cardiac and Vascular Surgery (S.K., B.N., J.K., N.P., M.A.-A., H.P.W.), Clinical Research Laboratory, University Hospital Tuebingen, Tuebingen, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Neumann
authors.affiliation: From the Department of Thoracic, Cardiac and Vascular Surgery (S.K., B.N., J.K., N.P., M.A.-A., H.P.W.), Clinical Research Laboratory, University Hospital Tuebingen, Tuebingen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Kurz
authors.affiliation: From the Department of Thoracic, Cardiac and Vascular Surgery (S.K., B.N., J.K., N.P., M.A.-A., H.P.W.), Clinical Research Laboratory, University Hospital Tuebingen, Tuebingen, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Perle
authors.affiliation: From the Department of Thoracic, Cardiac and Vascular Surgery (S.K., B.N., J.K., N.P., M.A.-A., H.P.W.), Clinical Research Laboratory, University Hospital Tuebingen, Tuebingen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Avci-Adali
authors.affiliation: Acandis GmbH & Co KG (G.C.), Pforzheim, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Cattaneo
authors.affiliation: From the Department of Thoracic, Cardiac and Vascular Surgery (S.K., B.N., J.K., N.P., M.A.-A., H.P.W.), Clinical Research Laboratory, University Hospital Tuebingen, Tuebingen, Germany.
authors.forename: H P
authors.initials: HP
authors.lastname: Wendel
mesh_terms: D000418:Albumins; D057510:Endovascular Procedures / Q000009:adverse effects / Q000295:instrumentation*; D006493:Heparin; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D008670:Metals; D015539:Platelet Activation; D015607:Stents / Q000009:adverse effects; D013927:Thrombosis / Q000209:etiology
chemical_list: D000418:Albumins; D008670:Metals; D006493:Heparin