title: Thrombogenicity of a new injectable biocompatible elastomer for aneurysm exclusion, compared to expanded polytetrafluoroethylene in a human ex vivo model.
abstract: OBJECTIVE
  Customized aortic repair (CAR) is a new concept for endovascular aortic aneurysm repair in which a non-polymerised elastomer is injected to fill the aneurysm sac around a balloon catheter. Amongst other variables, the thrombogenicity of the elastomer should be tested, before further clinical experiments can take place. The aim of this human ex vivo study was to measure the thrombogenicity of the elastomer and to compare it to expanded polytetrafluoroethylene (ePTFE).
  
  
  METHODS
  In a validated ex vivo model, non-anticoagulated blood was drawn from the antecubital veins of 10 healthy donors with a 19-gauge needle. It was drawn through elastomer tubes and through ePTFE Gore-Tex vascular grafts, both 60 cm long and with an inner diameter of 3 mm.
  
  
  METHODS
  Fibrinopeptide A (FPA) and P-selectin expression was measured in blood samples, collected at the end of the grafts. After the experiments, the deposition of platelets and fibrin onto the grafts was visualised by scanning electron microscopy.
  
  
  RESULTS
  For these graft types, a progressive increase in FPA production was observed in time. No significant difference was observed between the elastomer and ePTFE grafts (p > 0.05). No increase in P-selectin expression, and thereby no platelet activation, was observed in the perfusate of either grafts (p > 0.05). By scanning electron microscopy, numerous platelet aggregates were observed on the ePTFE grafts, whereas just a few adhered platelets and no aggregates were observed in the elastomer grafts.
  
  
  CONCLUSIONS
  The elastomer in its current formulation has a low thrombogenicity, comparable to ePTFE, making it an ideal substance for endovascular aneurysm sac filling. Further research should clarify the feasibility of CAR in vivo.
authors.affiliation: Department of Surgery, Bronovo Hospital, The Hague, The Netherlands. tjvdsteenhoven@bronovo.nl
authors.forename: T J
authors.initials: TJ
authors.lastname: van der Steenhoven
authors.forename: W M P F
authors.initials: WM
authors.lastname: Bosman
authors.forename: C
authors.initials: C
authors.lastname: Tersteeg
authors.forename: M J
authors.initials: MJ
authors.lastname: Jacobs
authors.forename: F L
authors.initials: FL
authors.lastname: Moll
authors.forename: P G
authors.initials: PG
authors.lastname: de Groot
authors.forename: J M M
authors.initials: JM
authors.lastname: Heyligers
mesh_terms: D000328:Adult; D001014:Aortic Aneurysm / Q000097:blood / Q000601:surgery / Q000628:therapy*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D004129:Dimethylpolysiloxanes / Q000008:administration & dosage* / Q000009:adverse effects; D057510:Endovascular Procedures / Q000009:adverse effects / Q000295:instrumentation*; D005337:Fibrin / Q000378:metabolism; D005344:Fibrinopeptide A / Q000378:metabolism; D006801:Humans; D007267:Injections; D008297:Male; D008855:Microscopy, Electron, Scanning; D019007:P-Selectin / Q000097:blood; D010973:Platelet Adhesiveness; D011138:Polytetrafluoroethylene; D011474:Prosthesis Design; D012826:Silicone Elastomers / Q000008:administration & dosage* / Q000009:adverse effects; D013927:Thrombosis / Q000097:blood / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D013997:Time Factors; D055815:Young Adult
chemical_list: D004129:Dimethylpolysiloxanes; D019007:P-Selectin; C546937:SELP protein, human; D012826:Silicone Elastomers; D005344:Fibrinopeptide A; C013830:baysilon; D005337:Fibrin; D011138:Polytetrafluoroethylene