title: Improved blood compatibility of a stent graft by combining heparin coating and abciximab.
abstract: The aim of this study was to assess the combined effect of heparin coating of a stent graft and administration of abciximab, on platelet and coagulation activity in vitro.
  
  
  METHODS
  Stent grafts with an expanded polytetrafluoroethylene (ePTFE) membrane interfoliated between two stents were deployed in tubings to form Chandler loops. Fresh human blood with a low concentration of heparin and various doses of abciximab was rotated for 1 h, then collected and used for measurements of platelets, thrombin-antithrombin complex (TAT), CD11b, complement and contact activation of coagulation. In the first set of experiments, all stent grafts were heparin coated. There were three study groups: Group 1a (no abciximab, n=5); Group1b (abciximab in a concentration of 3.3 microg/ml, n=5); Group 1c (abciximab in a concentration of 8.3 microg/ml, n=5). In the second set of experiments, the concentration of abciximab was 3.3 microg/ml. There were three study groups: Group 2a (untreated stent grafts, n=4); Group 2b (heparin-coated stent grafts, n=4); Group 2c (heparin-coated PVC tubings with no stent grafts, n=4).
  
  
  RESULTS
  In the first set of experiments, there was a significant reduction in platelet count in Group 1c compared to Group 1a and Group 1b. There was a significant reduction in TAT in Group 1b and Group 1c as compared to Group 1a. In the second set of experiments, TAT was reduced in Group 2b and Group 2c compared to Group 2a. Contact activation was lowered in Group 1b and Group 1c as compared to Group 1a for both FXIa-AT (0.088 and 0.088 vs. 0.115) and FXIIa-AT (0.12 and 0.12 vs. 0.19).
  
  
  CONCLUSIONS
  Heparin coating of a stent graft was shown to improve blood compatibility and this was further enhanced by addition of abciximab.
authors.affiliation: Department of Cardiology, University Hospital, Orebro, S-701 85, Sweden. kjeld.christensen@orebroll.se
authors.forename: Kjeld
authors.initials: K
authors.lastname: Christensen
authors.forename: Rolf
authors.initials: R
authors.lastname: Larsson
authors.forename: Håkan
authors.initials: H
authors.lastname: Emanuelsson
authors.forename: Graciela
authors.initials: G
authors.lastname: Elgue
authors.forename: Anders
authors.initials: A
authors.lastname: Larsson
mesh_terms: D000077284:Abciximab; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D000925:Anticoagulants / Q000494:pharmacology; D001777:Blood Coagulation / Q000187:drug effects*; D001792:Blood Platelets / Q000187:drug effects*; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000494:pharmacology*; D015539:Platelet Activation / Q000187:drug effects; D010976:Platelet Count; D011138:Polytetrafluoroethylene / Q000737:chemistry / Q000494:pharmacology; D015607:Stents
chemical_list: D000911:Antibodies, Monoclonal; D000925:Anticoagulants; D020099:Coated Materials, Biocompatible; D007140:Immunoglobulin Fab Fragments; D011138:Polytetrafluoroethylene; D006493:Heparin; D000077284:Abciximab