title: Antiplatelet therapy and vascular grafts. Studies in a baboon ex vivo shunt.
abstract: Antiplatelet therapy is currently recommended in an effort to improve patency rates of small-caliber vascular grafts. The effect of aspirin and heparin on acute platelet deposition was studied in a baboon ex vivo shunt. Two grafts, expanded polytetrafluoroethylene and knitted Dacron, were exposed to a flow rate of 25 mL/min after administration of aspirin or heparin. Indium 111-labeled platelet uptake by the grafts was determined over 2 1/2 hours. The amount of platelet deposition in the treated groups was significantly less than that of controls after 2 1/2 hours. There was no difference between the aspirin and heparin groups. The finding that heparin inhibited platelet deposition to a degree comparable with aspirin suggests that it may not be necessary to start antiplatelet therapy preoperatively. Intraoperative systemic heparinization will provide sufficient inhibition of platelet deposition. A protocol for perioperative antiplatelet therapy is outlined.
mesh_terms: D000818:Animals; D001241:Aspirin / Q000494:pharmacology*; D001760:Bleeding Time; D001777:Blood Coagulation / Q000187:drug effects; D001792:Blood Platelets / Q000187:drug effects*; D001807:Blood Vessel Prosthesis; D006083:Graft Occlusion, Vascular / Q000097:blood / Q000517:prevention & control*; D006493:Heparin / Q000494:pharmacology*; D008297:Male; D010215:Papio; D011093:Polyethylene Terephthalates; D011138:Polytetrafluoroethylene; D013929:Thromboxane B2 / Q000097:blood
chemical_list: D011093:Polyethylene Terephthalates; D013929:Thromboxane B2; D011138:Polytetrafluoroethylene; D006493:Heparin; D001241:Aspirin