Prevention of platelet deposition by ibuprofen and calcium dobesilate in expanded polytetrafluoroethylene vascular grafts

This study was designed to evaluate the plateletinhibiting effect of a new drug, calcium dobesilate, and to compare its efficacy to the known antiplatelet agent, ibuprofen. Five centimeter long expanded polytetrafluoroethylene grafts (internal diameter 4 mm) were used to replace 48 carotid arteries in 24 dogs. Autologous platelets were labeled with indium-111-labeled tropolone and reinjected into each animal 24 hours before operation. Six animals received an intravenous placebo, six received 12.5 mg/kg of intravenous ibuprofen, six received 100 mg/kg of intravenous calcium dobesilate, and six received 200 mg/kg of intravenous calcium dobesilate before cross-clamping. The grafts were removed after 3 hours, and radioactivity was measured and platelet deposition calculated. The results have indicated that preoperative administration of ibuprofen and calcium dobesilate in this animal model significantly diminishes early platelet deposition. Calcium dobesilate appears to be a dose-dependent, highly effective antiplatelet agent.