Inhibition of platelet deposition on polytetrafluoroethylene grafts by antiplatelet agents.

The effects of ibuprofen (Motrin), dipyridamole (Persantine), and prostacyclin on the deposition of platelets on polytetrafluoroethylene grafts (5.5 cm long, 4 mm internal diameter implanted into both femoral arteries of 21 dogs) were studied by harvesting autologous platelets, labeling them with 51Cr, and reinjecting them 15 minutes before cross-clamping. Arterial flow was adjusted to 65 ml/min and monitored continuously. Ibuprofen (12.5 mg/kg) and dipyridamole (2.5 mg/kg) were each administered as a single intravenous injection in four dogs (eight grafts) and five dogs (10 grafts), respectively. Prostacyclin (50 ng/kg/min) was administered by continuous intravenous infusion in five dogs (10 grafts). Seven dogs (14 grafts) served as controls. Grafts were removed 2 hours after implantation, and radioactivity (counts per 10 minutes) was determined in four segments of each graft (including both anastomoses) with a gamma-counter. Counts were averaged for each group of dogs. Significance was calculated by the Student t test. Platelet deposition in control dogs averaged 10,033.9 +/- 1134.2 SE; that in prostacyclin-treated dogs averaged 2513.7 +/- 276 SE (p less than 0.001); that in ibuprofen-treated dogs averaged 5453.4 +/- 1336.3 SE (p = 0.02); that in dipyridamole-treated dogs averaged 11,213.7 +/- 1632.5 SE (p = 0.55). These data demonstrate the effectiveness of prostacyclin and ibuprofen in reducing platelet deposition on polytetrafluorethylene grafts in dogs.