[Quantitative study of platelet deposition on expanded polytetrafluoroethylene grafts using 111indium-labeled
1Second Department of Surgery, Yamagata University School of Medicine, Japan.
Abstract:
The count of platelets deposited on expanded polytetrafluoroethylene grafts (2 cm long, 3 mm internal diameter, implanted into thoracic aortae of 59 rabbits) was measured using 111Indium-labeled autologous platelets. The changes due to the time courses after implantation, the effect of aspirin and the differences of the platelet deposition on the thrombus and thrombus free surface were studied. In non-treated grafts, platelet deposition on the thrombus free surface was significantly and repeatedly decreased on the 3rd (42.3 +/- 16.6 X 10(4)/mm2, mean +/- S.D.), 9th (17.7 +/- 5.3 X 10(4)/mm2), and 30th (6.8 +/- 3.2 X 10(4) mm2) days after the implantation (p less than 0.05). In treated grafts, platelet deposition on the thrombus free surface was significantly inhibited by aspirin on the 3rd day (20.5 +/- 8.4 X 10(4)/mm2) after implantation (p less than 0.03), while significant inhibition of platelet deposition by aspirin was not noted on the 9th (13.4 +/- 3.8 X 10(4)/mm2) and 30th (13.1 +/- 4.5 X 10(4)/mm2) days after the implantation. Platelet deposition on the thrombus was not inhibited by aspirin. (3600 +/- 2400 X 10(4)/mm2, non-treated grafts. 3500 +/- 520 X 10(4)/mm2, treated grafts). It is concluded that administration of aspirin is necessary immediately after implantation, and its effect is not noted at the time when the deposition of the platelet decreased, and the effect of aspirin cannot be expected in tissues where easy platelet aggregation occurs.
