title: Radionuclide study of platelets and prosthetic interactions: external versus specimen quantitation.
abstract: Twenty-nine New Zealand white rabbits were allocated to undergo insertion of either polytetrafluoroethylene (PTFE) (n = 22) or microporous silicone rubber (SR) (n = 7), 3-mm diameter, 10-mm long aortic grafts. Animals with PTFE grafts received aspirin (ASA) 10 mg/kg/d and dipyridamole (DPM) 10 mg/kg/d (n = 11) or placebo (n = 11). Autologous In-111-oxine-labeled platelets were reinfused on reestablishment of blood flow through the graft. Using gamma camera images, an external graft platelet accumulation index (E-GPAI) was calculated as the In-111 activity in the graft area to the reference aorta at 24, 48, and 72 hours post implantation. Mean E-GPAI +/- SEM values for the ASA/DPM (n = 4) and control groups (n = 7) were 1.13 +/- 0.16 and 1.34 +/- 0.05 (NS) at 24 hours, 1.20 +/- 0.16 and 1.33 +/- 0.07 (NS) at 48 hours, and 1.38 +/- 0.07 and 1.35 +/- 0.10 (NS) at 72 hours, respectively. A similar internal graft platelet accumulation index (I-GPAI) was constructed based on In-111 activity in excised grafts and reference aorta measured in a scintillation counter. Mean I-GPAI +/- SEM values for the PTFE ASA/DPM (n = 9) and control groups (n = 8) at 48 hours post implantation were 43.1 +/- 2.7 and 216.8 +/- 73.9 (P = 0.05), respectively. I-GPAI values for the SR grafts were 192.5 +/- 43.1.
  
  
  CONCLUSIONS
  The E-GPAI was not sensitive enough to demonstrate the effect of antiplatelet medication on platelet accumulation on the PTFE grafts.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Surgery, Harbor-UCLA Medical Center, Torrance 90509.
authors.forename: A G
authors.initials: AG
authors.lastname: Nordestgaard
authors.forename: C S
authors.initials: CS
authors.lastname: Marcus
authors.forename: S E
authors.initials: SE
authors.lastname: Wilson
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000502:physiology*; D001807:Blood Vessel Prosthesis / Q000009:adverse effects; D005069:Evaluation Studies as Topic; D007205:Indium Radioisotopes; D008297:Male; D010974:Platelet Aggregation; D011817:Rabbits; D013927:Thrombosis / Q000209:etiology
chemical_list: D007205:Indium Radioisotopes