Detection of platelet deposition at the site of peripheral balloon angioplasty using indium-111 platelet scintigraphy.

Restenosis after balloon angioplasty may be mediated through platelet deposition at the site of arterial dilatation. The purpose of this study was to determine whether platelet deposition at the site of dilatation could be detected using indium-111 platelet scintigraphy. Fifteen patients, aged 60 +/- 9 years, with iliac or femoral (n = 12), renal artery (n = 2) or distal aortic (n = 1) stenoses were studied. All patients received intravenous heparin at the time of dilatation. Labeled platelets containing 471 +/- 65 muCi indium-111 were injected 0.25 to 4 hours after dilatation and 1 to 24 hours after imaging. In 11 of 12 patients with iliac and femoral dilatations, focal uptake was demonstrated at the angioplasty site. In 4 patients (2 patients with renal, 1 patient with iliofemoral, and 1 with distal aortic stenoses), uptake at the dilatation sites was not detected. This preliminary study indicates that despite intravenous heparin, platelets accumulate at sites of balloon dilatation. Platelet scintigraphy may be useful in predicting sites of future narrowing after angioplasty and may be used to test the efficacy of antiplatelet therapy in retarding restenosis.