The kinetics and quantitation of platelet deposition on control (CPC) and heparin-bonded polyurethane angio-catheter (HBPC) with indium-111 labeled platelets in a dog model

The dynamics of platelet deposition on CPC and HBPC was evaluated with In-111 labeled platelets (In-PLT) with a computerized gamma camera (CGC). Ten non-heparinized dogs (18-25 kg) were catheterized in both femoral arteries with 10 cm of CPC and HBPC (5 Fr., Cordis, Inc.) 24 hours post-injection of 300-420 microcuries of In-PLT, and imaged for 3 hours with gamma camera. The regional platelet deposition on three segments of catheters and puncture site was determined. The catheters were harvested and radioactivity on the catheter segments (proximal: PROX, middle: MID, distal: DIST and puncture site: PS) of both was determined. From the platelet count in blood, radioactivity in blood and segments of catheters, adjacent artery and area of artery and catheter, the platelet-density [X10(3)] (mean +/- S.D.) on catheter and artery were calculated and tabulated: (table; see text) The large standard deviation of retained platelets is due to embolization. The platelet-density and regional counts on catheter segments were lower in the HBPC than CPC. The rate of platelet-deposition was lower in the HBPC than CPC. Most of the thrombi were lost during pullout of the catheter. Both in vivo (dynamic) and in vitro studies were necessary for evaluation of CPC thrombogenicity.