Limited data are available about incomplete stent expansion (SE) on platelet deposition (PD). We examined PD following different SE using an extracorporeal porcine arteriovenous shunt model to which a perfusion chamber with four parallel silastic tubes were connected. Blood flow was set at a 20 and 100 mL/min in 1.8 and 3.1 mm diameter tubes, respectively. P154 stents were deployed completely (Group A, n=15) or incompletely (Group B, n=15) in 1.8 mm (n=13) and 3.1 mm (n=17) tubes. 51Cr-labelled platelet autologous blood was injected 1 hr before the perfusion. After 15 min-perfusion, the testing tubes were assessed for radioactivity counts. In-stent cross sectional area was measured by intravascular ultrasound. There was a significant difference in PD between group A and B regardless of channel size (118+/-18.4 vs 261.4+/-52.1 pits x 10(6)/cm2, p<0.05). With adjusted shear rate and similar stenosis, PD was similar in both tubes. In smaller 1.8 mm tubes, a stenosis as subtle as 10% was associated with a significant PD difference (226.1+/-20 vs 112.9+/-20.5 plts x 10(6)/cm2, p<0.005). This model enabled a repetitive, simultaneous comparison of PD following different SE states. It seems that the quality of SE remains crucial in smaller channels.
Animal ; Arteriovenous Shunt, Surgical ; Extracorporeal Circulation ; Male ; Models, Animal ; Perfusion ; Platelet Activation* ; Stents/adverse effects* ; Swine ; Thrombosis/etiology*