Influence of stent expansion states on platelet deposition in an extracorporeal porcine arteriovenous shunt model using a multichannel perfusion chamber

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.

Immediate and Long Term Outcome of Single Long Stent for Long Complex Coronary Artery Stenosis Compared to Multiple Conventional Stent

Coronary stenting for long complex lesion is effective but associated with complication. We compared the results of stenting between with multiple conventional stenting group (group A) and with single long stenting group (group B). Fifty patients were prospectively and randomly enrolled: 25 patients for each group. Each group showed no significant differences of clinical characteristics. One patient died of heart failure in each group, not associated with the procedure itself. One patients had cerebrovascular accident in each group. Five patients had major bleeding (2, group A; 3, group B). Angiographic success rate was 100% in each group and procedural success rate was 96% and 100% in group A and B, respectively. Angiographic and clinical restenosis rate at 6 months follow-up were 60%, 36% in group A and 65%, 44% in group B, respectively (p=S). Multivariate analysis showed that several factors affected the angiographic restenosis rate as follows; a) male gender (M:F=76.9%:25.0%, P<0.001), b) AMI (AMI:stable angina pectoris=72.7%:66.7%, P<0.001), c) lesion length d) residual stenosis. In conclusion, there were no statistical differences of restenosis and complication rate between the two groups. Our data support single long stenting is acceptable and economically more favorable for long diffuse lesion, compared to multiple conventional stenting.