Please click here to obtain permission to reproduce this image.
Click on image to view larger version.
Figure 1 SEM and Quantitative Analysis of 28-Day Rabbit Iliac Artery Stent Implants
Scanning electron microscopy (SEM) photographs and quantitative analysis of rabbit iliac arteries implanted with overlapping sirolimus-eluting stents (SES), sirolimus-eluting stents plus estradiol (SES+ED), bare-metal stents (BMS), and Cypher drug-eluting stents (CDES). The dashed lines indicate boundaries of stent overlap. (A) En-face examination demonstrates near-complete endothelial coverage of SES, SES+ED, and BMS, with rare areas of exposed struts confined to the overlap region. However, there is marked absence of intact endothelium over stent struts in CDES, especially in the overlapping segment. High magnification of the nonoverlapping and overlapping sites (box) shows that the endoluminal surface of SES, SES+ED, and BMS remains covered by endothelium with very few inflammatory cells. However, CDES show widespread areas of exposed stent struts and incompletely endothelialized lumen with fibrin, adherent heterophils/eosinophils, macrophages, and platelets in the vicinity of stent struts. (B) Quantitative analysis of endothelial coverage: the SES, SES+ED, and BMS demonstrated greater endothelialization than CDES at both the nonoverlapping and overlapping segments of the stent. For CDES, there is also significantly less endothelialization in overlapping as compared with nonoverlapping areas, which does not occur in the ISAR (Individualizable drug-eluting stent System to Abrogate Restenosis) stents. *p = 0.003 versus SES, SES+ED, BMS.  p = 0.02 versus nonoverlapping CDES.
|
