Experimental study on hemocompatibility of domestic silicone-covered stent

Objective: To evaluate the hemocompatibility of domestic silicone-covered stent in the iliac arteries of canine model. Methods: Eighteen domestic stents were placed in iliac arteries of 9 adult dogs after larger balloon PTA, which included 10 silicone-covered stents and 8 bare stents for control. DSA was performed at 1, 4, 12 weeks after stent implantation in the iliac arteries of two groups to observe the outcomes of patency or restenosis. Animals were then euthanized isolating and staining the stented arteries with hematoxylin and eosin for histological examination. Finally, the acute thrombosis, reendothelialization and the neointimal proliferation of both covered and bare stents were quantified on histological cross-section. Results: All bare stents were patent in 12 weeks, but two silicone-covered stents were occluded at 4, 12 week respectively (patent rate was 80%). Stented vascular stenosis rate was averaging 72.3% at 12 week in covered stents and 36.7% in bare stents. Conclusions: The hemocompatibility of silicone-covered stents is not better than that of bare stents. Silicone appears to be inert in this experimental application. (authors)