A novel mouse model of stenting after 28 and 90 days. We conﬁrm in this study the importance of IL-1 in vascular response to stenting, and validate our new model, by observing a reduction in in-stent restenosis after deploying stents in IL-1 receptor (IL-1R1)-deﬁcient mice. 2. Methods 2.1 Animals IL-1R12/2 mice (stock no. 003245) and their genetically matched wild- type strain, IL-1R1þ/þ (stock no. 000664), were obtained from the Jackson Laboratories. Animals were housed in a controlled environ- ment with a 12 h light/dark cycle at 228C. All experiments were per- formed in accordance with the UK legislation under the 1986 Animals (Scientiﬁc Procedures) Act, and approval was granted by the University Ethics Review Board. The investigation conforms with the Guide for the Care and Use of Laboratory Animals published 39 by the US National Institutes of Health (NIH Publication No. 85-23, revised 1996). 2.2 Stent design A self-expanding coil stent made from nitinol wire (Figure 1A) con- tained within a hollow tubular steel introducer catheter (custom made by Brivant Medical Engineering, Galway, Ireland) was used throughout this study. To deploy, the introducer is retracted over a pusher allowing the stent to deploy to a coil length of 3 mm and diam- eter of 1 mm (Figure 2A). As the stent exits the catheter eccentrically, the tip was blunted with a laser welded bead and a straight ‘leg’ added to act as a stabilizing strut lying against the vessel wall during deploy- ment, giving the stent a total length of 4 mm. 2.3 Mouse aortic stent procedure The stent is placed into the abdominal aorta via femoral access (Figure 2B). Mice (27 – 35 g; 4 – 6 months old) were pre-treated for Figure 1 The stent design. Scale shows 1 mm (A). The femoral vein and artery are controlled proximally by slings and ligated distally (B). Making an arteriotomy (C ). The stent catheter is inserted into the femoral artery (D) and slowly advanced (E) into the abdominal aorta. Scale bar represents 350 mm.