Hoop dreams. Stents without restenosis.

Spanning ribs enable canoes and massive sailing ships to float and withstand the battering of the seas. Bronze-age huts were supported by massive wooden hoops embedded in the walls, and the great cathedrals of Europe rose only by virtue of innovative buttress supports. Endovascular stents were designed with the expectation that they would similarly buttress the collapsible artery against deforming stress with the hope that they might break the vicious cycle of arterial stenosis, intervention, and restenosis. As these devices stretch vessels to their greatest extent, they represent the extreme of the notion that “bigger is better.” This prevailing paradigm in interventional cardiology holds that relative restenosis is minimized by maximization of the initial lumen diameter; the larger the diameter is immediately after any form of angioplasty, the greater is the degree but the less is the impact of luminal encroachment from elastic recoil, thrombosis, intimal hyperplasia, and matrix remodeling.1 The attraction of this paradigm arises in part from frustration with attempted control of the vascular response to injury. To date, even the most promising pharmacological agents have failed to stem the tide of restenosis, and the most sophisticated of mechanical interventions have, if anything, exacerbated the problem. Only the simplest approach beyond balloon angioplasty, endovascular stenting, now appears to offer some relief,2 3 4 5 yet even these devices are limited by the vascular counterreaction they elicit. If the “bigger is better” paradigm holds true, the only recourse is to use larger stents expanded to their maximal extent. Furthermore, if size alone dictates restenosis, no single stent design should be superior to any other. Extensive experimental data, however, suggest that the pathobiological response to implantation of an endovascular device involves a complex interplay among design, material, and deployment technique. Reconciling clinical dogma with experimental observations will require …