Stent, the Saxon sobriquet, is a monosyllabic moniker for the strutted savior of the disease-ravaged coronary artery. Surgery proved to the world that crippling coronary artery disease could be treated but not everyone wanted or warranted an operation. A less traumatic option came from tackling the problem from the inside out but angioplasty was troubled by cave-in. In response, a 2000 year-old mining concept was applied to arteries. Supports for sink shafts became struts for arteries. In truth, the idea was used before the development of angioplasty to prevent sutures attaching two arteries from being tied too tight.(1) When a cave-in could be prevented, angioplasty became safer. Adoption of stents as an addition to angioplasty was rapid and almost universal. But, as each difficult artery fell, the next one loomed larger and the stents seemed too thick, too bulky, too stiff or too weak. They were too likely to renarrow, too hard to see on X-ray and they lasted too long. Despite a designer stent for every occasion, none overcame the fact that they were made of metal. Thus was born the idea of a stent that would be absorbed by the body like stitches that didn't have to be removed. Once it was gone, what was left would be just the artery but one that is reformed.
There have been some very good ideas for stents that get absorbed by the body after placement. In amazing feats of engineering, they could get where they needed to go, give the support that was needed to prevent cave-in and just fade away. The question posed was how they compare to the metal versions that are used routinely.
In several hospitals in the Netherlands, about 2000 people who were having something done to their coronary arteries agreed to have a reabsorbable stent if they were chosen. The ease with which the stent could be used, problems with its placement and how it held up long term were recorded. Generally, the reabsorbable version was a little harder to place. Once in place, both the routinely used version of a stent and the reabsorbable one held up about the same with one major difference. When the test version ran aground, it did so in the least desirable manner possible. It clotted.
Impact and analysis
The observations from this study are quite a blow to the stent being studied. It is not the end of an idea but it places a hurdle before similar stents that will come after. The observations made through the development of this stent may be re-examined as part of a post-mortem to see why a clot was a more frequent mode of failure than with the standard metal version. In the interim, this will have no major impact on the current model for when and where a stent is the right treatment option.
Keywords: Stent, Thrombosis, Coronary Artery Disease, Cardiovascular Disease
1. Hall Rj Fau - Khouri EM, Khouri Em Fau - Gregg DE, Gregg DE. Coronary-internal mammary artery anastomosis in dogs. Surgery. 1961;50(0039-6060 (Print)):560-7.