The first improvement consisted in the introduction of nitinol self-expanding stents.
This technology allowed an initial improvement of clinical performances, but the first generation of nitinol stents demonstrated a relatively high rate of fractures.
Better knowledge of arterial biomechanics and advances in technology allowed to propose a second generation of nitinol stents with improved flexibility, which decreased the rates of fracture. In-stent restenosis related to neointimal hyperplasia has also led to the development of new concepts to improve patency rates after stenting: drug-eluting stents (coated-stents), biodegradable stents, and covered stents.
These technologies will help to treat more complex lesions in the future, but we are still waiting for results of ongoing studies.