[Limitations and usefulness of coronary stents in diverse clinical conditions. Long-term course]. / Limiti e utilità degli stent coronarici nelle varie condizioni cliniche. Decorso a lungo termine.

Since the introduction of balloon angioplasty, the acceptance and widespread application of coronary stents is the most important advance in interventional cardiology. The option of bail-out stenting has liberated interventionalists from the restrains of surgical stand-by. It has also allowed more aggressive balloon angioplasty and better short- and long-term results. This progress was enabled by improvements in deployment technique and antiplatelet therapy preventing most of the vexing problems of subacute stent thrombosis. Whereas initial registries and randomized trials focused on specific narrow patient populations, the clinical indications are broadening based on the results of new clinical trials that have focused on expanding populations, such as restenotic lesions, small vessels, total chronic occlusions, saphenous vein grafts stenoses, and acute ischemic syndromes. Despite this progress, a solution to the problem of in-stent restenosis, although less frequent than after balloon angioplasty alone, is still pending. In this review, we will discuss the process of restenosis which is the main indication for the use of stents, then we will analyze the application of stents in some particular clinical and anatomical situations and finally we will focus on in-stent restenosis which is the main limitation for stenting.