Polylactide Bioresorbable Scaffolds: From inception to long-term follow-up of first in man studies

Abstract

Since the fi rst balloon angioplasty was performed in the late 1970’s, percutaneous coronary intervention (PCI) has undergone a rapid transformation to become an essential treatment option for coronary artery disease as an alternative to surgery. PCI is now widely accepted across the globe. The advent of bare metal stenting and the landmark BENESTENT and STRESS trials in 1990’s have established bare metal stenting as the second revolution in PCI. This technology provided a solution to acute vessel occlusion by sealing the dissection fl aps and preventing recoil. However, neointimal hyperplasia inside the stent was even more prominent than with angioplasty, necessitating repeat treatment in numerous patients. In 2000, drug-eluting stents were introduced to solve the problem of in-stent restenosis. Both large scale randomised trials and all-comer registries showed excellent results in terms of the need for repeat revascularisation. The introduction of drug-eluting stents was thus dubbed the third revolution in interventional cardiology. However, these new devices created again a new enemy: by interfering profoundly with the healing process, a lack of endothelialization and late persistent or acquired malapposition of the permanent metallic implant became the nidus of late and very late stent thrombosis, without mentioning the hypersensitive reaction mediated by eosinophils that sometimes triggered these catastrophic events. Vasomotion testing demonstrated abnormal vasoconstriction responses to acetylcholine distal to the deployed stent, suggesting that the structure and function of the endothelium remained abnormal.