The wound healing response after implantation of a drug-eluting stent is impaired persistently in the long term

Abstract

A 70-year-old man underwent stent implantation for right coronary artery (RCA) lesions with a bare metal stent (BMS) and two sirolimus-eluting stents (SES). However, as both the BMS and SES stented sites developed restenosis after 13 months, he underwent target lesion revascularization using directional coronary atherectomy (DCA). On histopathology, the restenosis lesion at the SES-deployed site showed greater inflammation and less re-endothelialization than that at the BMS-deployed site. Three months later, the SES-deployed site developed a second restenosis, in which paclitaxel-eluting stents (PES) were implanted (PES-in-SES), while the BMS-deployed site was restenosis free. Five years later, restenosis was absent in these RCA lesions. However, by optical coherence tomography and/or coronary angioscopy, the PES-in-SES site in the RCA showed poor neointimal coverage over the stent struts and yellowish neointima, suggesting lipid-rich neoatheroma formation, whereas at the BMS site appropriate white neointima formation was observed. Drug-eluting stents still have problems of persistent inflammation, inappropriate neointima formation, and neoatherosclerosis. Although we are now in the era of second generation DESs in which better stent performance would be promising, we should remember that we are obliged to continue to follow-up all patients in whom first generation DESs such as SES or PES have been placed.

Efficacy of Endeavor zotarolimus-eluting stent implantation for the treatment of very late stent thrombosis with late-acquired incomplete stent apposition after sirolimus-eluting stent implantation

“…Suppression of smooth muscle cell infiltration, inappropriate neointimal formation and delayed arterial healing are associated with VLST [4]. The therapy choice for VLST with late-acquired incomplete stent apposition and incomplete neointimal coverage remains unknown.…”

Smart releasing electrospun nanofibers—poly: L.lactide fibers as dual drug delivery system for biomedical application

“…Clinical observation of long-term healing after implant placement indicates that the reendothelialisation process can continue for months. For this reason we wanted to extend the bioavailability of VEGF for as long as possible via stable covalent surface conjugation [23]. In this work we could adapted the methods to be compatible with electrospinning and spraycoating to directly compare the properties of thin film coatings and electrospun nanofibers independently of the fabrication method.…”

Effectiveness and Safety of Biolimus A9™-Eluting stEnt in Patients with AcUTe Coronary sYndrome; A Multicenter, Observational Study (BEAUTY Study)

“…Delayed or absent endothelialization of the stent strut, hypersensitivity or inflammatory reactions to the DES polymer, and the development of neoatherosclerosis within stents with new plaque rupture have been considered as potential causes of late ST occurring with DES. 1 2 3 …”