title: Scanning electron microscopy analysis of luminal inflammation induced by different types of coronary stent in an animal model.
abstract: There is histological evidence that drug-eluting stents are associated with delayed endothelialization and a persistent inflammatory state. Moreover, clusters of inflammatory cells have been observed on luminal surfaces by scanning electron microscopy. With the aim of quantifying this inflammatory response, we implanted one bare-metal stent and two drug-eluting stents containing different doses of vinblastine embedded in the same polymer into the coronary arteries of 12 domestic pigs. The density of inflammatory cells in a representative area (100 x 100 μm) was quantified at 3 and 7 days. Endothelialization was more complete in bare-metal stents than in drug-eluting stents at both 3 days (P=.016) and 7 days (P=.0001). The degree of inflammation induced by the drug-eluting stents was higher than that induced by the bare-metal stents at both 3 days (11.8±3.5% vs. 4.5±2%; P=.001) and 7 days (26.3±4.4% vs. 1.2±1.5%; P=.0001). In addition, the time sequence was inverted: the inflammatory response increased over time with the drug-eluting stents, while the opposite occurred with the bare-metal stents.
authors.affiliation: Grupo Cardiovascular de la Fundación Investigación Sanitaria en León e Instituto Universitario de Biomedicina IBIOMED, Hospital Universitario de León y Universidad de León, León, España. aperez@secardiologia.es
authors.forename: Armando
authors.initials: A
authors.lastname: Pérez de Prado
authors.forename: Claudia
authors.initials: C
authors.lastname: Pérez-Martínez
authors.forename: Carlos
authors.initials: C
authors.lastname: Cuellas-Ramón
authors.forename: José M
authors.initials: JM
authors.lastname: Gonzalo-Orden
authors.forename: Marta
authors.initials: M
authors.lastname: Regueiro-Purriños
authors.forename: Beatriz
authors.initials: B
authors.lastname: Martínez-Fernández
authors.forename: Alejandro
authors.initials: A
authors.lastname: Diego-Nieto
authors.forename: Felipe
authors.initials: F
authors.lastname: Fernández-Vázquez
mesh_terms: D000818:Animals; D023903:Coronary Restenosis / Q000473:pathology; D003331:Coronary Vessels / Q000473:pathology*; D054855:Drug-Eluting Stents / Q000009:adverse effects*; D004730:Endothelium, Vascular / Q000502:physiology; D007249:Inflammation / Q000209:etiology* / Q000473:pathology*; D008855:Microscopy, Electron, Scanning; D013552:Swine