title: Scanning electron microscopic analysis of polymer damage in drug-eluting stents during multiple stenting.
abstract: Polymer damage of drug-eluting stents (DES) during percutaneous coronary intervention procedure could be associated with stent restenosis. We assessed the damage to the drug-containing polymer of DES during multiple stenting in a phantom model by using scanning-electron microscopy (SEM). Unexpanded sirolimus-eluting stent (SES; n = 15) was delivered through the formerly expanded SES (n = 15) in a bended polytetrafluoroethylene plastic tube. The stent was subcategorized into 4 segments (S), including distal (S1), mid distal (S2), mid proximal (S3) and proximal segments (S4), for qualitative SEM assessment. Polymer damage, such as detachments, missing or tears, was observed not only in the outer surface of the unexpanded stents (100%) but also in the inner surface of the formerly expanded stents (100%). There was a significant difference in the frequency of polymer damage among the 4 segments in the unexpanded stents (S1 vs. S2 vs. S3 vs. S4: 86.7 vs. 80.0 vs. 53.3 vs. 40.0%, p = 0.022) and the formerly expanded stents (S1 vs. S2 vs. S3 vs. S4: 80.0 vs. 73.3 vs. 73.3 vs. 40.0%, p = 0.041). The damage was distributed more frequently in distal part than proximal part of either unexpanded stents (S1 vs. S4, p = 0.0079) and the formerly expanded stents (S1 vs. S4, p = 0.0079). Delivery of DES through a formerly expanded DES could cause damage to drug-containing polymer of the stents.
authors.affiliation: Department of Cardiovascular Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8510, Japan.
authors.forename: Aiko
authors.initials: A
authors.lastname: Shimokado
authors.forename: Takashi
authors.initials: T
authors.lastname: Kubo
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Utsunomiya
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yamasaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Tanimoto
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ino
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.forename: Ikuko
authors.initials: I
authors.lastname: Teraguchi
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ozaki
authors.forename: Yasutsugu
authors.initials: Y
authors.lastname: Shiono
authors.forename: Makoto
authors.initials: M
authors.lastname: Orii
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Shimamura
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamano
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Kumiko
authors.initials: K
authors.lastname: Hirata
authors.forename: Toshio
authors.initials: T
authors.lastname: Imanishi
authors.forename: Takashi
authors.initials: T
authors.lastname: Akasaka
mesh_terms: D002317:Cardiovascular Agents / Q000008:administration & dosage; D054855:Drug-Eluting Stents; D019544:Equipment Failure Analysis; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008953:Models, Anatomic; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000295:instrumentation*; D011108:Polymers / Q000737:chemistry*; D011138:Polytetrafluoroethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure; D020123:Sirolimus / Q000008:administration & dosage; D013499:Surface Properties
chemical_list: D002317:Cardiovascular Agents; D011108:Polymers; D011138:Polytetrafluoroethylene; D020123:Sirolimus
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