Cardiovascular Intervention and Therapeutics

, Volume 33, Issue 1, pp 55–61 | Cite as

Comparison of the endothelial coverage in everolimus and zotarolimus-eluting stents in normal, atherosclerotic, and bifurcation rabbit iliac arteries

  • Sho Torii
  • Gaku Nakazawa
  • Takeshi Ijichi
  • Ayako Yoshikawa
  • Yohei Ohno
  • Yuji Ikari
Original Article


The aim of this study is to evaluate differences in stent endothelial coverage among the second generation of drug-eluting stents. Incomplete stent coverage is one of the major causes of late stent thrombosis. Rabbits fed a normal diet received an everolimus (Xience Prime; EES) and a zotarolimus-eluting stent (Resolute Integrity; R-ZES) in each iliac artery, followed by sacrifice at 14 and 28 days after stent implantation. In addition, a group of atherosclerotic rabbits similarly received EES and R-ZES, and were sacrificed at 28 days. The extent of stent endothelial coverage was assessed by scanning electron microscopy. To evaluate endothelial coverage after bifurcation stenting, rabbits received EES and R-ZES placed with culotte stenting at the iliac bifurcation, followed by sacrifice at 14 and 28 days. In rabbits fed a normal diet, the percent uncovered strut area 14 days after stent implantation was significantly higher in R-ZES than in EES (10.1% (IQR 9.8–15.5) vs. 3.0% (IQR 1.5–9.7), p = 0.03), whereas it was not significantly different at 28-days (3.9% (IQR 0.8–10.3) vs. 1.0% (IQR 0.0–2.8), p = 0.2). In rabbits with induced atheroma, R-ZES also showed less endothelial coverage 28 days after stent implantation (5.3% (IQR 2.2–9.9) vs. 1.1% (IQR 0–6.2), p = 0.03). In the culotte stenting model, the percent uncovered strut area of the proximal overlapped segment was significantly higher in R-ZES at 14 days (15.8% (IQR 14.3–17.7) vs. 8.8% (IQR 8.3–9.8), p = 0.03) and 28 days (9.9% (IQR 4.1–13.9) vs. 2.5% (IQR 1.6–6.7), p = 0.04) after stent implantation. The carina area also showed a better coverage in EES compared with R-ZES. EES showed a better stent endothelial coverage compared with R-ZES after stent implantation in the early phase in normals, in arteries with lipid rich plaque, and in bifurcation stented sites.


Endothelial coverage Xience Prime EES Resolute integrity R-ZES Culottes stenting Carina 



The authors thank Masayoshi Tokunaga (the Education and Research Support Center, Department of Cell Biology and Histology, Tokai University), Sachie Tanaka, and Katsuko Naito (the Education and Research Support Center, Department of Animal Care, Tokai University) for their valuable technical assistance.

Compliance with ethical standards

The study protocol was reviewed and approved by the Education and Research Support Center, Department of Animal Care in Tokai University (Kanagawa, Japan). There was no industry involvement in the design, conduct, financial support, or analysis of this study.

Conflict of interest

Gaku Nakazawa is a consultant for Abbott Vascular Japan, Terumo Corporation, Japan Medical Device Engineering, and St. Jude Medical and receives research grants from Abbott Vascular, Terumo Corporation, Boston Scientific, Daiichi Sankyo, and Japan Medical Device Engineering. All other authors have no conflict of interests.


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Copyright information

© Japanese Association of Cardiovascular Intervention and Therapeutics 2016

Authors and Affiliations

  • Sho Torii
    • 1
  • Gaku Nakazawa
    • 1
  • Takeshi Ijichi
    • 1
  • Ayako Yoshikawa
    • 1
  • Yohei Ohno
    • 1
  • Yuji Ikari
    • 1
  1. 1.Department of CardiologyTokai University School of MedicineIseharaJapan

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