Strut tissue coverage and endothelial cell coverage: a comparison between bare metal stent platforms and platinum chromium stents with and without everolimus-eluting coating.
OBJECTIVE
In a rabbit denudation model, assess impact of strut thickness on arterial healing by comparing endothelial cell coverage and strut tissue coverage after implantation of bare metal stents of varying thickness; evaluate the effect of an everolimus-eluting stent.


RESULTS
Strut tissue coverage and endothelialisation were assessed 14 and 21 days after implantation with scanning electron microscopy quantitation methods and immunostaining against the endothelial cell marker PECAM-1 (CD-31). At 14 days, strut tissue coverage was higher with the stainless steel Liberté stent (88%, 97 µm) versus Express (77%, 132 µm). The platinum chromium Element stent with the thinnest strut (81 µm) had the highest level (95%). By 21 days endothelialisation was complete for all. The everolimus-eluting Element stent had a 1-week delay in luminal endothelialisation but was >89% by 21 days; strut endothelial coverage was >79% in 80% (4/5) of animals, with total strut tissue coverage >95%.


CONCLUSIONS
This study demonstrated that strut thickness affects strut tissue coverage post stent implantation and the addition of an everolimus-eluting polymer introduces a short delay in endothelialisation. The results highlight the need to control for aspects of stent design such as strut thickness when comparing across drug-eluting stent platforms.
Boston Scientific Corporation, Natick, MA, USA.
Nicole V
NV
Soucy
Julia M
JM
Feygin
Radhika
R
Tunstall
Melissa A
MA
Casey
Douglas E
DE
Pennington
Barbara A
BA
Huibregtse
James J
JJ
Barry
D015906:Angioplasty, Balloon, Coronary; D000818:Animals; D002857:Chromium; D003331:Coronary Vessels / Q000473:pathology* / Q000648:ultrastructure; D054855:Drug-Eluting Stents; D042783:Endothelial Cells / Q000473:pathology* / Q000502:physiology; D000068338:Everolimus; D005260:Female; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D008670:Metals; D008855:Microscopy, Electron, Scanning; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000032:analysis; D010984:Platinum; D011474:Prosthesis Design; D011817:Rabbits; D020123:Sirolimus / Q000008:administration & dosage / Q000031:analogs & derivatives*; D015607:Stents
D007166:Immunosuppressive Agents; D008670:Metals; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D002857:Chromium; D010984:Platinum; D000068338:Everolimus; D020123:Sirolimus