Stent Coating Integrity of Durable and Biodegradable Coated Drug Eluting Stents.
BACKGROUND
Coatings consisting of a polymer and drug are widely used in drug-eluting stents (DES) and are essential in providing programmable drug release kinetics. Among other factors, stent coating technologies can influence blood compatibility, affect acute and sub-acute healing, and potentially trigger a chronic inflammatory response.


OBJECTIVE
The aim of this study was to investigate the short-term (7 and 28 days) and long-term (90 and 180 days) coating integrity of the Xience Prime Everolimus-Eluting Stent (EES), Resolute Zotarolimus-Eluting Stent (ZES), Taxus Paclitaxel-Eluting Stent (PES), and Nobori Biolimus A9-Eluting Stent (BES) in a rabbit ilio-femoral stent model.


RESULTS
Stented arteries (n = 48) were harvested and the tissue surrounding the implanted stents digested away with an enzymatic solution. Results demonstrated that the majority of struts of EES were without any coating defects with a few struts showing minor defects. Similarly, for the ZES, most of the struts were without coating defects at all time points except at 180 days. The majority of PES demonstrated mostly webbing and uneven coating. In the BES group, the majority of strut coating showed polymer cracking.


CONCLUSIONS
Overall, the EES and ZES had fewer coating defects than the PES and BES. Coating defects, however increase over time for the ZES, whereas the percent of coating irregularities remained constant for the EES. These results provide, for the first time, a comparison of the long-term durability of these drug-eluting stent coatings in vivo.
CV Path Institute, Inc., Gaithersburg, Maryland.|University of South Alabama, Mechanical Engineering, Mobile, Alabama.
Saami K
SK
Yazdani
Abbott Vascular, Santa Clara, California.
Alexander
A
Sheehy
Abbott Vascular, Santa Clara, California.
Stephen
S
Pacetti
University of South Alabama, Mechanical Engineering, Mobile, Alabama.
Brandon
B
Rittlemeyer
CV Path Institute, Inc., Gaithersburg, Maryland.
Frank D
FD
Kolodgie
CV Path Institute, Inc., Gaithersburg, Maryland. rvirmani@cvpath.org.
Renu
R
Virmani
D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000627:therapeutic use*; D063566:Biodegradable Plastics / Q000627:therapeutic use*; D020099:Coated Materials, Biocompatible / Q000627:therapeutic use; D003327:Coronary Disease / Q000628:therapy*; D004195:Disease Models, Animal; D054855:Drug-Eluting Stents / Q000009:adverse effects / Q000145:classification; D019544:Equipment Failure Analysis / Q000379:methods; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008422:Materials Testing / Q000379:methods; D008953:Models, Anatomic; D011817:Rabbits; D013997:Time Factors
D000972:Antineoplastic Agents, Phytogenic; D063566:Biodegradable Plastics; D020099:Coated Materials, Biocompatible; D007166:Immunosuppressive Agents