Endothelialization of nonapposed stent struts located over the origin of a side branch: results with different carbofilm-coated stents.
OBJECTIVE
To evaluate the degree of endothelialization of the nonapposed struts located at the ostia of side branches.


BACKGROUND
Endothelialization of coronary stents has got considerable relevance because of the phenomenon of late thrombosis. Bifurcation location and incomplete stent apposition have been linked to this complication.


METHODS
Domestic pigs (n = 11; weight: 25 +/- 3 kg) were anesthetized and had one stent per coronary artery implanted: one stainless steel (Tecnic), one cobalt-chromium (Chrono), and one tacrolimus-eluting stent (Janus), all of them being Carbofilm-coated (Sorin). One, three, or seven days postprocedure, the pigs were sacrificed, the hearts explanted, and longitudinal sections examined by surface electron microscopy to quantify the percentage of the strut endothelialized over the branches and in the total surface.


RESULTS
Forty-four side branches (25 stents) that had stent struts over their origin were evaluated. Different patterns of endothelialization were observed, from the total absence to the complete endothelialization. There were no significant differences in relation to type of stent or to the artery treated. The predictors of higher percentage of endothelialization were the ratio of metal to branch diameter (P = 0.04) and better endothelialization in the rest of the stent (P = 0.0002), only this parameter maintaining significant correlation (P = 0.03) in multivariate analysis.


CONCLUSIONS
Carbofilm-coated stent struts located over the origin of side branches follow the pattern of endothelialization for the rest of the stent, even in the case of tacrolimus-eluting stent.
Perez De Prado
Armando
A
Interventional Cardiology, Hospital de Leon, Leon, Spain. aperez@secardiologia.es
Perez Martinez
Claudia
C
Cuellas Ramon
Carlos
C
Gonzalo Orden
J Manuel
JM
Altonaga
Jose R
JR
Iglesias
Maria J Garcia
MJ
Regueiro Purriños
Marta
M
Orden
M Asuncion
MA
Marin
Juan F Garcia
JF
Fernandez-Vazquez
Felipe
F
D000704:Analysis of Variance; D000818:Animals; D003324:Coronary Artery Disease / Q000517:prevention & control; D023903:Coronary Restenosis / Q000517:prevention & control*; D003331:Coronary Vessels / Q000473:pathology*; D054855:Drug-Eluting Stents; D004727:Endothelium / Q000473:pathology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D012307:Risk Factors; D013223:Statistics as Topic; D013552:Swine; D016559:Tacrolimus / Q000627:therapeutic use*; D013927:Thrombosis / Q000517:prevention & control*
D007166:Immunosuppressive Agents; D016559:Tacrolimus