Vasomotor function and re-endothelialisation after implantation of biodegradable abluminal polymer coated paclitaxel-eluting stents in rabbit iliac arteries: a time-course study.
OBJECTIVE
To evaluate the time-course of vasomotor function and re-endothelialisation after implantation of a novel platinum-chromium (PtCr) abluminal biodegradable polymer-coated paclitaxel-eluting stent (PES, Labcoat Element) in rabbit iliac arteries.


RESULTS
Either PES (n=18) or an identical platform of bare metal stents (BMS, Element, n=18) were implanted in rabbit iliac arteries (six animals per time-point). At 14, 30, and 90 days, acetylcholine- and nitroglycerine-induced vasomotor reactivity at 5-10 mm distal to the stent was measured. Subsequently, the animals were terminated. The stented artery was bisected longitudinally for either SEM or en face CD31 immunochemistry examination. All arteries were patent with normal angiographic flow. Decreased endothelial-dependent vasomotion was found at both 14 and 30 days for PES compared to BMS (p<0.01, respectively); however, these differences resolved by 90 days. Endothelial-independent vasorelaxation was similar at all three time-points. Both SEM and en face staining demonstrated equivalent endothelial coverage on the surface of the stented segments above and between struts at all time-points.


CONCLUSIONS
This novel bioabsorbable polymer abluminal-coated PES demonstrated vasomotor function comparable to BMS within three months post-deployment in the rabbit iliac model. Despite indistinguishable endothelial cell coverage on the stent surface between groups, earlier differences in vasomotion were detected: this finding suggests that the timing of restoration vasomotor function lags morphologic endothelial recovery.
Saint Joseph's Translational Research Institute/Saint Joseph's Hospital of Atlanta, GA, USA.
Takamitsu
T
Nakamura
Dawn
D
Winsor-Hines
Xinhua
X
Yin
Natalia
N
Sushkova
Jack P
JP
Chen
Spencer B
SB
King
Nicolas
N
Chronos
Michael
M
Eppihimer
Barbara
B
Huibregtse
Keith D
KD
Dawkins
Dongming
D
Hou
D020341:Absorbable Implants; D000418:Albumins; D000818:Animals; D049109:Cell Proliferation; D054855:Drug-Eluting Stents; D004730:Endothelium, Vascular / Q000473:pathology*; D007083:Iliac Artery / Q000473:pathology* / Q000503:physiopathology* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D018384:Oxidative Stress / Q000502:physiology; D017239:Paclitaxel; D011108:Polymers; D011817:Rabbits; D015607:Stents; D013997:Time Factors; D014657:Vasculitis / Q000473:pathology / Q000503:physiopathology; D014666:Vasomotor System / Q000502:physiology*
D000418:Albumins; D011108:Polymers; D017239:Paclitaxel