Comparison of in vivo longitudinal strength and conformability following stent implantation in rabbit iliac artery.
OBJECTIVE
The aim of this study was to determine the in vivo longitudinal strength and conformability of various stent platforms following stent implantation in rabbit iliac arteries.


BACKGROUND
Recently, longitudinal coronary stent deformation has been highlighted and bench tests have demonstrated differences in longitudinal strength among various stent platforms. However, this has not been investigated in an in vivo setting. This is of interest because there may be a trade-off between longitudinal strength and conformability.


METHODS
We evaluated 4 types of commercially available stents: Multi-Link 8 (Abbott Vascular); Omega (Boston Scientific); Integrity (Medtronic); and Nobori (Terumo Corporation). To investigate the longitudinal strength, constant axial force was applied to the stent edge by a guiding catheter after deployment in a rabbit iliac artery. The amount of longitudinal stent deformation was calculated by measuring stent length. In order to evaluate conformability, stents were deployed crossing over the iliac bifurcation and the bifurcation angles were measured before and after stent implantation. If the change in the angle was small, the stent was considered to be more conformable.


RESULTS
The Omega stent demonstrated significantly greater longitudinal compression compared with other stents (Omega, 17.4 ± 9.3%; Multi-Link 8, 2.8 ± 2.3%; Integrity, 2.8 ± 1.4%; Nobori, 3.8 ± 3.2%; P=.01), but Omega showed better conformability, as evidenced by the smallest percent change in the bifurcation angle (Omega, 12.7 ± 0.8%; Multi-Link 8, 25.7 ± 2.4%; Integrity, 28.3 ± 1.1%; Nobori, 28.1 ± 6.8%; P=.03).


CONCLUSIONS
In this rabbit model, the Omega stent, which has the platform of the Element stent, showed less longitudinal strength but greater conformability compared with the other stent platforms.
Tokai University School of Medicine, Cardiology, 143 Shimokasuya, Isehara, Kanagawa 2591193, Japan. gnakazawa@tokai-u.jp.
Sho
S
Torii
Gaku
G
Nakazawa
Takeshi
T
Ijichi
Ayako
A
Yoshikawa
Yohei
Y
Ohno
Naoki
N
Masuda
Norihiko
N
Shinozaki
Nobuhiko
N
Ogata
Yuji
Y
Ikari
D000818:Animals; D002406:Catheterization, Peripheral / Q000295:instrumentation*; D054855:Drug-Eluting Stents / Q000145:classification / Q000592:standards*; D004867:Equipment Design / Q000145:classification / Q000592:standards*; D007083:Iliac Artery; D008422:Materials Testing / Q000379:methods; D023421:Models, Animal; D011817:Rabbits; D013718:Tensile Strength