Determinants of stent expansion in curved stenotic lesions: an in vitro experimental study.
OBJECTIVE
This study compared the expansion parameters of four different new-generation balloon-expandable stents in a curved stenotic phantom model.


METHODS
Five stents for each length and type, each with a 3.5-mm diameter (AVE, 12 mm and 18 mm; Penta, 13 mm and 18 mm; BX-Sonic, 13 mm and 18 mm; and Jostent Flex Master, 12 mm and 16 mm), were implanted in curved silicon models 3.25 mm in diameter with 58% concentric elastic stenoses. The forces exerted on the inner curvature were continuously registered. Minimal luminal diameter (MLD) and reference luminal diameter (RLD) of the stents, inflated balloon diameter at both ends of the stents during inflation (BD(ref)), and balloon diameter at the stenotic site during inflation (BD(min)) were determined by magnification radiography.


RESULTS
The Penta and AVE stents presented greater RLD (Penta, 3.78 mm +/- 0.08; AVE, 3.75 mm +/- 0.13; BX-Sonic, 3.47 mm +/- 0.06; Jostent, 3.28 mm +/- 0.06) and MLD values (Penta, 2.94 mm +/- 0.18; AVE, 3.05 mm +/- 0.19; BX-Sonic, 2.68 mm +/- 0.06; Jostent, 2.53 mm +/- 0.09) than the BX-Sonic and Jostent stents. Displacement forces after stent placement were greater for AVE (0.034 N +/- 0.015) and Penta stents (0.023 N +/- 0.017) than for BX-Sonic (0.013 N +/- 0.007) and Jostent stents (0.009 N +/- 0.007; P <.05). BD(min) was correlated in a linear fashion with MLD (r = 0.84; P <.001), as was BD(ref) with RLD (r = 0.92; P <.001), for all stents.


CONCLUSIONS
Inflated balloon diameter was the main determinant of stent expansion. The AVE and Penta stents gained larger MLD values than the BX-Sonic and Jostent stents, but they excessively dilated the nonstenotic region of the model.
Poerner
Tudor C
TC
First Department of Medicine, University Hospital of Mannheim, Germany.
Ludwig
Bettina
B
Duda
Stephan H
SH
Diesing
Peter
P
Kalmár
Gábor
G
Süselbeck
Tim
T
Kaden
Jens J
JJ
Borggrefe
Martin
M
Haase
Karl K
KK
D000704:Analysis of Variance; D001157:Arterial Occlusive Diseases / Q000628:therapy*; D001696:Biomechanical Phenomena; D002404:Catheterization; D066298:In Vitro Techniques; D016014:Linear Models; D008953:Models, Anatomic; D012828:Silicones; D018709:Statistics, Nonparametric; D015607:Stents
D012828:Silicones