Histopathologic evaluation of a novel-design nitinol stent: the Biflex stent.
BACKGROUND
Optimalization and improvement in stent material, stent design and deployment may alleviate the problem of restenosis after stenting. The Biflex stent is a novel-design stent made of nitinol; the vascular response after deployment in rabbit iliac arteries was evaluated.


RESULTS
Normocholesterolemic New Zealand white rabbits (n = 8) were used. Iliac arteries were randomized to receive either a stainless steel control stent or a nitinol stent and rabbits were euthanized at 30 days after implantation. All animals survived and there were no adverse events. Vessels were harvested and prepared for histopathologic analysis and histomorphometry. Stents were well opposed to the vessel wall and thrombi were absent. The lumen area and the area within the internal elastic lamina were significantly larger in the nitinol stent group as opposed to the control group (3.8 +/- 0.1 vs 3.3 +/- 0.1 mm, p = 0.009 and 4.6 +/- 0.1 vs 4.1 +/- 0.2 mm, p = 0.03, respectively). There were no differences in injury score, neointimal area, medial area, area within the external elastic lamina and amount of inflammatory cells. Staining for alpha-smooth muscle cell actin and endothelium did not show any differences between the two groups as assessed semiquantitatively.


CONCLUSIONS
This nitinol stent with a novel design demonstrated acceptable biocompatibility in iliac arteries of normocholesterolemic rabbits with minimal foreign-body reaction and minimal neointimal formation.
Verheye
Stefan
S
Cardiovascular Translational Research Institute, Antwerp, Belgium. stefan.verheye@pandora.be
De Meyer
Guido
G
Salu
Koen
K
Knaapen
Michiel
M
Kockx
Mark
M
D000497:Alloys; D000818:Animals; D001157:Arterial Occlusive Diseases / Q000517:prevention & control / Q000628:therapy*; D001672:Biocompatible Materials; D004867:Equipment Design; D007083:Iliac Artery / Q000473:pathology*; D008297:Male; D011817:Rabbits; D013193:Stainless Steel; D015607:Stents
D000497:Alloys; D001672:Biocompatible Materials; D013193:Stainless Steel; C013616:nitinol