Comparison of the morphological changes of restenosis after the implantation of various types of stents in a swine model.
BACKGROUND
Stent design causes the differences of restenosis rate, but the morphological differences after the various types of stent implantation have not been clarified.


METHODS
Seven types of stents were implanted in pig coronary arteries to clarify how the mechanism of restenosis differs with coil stents and tube stents.


METHODS
The left anterior descending coronary arteries (LADs) of pigs were injured using coronary angioplasty balloons (diameter: 3.0 mm; length: 20 mm; balloon/artery ratio: 1 : 2). Fourteen days after the injury, four types of coil stents (Cordis, Wiktor, GR-I, and GR-II) and three types of tube stents (Palmaz-Schatz, gfx, and Multilink) were implanted, and the LADs were extracted 28 days after the implantation.


RESULTS
The proliferated neointima was eccentric in the coil stents and concentric in the tube stents. Although there was no significant difference in the area of neointima, the area of the lumen was significantly larger in the tube stents than in the coil stents ( < 0.01) because of the larger area of stent. Cells positive for anti-proliferating cell nuclear antigen antibody were mainly observed around the stent struts, and most of these cells were also positive for either anti-macrophage or anti-smooth muscle actin antibodies.


CONCLUSIONS
Compared to the coil stents, the tube stents induce less negative remodelling including stent recoil, resulting in a wider luminal area. In order to prevent restenosis, it is crucial to implant a stent that will cause less negative remodelling.
Yorozuya
Minoru
M
Third Department of Internal Medicine, Showa University School of Medicine, Tokyo.
Suzuki
Hiroshi
H
Iso
Yoshitaka
Y
Shibata
Masayuki
M
Nakatani
Masaki
M
Koba
Shinji
S
Murakami
Mikitaka
M
Katagiri
Takashi
T
Takeyama
Youichi
Y
D000818:Animals; D019917:Blood Vessel Prosthesis Implantation; D002454:Cell Differentiation / Q000502:physiology; D020099:Coated Materials, Biocompatible / Q000627:therapeutic use; D003324:Coronary Artery Disease / Q000150:complications / Q000378:metabolism / Q000601:surgery; D023903:Coronary Restenosis / Q000209:etiology* / Q000378:metabolism; D004195:Disease Models, Animal; D004804:Eosinophils / Q000378:metabolism; D007564:Japan; D008264:Macrophages / Q000378:metabolism; D008297:Male; D008955:Models, Cardiovascular; D015607:Stents; D013552:Swine; D017539:Tunica Intima / Q000378:metabolism / Q000473:pathology / Q000601:surgery
D020099:Coated Materials, Biocompatible