Angiographic and histologic changes in artery, vein and portal vein after placement of bare or covered Z-stent; an experimental study in dogs.
The aim of this study was to examine stenosis in the aorta, portal vein (PV), and inferior vena cava (IVC) after bare and covered Z-stent placement. Eight beagles underwent bare (n=4) or polytetrafluoroethylene (PTFE) covered (n=4) Z-stent placement in the aorta, PV, and IVC. Angiography was performed 1 and 3 weeks later to evaluate stenosis. The animals were sacrificed after 3 weeks for histopathologic examination. Angiographic findings revealed that stenosis in the bare stent group tended to be smaller than in the covered stent group in 3 vessels and stenosis tended to be smaller in the order of the aorta, PV and IVC in either group. In both groups, stenosis in the PV and IVC was mainly caused by organized thrombus. In addition, in the covered stent group, the space between the cover and native vessel wall (subgraft space) was formed and filled with neointima in every vessel. Preventing thrombus formation in the PV and IVC after bare and covered stent placement and reducing the subgraft space in the aorta after covered stent placement are important for minimizing stenosis.
Sakai
Y
Y
Department of Radiology, Osaka City University Medical School, Osaka, Japan.
Yamada
R
R
Nakamura
K
K
Kaminou
T
T
Lubienski
A
A
D000818:Animals; D001011:Aorta / Q000473:pathology*; D001027:Aortography; D020099:Coated Materials, Biocompatible; D004285:Dogs; D004867:Equipment Design; D010690:Phlebography; D011169:Portal Vein / Q000473:pathology*; D015607:Stents; D014682:Vena Cava, Inferior / Q000473:pathology*
D020099:Coated Materials, Biocompatible