0000000000122985
AUTHOR
François Briot
Late neointimal tissue growth behind the stent after intravascular gamma-radiation.
To determine the nature of the changes of the vascular wall after intravascular brachytherapy in stented arteries leading to incomplete stent apposition.Stents were implanted in the infrarenal aortas of rabbits, and gamma-intravascular brachytherapy (18 Gy) or a sham radiation procedure was immediately implemented. The arteries were harvested at 6 months for histologic analyses.The external elastic lamina area, as well as the vascular wall area behind the stent, were significantly greater in irradiated vs. control arteries (8.94 +/- 0.68 mm2 vs. 6.87 +/- 0.40 mm2 [p0.001] and 1.56 +/- 0.13 mm2 vs. 0.72 +/- 0.07 mm2 [p0.001], respectively). The ratio of the intimal area behind the stent rela…
Intramural neovascularization and haemorrhages are major long‐term effects of intravascularγ‐radiation after stenting
Structural changes that might influence the structural integrity of the vessel in response to intravascular brachytherapy (IVB) and stenting were examined, focus being on the importance of neovascularization in rabbit stented arteries. Stents were implanted in the infrarenal aortas of rabbits, immediately followed by gamma IVB or a sham radiation procedure, and the arteries harvested at 6 months. Labelling for von Willebrand factor showed an increase in adventitial and medial neovascularization in irradiated versus control arteries group (5.04+/-0.89 versus 1.51+/-0.23 mm(-2), respectively; p=0.004). Moreover, intramedial haemorrhages (free hemosiderin deposition) and inflammation (macropha…
Combining Sirolimus-eluting Stents and External Irradiation in Cholesterol-fed Rabbits Increased Incomplete Stent Apposition and Decreased Re-endothelialization
Restenosis after the implantation of a drug-eluting stent or after vascular irradiation therapy shares similar physiopathological mechanisms. No experimental data are currently available on vascular wall behavior after external irradiation on arteries stented with sirolimus-eluting stents (SES). Ten New Zealand white rabbits received a 0.5% cholesterol-enriched chow for 1 month. Bilateral iliac artery stent implantation was then performed with an SES (Cypher; Cordis Corp). The animals were randomized into either an irradiated group (I, 2 Gy external x-ray irradiation, n = 5) or a control group (C, n = 5). The cholesterol-enriched chow was continued for 1 additional month after stent implant…