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Late neointimal tissue growth behind the stent after intravascular γ-radiation

2003; Elsevier BV; Volume: 58; Issue: 1 Linguagem: Inglês

10.1016/s0360-3016(03)00817-4

1879-355X

David Busseuil, Marianne Zeller, Yves Cottin, P. Maingon, I. Barillot, Philippe Allouch, Tibor Ponnelle, Antoine Bril, François Briot, Jean‐Eric Wolf, Luc Rochette,

Angiogenesis and VEGF in Cancer

Purpose To determine the nature of the changes of the vascular wall after intravascular brachytherapy in stented arteries leading to incomplete stent apposition. Methods and materials Stents were implanted in the infrarenal aortas of rabbits, and γ-intravascular brachytherapy (18 Gy) or a sham radiation procedure was immediately implemented. The arteries were harvested at 6 months for histologic analyses. Results 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 [p <0.001] and 1.56 ± 0.13 mm2 vs. 0.72 ± 0.07 mm2 [p <0.001], respectively). The ratio of the intimal area behind the stent related to the total intimal area was greater in the irradiated segments (control vs. irradiated: 9.0% ± 5.9% vs. 55.3% ± 15.5%, p <0.05). Neointimal growth of the irradiated vessels outside the stent was characterized by marked fibrin depositions and an inflammatory response around the stent struts. Conclusion Our study revealed the presence of a neointimal layer specifically located behind the stent, which represented the result of an unhealed fibrin-rich tissue growth process 6 months after intravascular brachytherapy.