Fig 1. Wall composition in AAA (left and middle columns) and non-AAA samples (right column).

In the AAA samples, the collagen was more abundant (A), the elastin was partially or mostly destroyed (B), the wall contained more vasa vasorum (D), expressed more hypoxia markers (E) and less contractile phenotype of vascular smooth muscle (C, F). Stained with picrosirius red (A), orcein (B), and immunohistochemistry with anti-smooth muscle actin antibody (C) for visualization of the contractile phenotype of vascular smooth muscle cells, anti-CD31 (D) for visualization of endothelium, anti-HIF 1-alpha (E) for visualization of tissue hypoxia and anti-desmin (F) for visualization of the contractile phenotype of vascular smooth muscle cells; nuclei were stained with Gill’s hematoxylin; scale bar 50 μm.