Explanted grafts stained with hematoxylin and eosin (A & J), CD31 for endothelial cells (B & K), smooth muscle actin for smooth muscle cells (C & L), superimposed images of CD31 and smooth muscle actin(D & M), Hart's for elastin (E & N), Masson's Trichrome for collagen (F & O), Alcian Blue for glycosaminoglycans (G & P), MMP-2 (H & Q), and MMP-9 (I & R).