Fig. 4.

Representative long-term histological images of nitrided iron scaffold in porcine coronary artery (HE staining). HE staining images at: (A) (D) 2.5 years, the scaffold was partially corroded, and there were significant granulomatous reactions with hemosiderin laden macrophages and neovascularization; (B) (E) 4.5 years, most iron struts were completely corroded, and the iron corrosion products were engulfed by macrophages and began to migrate to the vascular adventitia; (C) (F) 7 years, the iron struts were almost completely bioabsorbed in situ, and only a small quantity of corrosion products was observed in the vascular adventitia, and the space of corroded scaffold was repaired by normal tissue.