Figure 5-9(a) shows the 3D Micro-CT reconstruction image of the Zn-Cu stent before implantation. Figure 5-9(b) shows that the zinc-copper stent degrades fairly uniformly within the first 3 months after implantation, and there is no accumulation of local corrosion products; in Figure 5-9
A dense continuous corrosion layer can be seen in (b)-(d), which means that 9 months after implantation, the main type of corrosion is still uniform corrosion; Figure 5-9(c) shows 6 stents implanted In the reconstructed image after one month, it can be seen that the zinc-copper stent still maintains mechanical integrity 6 months after implantation, but at this point in time, some local corrosion locations in the pillar can be found. Nine months after implantation (Figure 5-9(d)), the bending of the stent rod began to break. By the 12th month, the stent structure had been severely disintegrated (Figure 5-9(e)). At this time, there was almost no complete support unit, indicating that the stent had completely lost its supporting function. However, the collapse of the stent support structure also represents the release of the stent's binding effect on the blood vessel, which is a prerequisite for the positive remodeling of the blood vessel after the implantation of the degradable stent. (A) 3D Micro-CT image of Zn-Cu stent before implantation; (b), (c), (d), (e), (f) and (g) are implanted 3, 6, 9, 12 3D Micro-CT images after 18 and 24 months. Each time point is composed of three images: green represents corrosion products (front view); green represents corrosion products (front view). The white one is the combination of residual zinc and corrosion products (the right view is the middle view and the right view is the top view).
