Figure 5-5 shows the OCT diagram of each follow-up time point after Zn Cu stent implantation.
(a) - (f): cross sectional images of vascular segments implanted with Zn Cu stents at the time points of 1, 3, 6, 9, 18 and 24 months. The bright spots distributed around are support rods with black shadows behind; The inner part of the pillar is the neointima; (g) : 3D image of neointima of neovascular membrane implanted with Zn Cu stent at 24 months (top view)
The structure of vascular wall includes intima, media and adventitia. Endothelialization and intimal reconstruction after stent implantation are important indicators of vascular injury repair [31,32]. On OCT images, the annular part with yellow highlight and reflection in the inner layer is the intima of blood vessels; In figures (a) - (d), the obvious bright spot around the intima is the stent rod, and there is a black radial shadow on the back of the stent rod. Figure 5-5 (a) shows that a complete neointima has been formed on the inner wall of the blood vessel one month after the implantation of the zinc copper stent, which means that the endocortization process has been completed within one month after the implantation.
In figures 5-5 (a) - (c), the support rod on the OCT image is clearly visible; From the 9th month (Fig. 5-5 (d)), the support rod becomes blurred; By the end of this study (24 months), the stent rod in the OCT image became almost invisible (Fig. 5-5 (f)). The change process of stent rod from clear to fuzzy on OCT image reflects the gradual degradation of Zn Cu stent in coronary artery.
From 1 month after Zn Cu stent implantation to the end of the study, the neointima on OCT images was smooth, and no signs of thrombosis were observed. It shows that zinc copper stent does not cause serious intimal hyperplasia or thrombosis in animals.
