Late neointimal volume reduction is observed following biodegradable polymer-based drug eluting stent in porcine model

Figures

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  Fig. 1. Study Flow Chart. All animals underwent OFDI at either 1 or 3 months and at 9 months. After euthanasia at 9 months, stents were histologically investigated to analyze the vascular response and its maturity. One animal died before the euthanasia in each of the 2 BMS groups.

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  Fig. 2. Representative Image of the Peri-strut Low-intensity Area. A representative image of the peri-strut low-intensity area (red arrow). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

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  Fig. 3. Representative Histologic Sections Stained with a Combined Verhoeff and Masson Trichrome for Calculation of the Maturity Score. Sections show a high-power (20×) magnification following combined Verhoeff and Masson trichrome staining. Immature tissue (score = 1) was defined as fiber-rich extracellular matrix with few smooth muscle cells. Inflammatory cells, macrophages, and fibrin were mainly observed surrounding stent struts (A). Mature tissue (score = 2) showed abundant smooth muscle cells in neointimal tissue with few inflammatory cells (B).

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  Fig. 4. Regression in the Neointimal Volume from 3 to 9 Months. Regression in the neointimal volume was analyzed by OFDI at 3 and 9 months.

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  Fig. 5. Percent Distribution of the Vascular Response in Each Stent. Histological distribution of the vascular response at 9 months. The vascular response was assessed using injury, inflammatory, and maturity scores. *p < 0.05, **p < 0.01.