Detailed observation of arterial healing after stent implantation in swine arteries by using optical coherence tomography.

Abstract

Background: Histopathological examination is not suitable for sequential in vivo analysis of arterial healing after stenting because it can be performed only after the animals are killed. Optical coherence tomography (OCT) provides higher resolution than intravascular ultrasound (IVUS). The aim of this study was to compare arterial healing images after stenting on the basis of the findings of histopathological examination, IVUS, and OCT.

Methods: We examined 12 vessels; 12 bare-metal stents were implanted in 6 miniature swine. Histopathological examination, IVUS, and OCT imaging were performed at 1 and 4 weeks after stenting. For quantitative analysis of IVUS and OCT images, we examined cross-sectional frames at 1-mm intervals. For neointimal coverage analysis, the neointimal coverage score was classified into 1 of the 4 categories. A fully covered strut was scored as 3, a partially covered strut was scored as 1 or 2, and an uncovered strut was scored as 0.

Results: In IVUS and OCT analyses, the average neointimal thickness increased between 1 and 4 weeks (p < 0.0001). OCT revealed higher scores at 1 and 4 weeks than IVUS did (at week 1, p < 0.0001; at week 4, p < 0.0001). OCT analysis evaluated the neointimal coverage similarly to histopathological examination.

Conclusions: On assessment of arterial healing after stenting, we found that the results of the histological examination were more similar to those of the OCT analysis than to those of the IVUS. An OCT imaging device can be used to precisely and sequentially analyze the arterial healing process after stenting.