Figure 1. Segment of a human right coronary artery with restenosis 5 months after stenting. A, Gross aspect of a cross section shows almost total occlusion caused by excessive neointimal proliferation. B and C, Exuberant neointimal formation around the stent. The sites of stent struts are indicated by arrowheads. D and E, Extensive accumulation of smooth muscle cells around the stent struts (arrowheads), with scattered macrophages and numerous microvessels in the deeper layers of the neointima. AS indicates preexisting atherosclerotic plaque; PTCA, percutaneous transluminal coronary angioplasty. Magnification 18 (B), 62 (C), and 132 (D and E). Reprinted with permission from Komatsu et al. 13