Light and electron microscopic observations in atherosclerotic rabbits following experimental transluminal...

Light and scanning electron microscopy were used to assess the morphologic changes in atherosclerotic lesions in rabbits following percutaneous transluminal angioplasty. Histologic changes observed by light microscopy, i.e. fracture or separation of the plaque and overdistension of the media, were correlated with different balloon sizes. In atherosclerotic rabbits, progressive changes were observed in the vessel wall with increasing size of the balloon. Scanning electron microscopy showed denudation of the endothelial cells, exposure of the subintimal layer, and adhesion of the platelets. In addition, compression of the atheroma, circumferential endothelial rupture, flattening of the intimal fold, and undulation of the intimal fold were observed. Morphometric analysis of histologic sections of the dilated and non-dilated aortas disclosed significant differences in the thickness to width ratio of the plaque. These findings demonstrated that compression of the atherosclerotic plaque could occur.