The mechanism of angioplasty--endoscopic and morphometric investigations in an experimental model.

The effect of angioplasty using two different sizes of balloon catheter were examined by angiography and angioscopy before and after dilatation. A significant increase in the outer and inner diameters was seen accompanied by a decrease in the cross sectional area of the stenoses as well as the thickness of the vascular wall. Angioscopy revealed typical longitudinal tears of the plaque edges which are pressed during flow against the vessel wall. Turbidity of saline could be seen after dilatation indicating possible rupture of the atheromatous plaque. These findings are discussed in the light of the mechanisms of angioplasty and the possible reasons for the good early and long-term results.