Potential mechanisms of angioplasty.

There are at least five potential mechanisms for enlarging the arterial lumen using the technique of percutaneous transluminal angioplasty. Each of these mechanisms is reviewed along with evidence from clinical or experimental angioplasty supporting or refuting an actual role for that mechanism in mechanical dilation of diseased vessels. Although plaque compaction is not plausible, each of the other four responses--redistributive modeling of plaque, embolization of plaque components, plastic stretching of the arterial wall, and phagocytic removal of plaque during healing after angioplasty--has been confirmed in at least some circumstances. Since the lesions probably differ in their biomechanical properties, we conclude that it is unlikely that a single mechanism will explain all of the successful dilations.