Iatrogenic left main coronary artery stenosis following PTCA or valve replacement.

We report three patients who developed iatrogenic severe left main coronary artery stenosis. In two, it was secondary to coronary cannulation during aortic valve replacement and in one it followed distention of the artery during balloon dilatation of a proximal lesion in the left anterior descending artery. In all three, the stenosis was clinically manifest a few months after the intervention. All were successfully treated by aortosaphenous coronary bypass. A common mechanism for the three cases may be mechanical distention of the left main coronary artery resulting in intimal damage with secondary fibrosis and stenosis. The percutaneous transluminal coronary angioplasty-related stenosis is, to our knowledge, the first reported case of this nature, and represents a previously unrecognized complication of this procedure.