Morphometric and histologic assessment of remodeling associated with restenosis after percutaneous transluminal coronary angioplasty.

The role of remodeling in restenosis of coronary arteries on which percutaneous transluminal coronary angioplasty (PTCA) had been performed was investigated. At autopsy, presence (n = 6) or absence of restenosis (n = 5) based on the cross-sectional area of stenosis was determined in 11 coronary lesions. Remodeling was defined as a ratio of the artery area at the PTCA site to that at the reference site of <1.0. According to this definition, remodeling had occurred in all of the lesions in the restenosis group, and in only 1 lesion in the group with no restenosis which had the least residual plaque (p < 0.05). Dense caps of collagen fibers in the adventitia in the vicinity of the disrupted internal elastic laminae were present in all of the remodeling lesions. We suggest that remodeling, which results in adventitial scarring, is one of the major causative factors of restenosis.