Arterial changes after percutaneous transluminal coronary angioplasty: results at autopsy.

Light and electron microscopic examinations were performed on 20 coronary artery sites from nine patients who had undergone percutaneous transluminal coronary angioplasty. Twelve successfully dilated sites without prior thrombosis showed evidence of a tear in the luminal surface (with or without fracture of an atheroma) even at 140 days after angioplasty. The tear split through a relatively undistensible intima in 9 (75%) of the 12 sites. Two successfully dilated sites with prior thrombosis showed an intraintimal tear with a widely lacerated fibrous cap and thin mural thrombus. After dilation, the occluded prior nonthrombosed site showed marked protrusion of a separated plaque. An occluded prior thrombosed site after dilation revealed intraintimal canal-like hematoma. Four sites that occluded after balloon passage revealed a dissecting hematoma in three and plaque disruption in the other.