A TIME SEQUENCE OF VESSEL WALL CHANGES IN AN EXPERIMENTAL-MODEL OF ANGIOPLASTY

A detailed temporal sequence of vessel wall changes in a rabbit model of balloon angioplasty, to the iliac arteries, at 30 min, 2 h, day 1, day 3, day 7, day 14, 1 month, and 3 months was established using ligh t microscopy, immunostaining for proliferating cell nuclear antigen, a nd electron microscopy. Complete endothelial denudation with extensive platelet and fibrin deposition was evident early. Intimal thickening, characterized by myointimal hyperplasia, was observed at day 7 and re ached a maximum at 1 month. Re-endothelization was complete by day 14. Cellular proliferation, seen early at day 1, reached a maximum at day 7 for the media and day 14 for the intima before returning to baselin e levels by 1 month. This simple model of angioplasty with its reprodu cible myointimal hyperplasia should prove useful for assessing any pot ential agents for inhibiting this process.