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 light microscopy, immunostaining for proliferating cell nuclear antigen, and 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 reached 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 baseline levels by 1 month. This simple model of angioplasty with its reproducible myointimal hyperplasia should prove useful for assessing any potential agents for inhibiting this process.