The results of using microwave (2450 MHz) balloon angioplasty (MBA) in normal and diseased rabbits (animal models) are described. Pathological changes found in the media of normal rabbits ranged from inflamatory cell infiltration to loss of smooth muscle cells with medial thinning. Variable degrees of intimal proliferation were seen. A linear relationship between peak or mean temperature and injury to the media was observed, with an inverse relationship between intimal proliferation and medial injury suggested at one week following the procedure. In the atherosclerotic models, MBA at 85% degrees C resulted in an enhanced lumen diameter compared to conventional balloon angioplasty immediately after the procedure, but appeared to be persistant up to four weeks after BA. >
