EXCIMER LASER ANGIOPLASTY IN THE ATHEROSCLEROTIC RABBIT - COMPARISON WITH BALLOON ANGIOPLASTY

The early and late results of excimer laser angioplasty and balloon angioplasty were compared in atherosclerotic rabbit iliac arteries. Immediately after laser angioplasty (n = 13) with a bare 600-mu-m fiber, there was a 33% increase in angiographically measured minimum lumen diameter; after balloon angioplasty (n = 12), there was a 53% increase. Restenosis (defined as loss of at least 50% of the gain achieved by angioplasty) occurred in none of six laser-treated rabbits studied 1 month later, compared with four of six balloon-treated rabbits (p = 0.06). Planimetric measurements of cross sections of the arterial wall 1 month after angioplasty showed less intimal and medial tissue in laser-treated (1.8 +/- 0.2 mm2) than in the balloon-treated rabbits (3.0 +/- 0.4 mm2; p < 0.05). Typical thermal effects were absent on microscopic examination of laser angioplasty sites. It is concluded that in this animal model, excimer laser irradiation results in an immediate increase in lumen diameter comparable with balloon angioplasty, but is associated with less residual atheromatous tissue than balloon angioplasty and a trend toward a lower rate of restenosis.