Reduction of thrombogenicity with argon laser angioplasty. Comparison with balloon angioplasty.

Direct argon or thermal laser angioplasty (LA) was evaluated for thrombogenicity using angioscopy, and compared with balloon angioplasty (BA). In each of 8 dogs, 4 segments (both proximal and distal iliac arteries) were treated by laser-thermal and/or balloon angioplasty. One segment was treated by balloon angioplasty and 3 other segments were treated with either thermal LA with 7 W using a "Hot-Tip" laser probe (2.0 mm), or BA and thermal LA, or a special optical probe which emits a 3 W argon laser beam. Mean percent area stenosis by thrombus was 44 +/- 23 in balloon-dilated, 23 +/- 21 in thermally-treated and balloon-dilated, 3 +/- 3 in thermally-treated, and 1 +/- 4 in directly-lased segments at 30 min. It was 62 +/- 28 in balloon dilated, 31 +/- 29 in thermally-treated and balloon-dilated, 5 +/- 6 in thermally-treated, and 1 +/- 2 in directly-lased segments at 60 min. Balloon-inflated segments had the highest percent area stenosis which was significantly higher than that of either the direct laser or thermally-treated segments (p < 0.0005). Histology showed thermal necrosis in laser-treated sites, and wall tears in BA sites. Thus, LA can provide a less thrombogenic arterial surface than BA.