ACUTE BIOLOGICAL RESPONSE TO LASER BALLOON ANGIOPLASTY IN THE ATHEROSCLEROTIC RABBIT

Laser balloon angioplasty with Nd:YAG; energy has been proposed as a m ethod to seal intimal dissection and prevent elastic recoil after ball oon angioplasty. To better define the vessel response to laser balloon angioplasty, its effects on luminal diameter, Indium-111 labelled pla telet deposition, and histology were studied in 10 atherosclerotic rab bits. Balloon angioplasty was performed in both iliac arteries and was followed by laser balloon angioplasty in only one iliac artery. The n onlased artery served as a control. Single (15-35 W for 20 sec) or rep etitive laser pulses (12-25 W for 20 sec x 3) were used. Platelet depo sition was quantified 2 hr after the intervention. Lumen diameter (mm) increased following balloon angioplasty from 0.99 +/- 0.47 ( mean +/- SD) to 1.92 +/- 0.43 and 0.89 +/- 0.46 to 1.99 +/- 0.57 in the balloo n and laser-treated arteries, respectively (P < 0.001 for both groups for comparisons to baseline, P = NS for between groups comparison). La ser balloon angioplasty resulted in a further increase in luminal diam eter to 2.42 +/- 0.53 (P < 0.02) when compared to the post balloon ang ioplasty diameter. Platelet deposition (10(6)/cm vessel) was higher fo llowing laser balloon angioplasty (26.9, 10.2-189; median range) than after balloon angioplasty (10.6, 3.4-30), P < 0.001. Histologic eviden ce of laser ''sealing'' was present in only one artery. Thus although laser balloon angioplasty results in an improved lumen diameter, it is accompanied by increased platelet deposition. In the atherosclerotic rabbit model, abolition of vascular recoil rather than ''sealing'' see ms to be the most important advantage of laser balloon angioplasty ove r conventional balloon angioplasty. (C) 1994 Wiley-Liss, Inc.