EFFECT OF MIDINFRARED HOLMIUM-YAG LASER ANGIOPLASTY WITH AND WITHOUT BALLOON ANGIOPLASTY ON ACUTE OUTCOME AND RESTENOSIS IN ATHEROSCLEROTICFEMORAL ARTERIES IN RABBITS

Background and Objective: Pulsed laser may lessen vascular damage and reduce restenosis. This study examined the acute and chronic effects o f midinfrared laser angioplasty with and without balloon angioplasty i n atherosclerotic femoral arteries in rabbits. Study Design/Materials and Methods: Atherosclerosis was induced in arteries by air desiccatio n and cholesterol feeding. Arteries were assigned to one of four group s: (1) laser angioplasty with a Thullium/Holmium/Chromium:YAG infrared laser (Eclipse), (2) balloon angioplasty, (3) laser followed by ballo on angioplasty, and (4) no intervention. Arteries were examined angiog raphically and histologically at 2 hours and 28 days. Results: Interve ntion groups had significant initial gain, but this gain was less with laser alone than after balloon or after laser plus balloon. At 2 hour s, laser alone caused greater arterial damage and thrombosis compared to controls. At 28 days, arteries treated with laser plus balloon had greater narrowing compared with arteries treated with balloon angiopla sty. By multivariate regression analysis, the severity of the pre-inte rvention stenosis (P = 0.001) and intervention with laser plus balloon (P = 0.01) correlated independently with the severity of luminal narr owing at 28 days. Conclusion: Midinfrared Ho:YAG laser angioplasty res ulted in substantial acute damage with increased frequency of thrombus formation in this rabbit model. Arteries treated with laser alone had suboptimal initial gain and more obstruction by plaque at 28 days com pared to nonintervened arteries. The adjunctive use of balloon angiopl asty improved initial gain, but correlated with smaller luminal diamet ers and more severe narrowing by plaque at 28 days. (C) 1995 Wiley-Lis s, Inc.