[Laser angioplasty and the removal of calcified plaques. An in vitro study].

The ablative potentials of five different lasers on normal and diseased vascular tissue were tested in vitro. Post-mortem aortic specimens of normal wall, lipomatous and calcified plaques were exposed to both continuous wave lasers (argon, neodymium-YAG 1064 nm) coupled to hot-tipped or sapphire tipped fibres and pulsed lasers (Excimer 193 nm, CO2, erbium-YAG). Histomorphological changes and penetration were evaluated microscopically. Pulsed lasers of all wavelengths used were able to ablate vascular tissue of all stages including heavily calcified plaques. Thermal lasers were able to penetrate the normal wall and lipomatous plaques, but did not reach any evident reaction on calcified plaques. Thermal lasers may have only limited potentials in angioplasty, since ablation of calcified plaques is not possible.