title: Comparison of ablation efficacy of excimer, pulsed-dye, and holmium-YAG lasers relevant to shock waves.
abstract: Ablation efficacy of pulsed lasers on human arterial tissue and associated shock waves have been investigated by means of excimer laser at 308 nm, pulsed-dye laser at 480 nm, and holmium-YAG laser at 2.1 microns. A multifiber catheter was used for lasing at 420 mjoules/pulse with holmium-YAG, 18.9 mjoules/pulse with excimer, and 100 mjoules/pulse with pulsed-dye laser. Ablation efficiency (ablated volume/energy) was greatest with pulsed-dye laser in blood and excimer laser in saline solution. There was selectivity for atheroma with pulsed-dye laser (ablation efficiency in atheroma versus normal tissue, 58 versus 27 x 10(-2) mm3/joule in blood; p less than 0.005) and holmium-YAG laser (12.6 versus 5.6 x 10(-2) mm3/joule in blood; p less than 0.001). Ablation efficiency of pulsed-dye laser was enhanced by blood (0.58 in blood versus 0.17 mm3/joules in saline for atheroma; p less than 0.005). Shock waves were correlated with ablation efficiency (r = 0.63 and 0.74 for pulsed-dye laser and holmium-YAG laser, respectively). There was neither selectivity for atheroma nor influence of blood medium with excimer laser. Only holmium-YAG laser could ablate tissue at a distance from the target in the blood medium. Histologic findings showed that all lasers could create smooth-edged craters with minimal coagulation necrosis. In conclusion, laser irradiation with holmium-YAG and pulsed-dye lasers could selectively ablate atheromatous tissue with minimal thermal injury, whereas excimer laser could not. Ablation efficiency was correlated with shock waves. Efficiency of pulsed-dye laser was enhanced by blood.
authors.affiliation: Explorations Fonctionnelles, Henri Mondor Hospital, University of Paris XII, Créteil, France.
authors.forename: T
authors.initials: T
authors.lastname: Tomaru
authors.forename: H J
authors.initials: HJ
authors.lastname: Geschwind
authors.forename: G
authors.initials: G
authors.lastname: Boussignac
authors.forename: F
authors.initials: F
authors.lastname: Lange
authors.forename: S J
authors.initials: SJ
authors.lastname: Tahk
mesh_terms: D016342:Angioplasty, Laser / Q000009:adverse effects / Q000295:instrumentation* / Q000706:statistics & numerical data; D001011:Aorta / Q000473:pathology / Q000601:surgery; D001161:Arteriosclerosis / Q000473:pathology / Q000601:surgery; D001769:Blood; D002406:Catheterization, Peripheral / Q000295:instrumentation; D005069:Evaluation Studies as Topic; D006801:Humans; D066298:In Vitro Techniques; D012965:Sodium Chloride; D014465:Ultrasonics / Q000009:adverse effects*
chemical_list: D012965:Sodium Chloride