Analysis of particle size generated during plaque ablation with a flashlamp pumped pulsed dye laser

Purpose: To examine debris size generated during in vitro plaque ablation by laser energy and estimate the risk of peripheral embolization following laser angioplasty. Methods: A flashlamp pumped pulsed dye laser of 480nm wavelength was used to ablate calcified arteriosclerotic plaque, fibrous fatty plaque, and normal aortic wall on samples of human cadaver aortas. Each tissue sample was immersed in saline solution and treated with the same amounts of laser energy transmitted by a 320 μm-diameter glass fiber in direct tissue contact. The debris generated during plaque ablation was then separated from the supernatant and the particles were counted and analyzed for size. Results: Depending on the underlying type of tissue and the setting of laser energy, a wide range of particles with sizes between 5.3 mm² and 64 μm² was found in samples. The largest particles were found after ablation of calcified atherosclerotic plaque, whereas fibrous, fatty plaque and normal aortic wall showed smaller particles and a lesser amount of debris. Conclusion: Our study demonstrates that a considerable amount of debris is generated during laser angioplasty at 480 nm and that particle size is sufficient to cause potentially symptomatic embolic occlusions of mid- and small-sized peripheral arteries.