RESUMEN
PURPOSE: In a vascular model the mechanisms of a pulsed dye laser working in a liquid and a gaseous environment was tested and documented by means of a high-speed camera. METHODS: The pulse application (630 nm wavelength) on a target of calcified arterial plaque material was detected at intervals of 20 microseconds up to 800 microseconds total time. RESULTS: In water the laser beam created a cavitation bubble which expanded from 0 to 450 microseconds from a radius 0 to 3 mm and collapsed afterwards. The average expansion velocity of the bubble was 80 m/s in the first 20 microseconds and the resulting velocity of the tube model wall was 10 m/s. Compared with gaseous atmosphere there was no bubble and consecutively no wall stress. CONCLUSION: It is obvious that laser angioplasty causes wall stress and destruction of different vascular layers. This might be the initial stimulation for restenosis. In gaseous atmosphere laser angioplasty should be more protective.