Vapor Bubble Expansion and Implosion: The Origin of "mile Feuiiles

The aim of our study was to demonstrate, in vivo, bubble expansion in blood and to assess any damage to the arterial wall after 1-10 excimer laser pulses (55mJ/mm2). Time resolved flash photography demonstrated the expansion and implosion of a vapor bubble, which induced a 50%diameter increase of the artery within 75s and a subsequent invagination (150-500 ps). This microsecond dilation and invagination caused extensive wall damage (up to 1.9 mm) far beyond the penetration depth of 308 nm laser light (< 100 pm). The damage, which increased with the number of laser pulses, may be related to the dissections observed after excimer laser coronary angioplasty