When Do Microbubbles Become Macrobubbles in Laser PCI?

During laser atherectomy, the use of contrast can lead to the formation of microbubbles, a common but potentially problematic occurrence. This can result in distal embolization and significant hemodynamic compromise. We would like to share a case of a 64-year-old female who had severe calcified in-stent restenosis with stent underexpansion, which was treated with excimer laser coronary atherectomy. The procedure was complicated by the formation of macrobubbles, which caused slow reflow with temporary hypotension and bradycardia. Laser atherectomy can cause macrobubble formation with distal embolization when using angiographic contrast. To minimize the risk of this complication, it may be reasonable to use more diluted contrast in such cases.