Method for Disruption and Re-Canalization of Atherosclerotic Plaques in Coronary Vessels With Photothermal Bubbles Generated Around Gold Nanoparticles

Background and Objectives: Rapid and safe re-canalization of totally occluded coronary vessels, especially those with the calcified plaques, represent a challenge for cardiology. Study Design/Materials and Methods: We have suggested to employ photothermal microbubbles (PTMBs) that are generated around injected to plaque or thrombus gold nanoparticles with a short laser pulse for selective mechanical disruption and removal of the plaque tissue and without thermal and mechanical damage to arterial wall. PTMBs were generated in vitro around 30-250 nm gold spheres and with 1.0 nanoseconds laser pulse at 532 nm in three models: the layer of the living fibroblasts, the epoxy layers, and human arteries with plaques. Results: In all three models, complete removal of the material was observed after 1-10 single laser pulses. The size of cleared zones (20-220 mu m) was Found to he 5001,000 times bigger than the size of the nanoparticles applied. PTMB generation did not increase the temperature of the microenvironment outside PTMB and the debris size was below 2 mu m. Conclusions: New proposed method for non-thermal mechanical and localized removal of plaque tissue with PTMB can provide safe and rapid re-canalization of totally occluded and calcified arteries without collateral damage. Lasers Surg. Med. 41:240-247, 2009. (C) 2009 Wiley-Liss, Inc.