Do thermal lasers increase the risk of distal embolism in angioplasties? An experimental study with cw Nd: YAG and excimer lasers.

A thermal (contact cw Nd:YAG) and non-thermal (Xe-Cl excimer) laser were used to irradiate fresh human blood in an experimental setting to investigate the possible thrombogenic properties of lasers and to compare the two laser modalities. Blood was obtained into 10 ml citrate test tubes from healthy volunteers. Laser irradiations were performed with cw Nd: YAG laser (10W, 3 and 6 secs) and with excimer laser (20 mJ, 60 ns pulses, 15 secs). Altogether, 80 samples were collected. A thromboelastographic (TEG) analysis was performed for each sample as well as the controls, which were taken simultaneously. Serum potassium levels indicating haemolysis were also determined. Thermal laser energy seems to have more thrombogenic effect than excimer laser. There appear to be no previous reports available in the literature using TEG to determine thrombogenicity of different lasers.