An in vitro evaluation of the effect of laser irradiation on the thrombogenicity of thrombus.

The effect of laser irradiation on the thrombogenicity of thrombus was evaluated by treating thrombi, formed in-vitro from canine blood, with two different doses of cw Nd:YAG laser energy at 1064 nm. The thrombi were then incubated with whole blood, and the plasma levels of fibrinogen and thrombin-antithrombin III-complexes were measured. A statistically significant decrease (p < 0.05) in the thrombogenicity was indicated by a reduction in both fibrinogen consumption and levels of thrombin-antithrombin III-complexes in the high dose group (600 joules, 100 degrees C peak temperature) in comparison to the low dose group (300 joules, 70 degrees C peak temperature) and the untreated thrombi. These findings suggest that laser irradiation of thrombus at an appropriate dose may substantially reduce its thrombogenicity and ability to modulate hemostasis.