Infrared laser-tissue interaction during transmyocardial laser revascularization
Transmyocardial laser revascularization was found to be a new way how to convey oxygen-rich blood directly from the left ventricular cavity to the myocardium. In our study, a comparison has been made of the interaction of mid-IR solid state laser radiation with a myocardium tissue. For this purpose, the CTH:YAG, Tm:YAG and Er:YAG laser systems were designed, constructed and used for the interaction experiments. Besides those mid-IR lasers, the commercially produced CO2 laser was used for the comparative study. The ablation coefficients were measured to be 0.029 mm/J for CTH:YAG laser radiation; 0.061 mm/J for Tm:YAG; 0.75 mm/J for CO2, and 10.5 mm/J for Er:YAG. From the histological examination follows that only the channels ablated by Er:YAG laser radiation are without any thermal damage of the surrounding tissue and with the minimal mechanical injury. As a conclusion - Er:YAG laser could be considered as a good candidate for the TMR besides CO2 laser.
This paper was published in SPIE Proceedings Vol. 4166
Laser Florence '99: A Window on the Laser Medicine World, Leonardo Longo; Alfons G. Hofstetter; Mihail-Lucian Pascu; Wilhelm R. Waidelich, Editors, pp.48-53