Laser tissue interaction in direct myocardial revascularization.

This investigation examines the various laser choices used for transmyocardial laser revascularization (TMLR) with emphasis on the laser-tissue interaction. A series of in vivo (porcine model, n=27) and in vitro experiments were performed to study the effects of CO(2), holmium:YAG, and XeCl excimer lasers on the histological outcome of TMR channels. Computerized histopathological analysis has revealed that the CO(2) and holmium:YAG lasers produce substantial unpredictable thermal damage and differ predominantly in the amount of the mechanical injury or tissue shredding. In comparison, the excimer laser appears to produce the most uniform tissue ablation with the least thermal and shockwave damage. Copyright 2000 Harcourt Publishers Ltd.