Transmyocardial laser revascularization with the Holmium:YAG laser does not improve myocardial perfusion in the acutely ischemic heart: an experimental study measuring myocardial perfusion by a thermal imaging camera

BACKGROUND: Transmyocardial laser revascularization (TMLR) is a new surgical therapy for patients with end-stage coronary artery disease refractory to conventional therapy. TMLR should act by improvement of perfusion of the lasered myocardium. Blood should be delivered from the cavity of the heart to the surface of the myocardium. The aim of this study was to measure perfusion of normal, ischemic, and ischemic myocardium after TMLR. METHOD: We used a new method of perfusion measurement by an infrared thermal imaging system in an open-chested adult sheep model with temporary and permanent occlusion of the dominant diagonal branch. RESULTS: A significant fall from normal perfusion of the myocardium to reduced after inducing ischemia (p<0.01) and a significant rise again after reperfusion (p<0.001) could be shown. Perfusion measurements after TMLR did not significantly differ from perfusion measurements after inducing ischemia (p=0.2). CONCLUSION: In the presented sheep model, laser revascularization could not improve myocardial perfusion after acute ischemia as seen by the infrared thermal imaging system.