Beurteilung der intraoperativen Offenheit von Koronarbypässen sowie Bestimmung von Stenosen unterschiedlichen Schweregrades mittels Fluoreszenzangiographie

Intraoperative graft patency verification is of major clinical importance for quality control after coronary artery bypass grafting (CABG). The purpose of this study was the assessment of graft patency and stenosis of variable severity by fluorescence angiography (FA) using indocyanine green (ICG). In this study 32 domestic pigs (40 – 70 kg) were examined by FA technique. ICG induced fluorescence imaging was performed on the native coronary vessels (n = 6) and stenoses (n = 8) of the left anterior descending coronary artery (LAD). In 18 pigs CABG was performed using left internal mammary artery or vein graft to LAD on the beating heart. Artificial obstructions of LAD or bypass anastomoses at various grade were created. FA was compared to coronary angiography (CA) and transit time flowmeter (TTFM) after each intervention. In all cases coronary flow and flow reduction could be determined by FA and correlated highly to TTFM values. Additionally, FA could measure myocardial perfusion and functional impairment of coronary bypass during graded stenosis, determined by the reduction of myocardial fluorescence. FA and CA identified the different stenoses as well as total occlusion of the LAD and the bypass anastomosis in all cases. FA can determine the degree of blood flow reduction in ischemic vs. normal myocardium during graded coronary and bypass stenoses. The method is highly sensitive and reproducible and an excellent technique for intraoperative quality control in CABG.