New Method of Thermal Coronary Angiography for Intraoperative Patency Control in Off-Pump and On-Pump Coronary Artery Bypass Grafting

Background We evaluated the effectiveness of a new thermal coronary angiogram system using intraoperative imaging with an infrared camera for coronary artery bypass grafting. Methods The thermal coronary angiograms of 51 patients who underwent a total of 107 coronary artery bypass grafts were evaluated. Thermal coronary angiograms were obtained after completing distal anastomoses by the injection of cold saline solution into the vein grafts or free arterial grafts or by reperfusion with warmer blood in the internal thoracic artery grafts. Temperature differences of greater than 0.1°C between the injectant and the epimyocardium resulted in high-contrast images. Results Thermal coronary angiograms were obtained from 107 coronary artery bypass grafts; 103 grafts were patent (96.3%), and 2 internal thoracic artery grafts were occluded. After reanastomoses, thermal coronary angiograms were again obtained, and all grafts appeared to be patent. Four grafts did not clearly show hemokinesis because of an intramyocardial segment or circumferential fat surrounding the artery. Conclusions Thermal coronary angiograms cannot show hemokinesis clearly in cases with an intramyocardial arterial segment or in patients in whom the grafts are surrounded by fat. Therefore, thermal coronary angiograms are considered to play a valuable role in confirming the success or failure of myocardium revascularization because this diagnostic modality does not interfere with the surgical procedures, is noninvasive, and can be both quickly and easily performed.