THERMAL CORONARY ANGIOGRAPHY FOR INTRAOPERATIVE PATENCY CONTROL OF ARTERIAL AND SAPHENOUS-VEIN CORONARY-ARTERY BYPASS GRAFTS - RESULTS IN 370 PATIENTS

Background and aim of the study: Early graft failure is often associat ed with technical failures and is therefore potentially avoidable. We used thermal coronary angiography (TCA) for intraoperative graft paten cy control in 370 patients undergoing routine coronary artery bypass g raft surgery to determine whether consequent intraoperative bypass gra ft control may result in improved patency rates. Methods: The temperat ure differences generated in between the myocardium and the grafts by injecting cold cardioplegic solution into the proximal end of a vein g raft or by warmer blood running through an internal thoracic artery (I TA) graft were detected using three different infrared camera systems. The resulting ''heat pictures'' were evaluated for anastomotic patenc y and to outline graft anatomy. Results: A total of 693 vein grafts we re visualized. In 9.4% TCA failed to produce usable images. In the rem aining 628 grafts, TCA revealed intraoperative patency in 98.8%. Out o f 370 ITA grafts, only 14 could not be sufficiently visualized by TCA. Nineteen ITA occlusions (5.3%) were found: 5 intimal flaps; 11 suture imposed strictures; and 3 proximal ITA occlusions. All occluded graft s were subsequently revised or replaced. All sequential ITA as well as 15 right ITA grafts proved to have patent anastomoses. Conclusion: Us ing TCA an early graft dysfunction rate of 1% for vein grafts and 5.3% for ITA grafts could be demonstrated. Most occlusions were due to tec hnical mistakes at the distal anastomosis. TCA outlines grafts and the attached coronaries by temperature differences without the need for a contrast agent. There is no interference with the surgical procedure. It is an ideal, noninvasive method to immediately document the succes s or failure of myocardial revascularization. 147-160)