Clinical results of coronary artery bypass grafting with use of the internal thoracic artery under low free flow conditions

Objective: Even when left internal thoracic artery flow is very low, we hav e used the artery for grafting without any further maneuvers. In this study , we investigated the clinical results of coronary bypass surgery using the left internal thoracic artery with low free flow. Methods: A total of 163 patients were divided into 2 groups: group L (n = 43) had free flow of 20 m L/min or less and group H (n = 120) had free flow of more than 20 mL/min. W e performed a comparative study on the basis of coronary angiography and pu lsed Doppler echocardiography, Furthermore, 12 months' postoperative graft angiography was carried out in 11 patients from group L. Results: No patien t had low output syndrome or perioperative myocardial infarction, One month after the operation, 3 cases of graft occlusion and 9 cases of the "string sign" were identified in group H. However, group L had no graft occlusion and only 1 case of the "string sign." The 1-month postoperative Doppler ech ocardiographic study showed no significant differences in the diastolic fra ction of velocity time integrals and the diastolic/systolic peak velocity r atio of the grafts. In the 11 patients undergoing angiography after 1 year, graft patency was excellent. Moreover, the graft diameter was significantl y larger than it was 1 month after the operation, Conclusion: These results suggest that the left internal thoracic artery can be used for coronary ar tery bypass grafting even when the flow is less than 20 mL/min.