Should use of the internal thoracic artery be avoided under conditions of low free flow? Postoperative hemodynamic assessment using pulsed Doppler echocardiography

There are cases in which it is thought advisable to avoid the use of the le ft internal thoracic artery (LITA) in coronary artery bypass grafting (CABG ) due to its low free flow (FF). However, even though the LITA flow is very low, anastomosis without any further maneuvers intraluminally is recommend ed. The present study investigated the clinical results of CABG, using a LI TA with low FF. The 60 cases of CABG were divided into 2 groups: (i) Group L (n=23), in which LITA FF was less than 20 ml/min; and (ii) Group H (n=37) , in which it was more than 20 ml/min. A comparative study on the basis of coronary angiography and pulsed Doppler echocardiography was performed. In both groups, no LITA graft occlusion was identified, and the 'string sign' was also absent. In the LITA blood waveform, all cases exhibited a biphasic pattern with a higher mid-diastolic and a lower end-systolic component. Th ere were no significant differences in the LITA flow diastolic peak velocit y, velocity time integrals and the diastolic/systolic peak velocity ratios. These results suggest that the LITA can be used for CABG even when the fre e how is less than 20 ml/min.