ABSTRACT
Postoperative quantitative evaluation of left internal thoracic artery (LITA) grafts is usually performed by angiography, scintigraphy and Doppler flowire. However it is difficult to observe the characteristics of the intima of the LITA graft. The purpose of this study was to evaluate the characteristics and quantity of plaque of intima of LITA grafts in 6 cases after coronary artery bypass surgery using an intra-vascular ultrasound device (IVUS). There was no stenosis or calcification of LITA grafts on angiography. However we found atherosclerotic plaque in all LITA grafts by IVUS. Characteristics of plaque were eccentric in all cases, and soft, hard and mixed plaque were found. The average minimal lumen diameter of LITA grafts was 2.6±0.2mm. The average lumen area of LITA grafts was 5.4±0.7mm<sup>2</sup>. The rate of plaque area was 37.1±5.9%. The eccentric arteriosclerotic plaques were seen in all cases, contradicting the established theory that LITA do not form arteriosclerosis easily. We suggest that IVUS is an effective follow-up device for evaluating the morphological findings and quantitative evaluation of LITA graft in a timely manner.