Evaluation of coronary artery bypass graft patency using three-dimensional re construction and flow study of electron beam tomography

Objective To establish and evaluate two protocols for the noninvasive visualization and as sessment of coronary artery bypass graft (CABG) patency on electron beam tomogra phy (EBT).Methods Two hundred and fourteen consecutive patients who underwent coronary artery bypa ss graft surgery were scanned using both EBT angiography with 3-dimensional rec onstruction and EBT flow study with time-density-curve analysis. Results There were 589 CABGs evaluated in this study (10 grafts were excluded because of artifacts). Among them, 133 (98.5%) of 135 arterial grafts were patent, and 3 45 (77.7%) of 444 saphenous-vein grafts were patent. Within 5 years or betwee n 5 and 10 years after operation, arterial graft patency exceeded venous graft p atency (P<0.001). Three-dimensional EBT angiography achieved higher sensi tivity, specificity and accuracy (97.7%, 94.1% and 96.7%, respectively) than did EBT flow study (88.4%, 82.4% and 85.2%, respectively) for evaluating occl usion or patency of CABG. The intra-graft flow of patent arterial and venous g rafts were 4.9±2.2 ml·min(-1)·g(-1) and 6.9±2.8 ml·min (-1)·g(-1), respectively (P<0.001). Conclusion The combination of EBT three-dimensional reconstruction and flow study can be m ore effective in the assessment of CABG anatomy and quantification of patent CAB G blood flow.