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

Objective To establish and evaluate two protocols for the noninvasive visua lization and assessment of coronary artery bypass graft (CABG) patency on e lectron beam tomography (EBT). Methods Two hundred and fourteen consecutive patients who underwent coronar y artery bypass graft surgery were scanned using both EBT angiography with 3-dimensional reconstruction and EBT flow study with time-density-curve ana lysis. Results There were 589 CABGs evaluated in this study (10 grafts were exclud ed because of artifacts). Among them, 133 (98.5%) of 135 arterial grafts we re patent, and 345 (77.7%) of 444 saphenous-vein grafts were patent. Within 5 years or between 5 and 10 years after operation, arterial graft patency exceeded venous graft patency (P < 0.001). Three-dimensional EBT angiograph y achieved higher sensitivity, specificity and accuracy (97.7%, 94.1% and 9 6.7%, respectively) than did EBT flow study (88.4%, 82.4% and 85.2%, respec tively) for evaluating occlusion or patency of CABG. The intra-graft flow o f patent arterial and venous grafts were 4.9 <plus/minus> 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 more effective in the assessment of CABG anatomy and quantifi cation of patent CABG blood flow.