Availability of the right gastroepiploic artery for coronary artery bypass grafting: preoperative multidetector CT evaluation

Abstract

To evaluate the diagnostic accuracy of multidetector computed tomography (MDCT) angiography for prediction of availability of the right gastroepiploic artery (RGEA) for coronary artery bypass grafting surgery (CABG). This study included 149 patients who underwent both preoperative MDCT angiography and exploratory laparotomy to harvest the RGEA for CABG. The prediction of availability of RGEA using the MDCT finding was evaluated by comparing it to an exploratory laparotomy evaluation of RGEA as a gold standard. The MDCT findings of atherosclerosis and diameter of the RGEA were analyzed. The atherosclerosis of other visceral branches was also analyzed for the detection of affecting factors to the availability for CABG. Atherosclerotic change of vessel was defined as findings including vessel wall calcification, luminal irregularity, aneurysmal change, and apparent atheroma. For statistical analysis, unpaired t-test and receiver operating curve analyses were used to compare the size of the RGEA, and the chi-square test was used to evaluate significant determinant factors of RGEA availability. In exploratory laparotomy, 21 out of 149 RGEAs were classified as inappropriate as a graft for CABG. The reason for inappropriateness was atherosclerosis of RGEA in 15 patients and small diameter in six patients. Sensitivity, specificity, positive predictive value and negative predictive value of MDCT angiography for assessing RGEA atherosclerosis was 60, 99.6, 94.7 and 96.1%, respectively. Atherosclerotic change of the RGEA itself was the only significant determinant factor for predicting the appropriateness of each RGEA. The mean diameter was 1.94mm in 21 inappropriate RGEAs and 2.41mm in 128 appropriate RGEAs. This difference was significant (P=0.001). The least diameter of appropriate RGEA was 1.4mm on MDCT angiography, and the cut-off value determined by ROC analysis was 1.8mm with 82.8% of sensitivity and 61.9% of specificity for inappropriate RGEA, and the area under the curve value was 0.729. MDCT is useful preoperative evaluation tool for RGEA availability. Findings of atherosclerosis of the RGEA and a small diameter on MDCT angiography suggest inappropriateness of the RGEA for CABG surgery.