Scoring system for predicting saphenous vein graft patency in coronary artery bypass grafting

The initial and long-term benefits of coronary artery bypass grafting depend upon maintaining the coronary blood flow supplied by the graft. In order to devise a scoring system for predicting graft patency, we evaluated presumptive correlations between saphenous vein graft patency and the characteristics of saphenous veins that were used as conduits in coronary revascularization.We prospectively evaluated 1,000 saphenous vein segments that were implanted in 403 consecutive patients who underwent on-pump coronary artery bypass grafting at our hospital from January 2006 through February 2009. Branches, varicosity, diameter, and wall thickness were evaluated, and a scoring system was created in order to obtain a value for each characteristic. The patients were postoperatively monitored for 1 year, and graft patency was then evaluated with the use of 64-slice multidetector computed tomography.Lesions were found in 12.3% of the grafts. All of the evaluated characteristics of the grafts had a significant correlation with saphenous vein graft flow (P <0.0001). Using the venous characteristics in our statistical analysis, we devised a formula to obtain a score (range, 4-12) to predict the patency of each graft. A cutoff score of 7 yielded 87.8% sensitivity and 82.8% specificity.Our scoring system has good prognostic value. We believe that it can assist surgeons in choosing the most appropriate conduit and target vessel for coronary artery bypass grafting, especially in high-risk patients who are particularly dependent on blood flow through saphenous vein grafts.