Impacts of Intraoperative Flow on Graft Patency of Sequential and Individual Saphenous Vein Grafts

OBJECTIVE We sought to delineate the predictor of saphenous vein graft (SVG) failure and to evaluate the impact of sequential grafting of SVG on graft flow as the significant predictor of patency. METHODS Angiograms and clinical records of 439 patients who underwent coronary artery bypass grafting with aortocoronary SVG were reviewed. Of these, 708 distal anastomoses were created by 480 SVGs. Of 349 patients who underwent isolated coronary artery bypass grafting, operation was performed with an off-pump technique in 347 patients (99%). For 90 patients, a combined procedure on cardiopulmonary bypass was performed. A postoperative angiography was performed in 230 SVGs for clinical reasons. Insufficient flow (IF) was defined as a graft flow of 20 mL/min or less, measured by transit-time Doppler flowmetry during operation. RESULTS In 480 SVGs, 44 (9.2%) presented IF, and 24 SVGs presented partial or total occlusion. Six of the nine failed individual SVG had IF, whereas none of the failed sequential SVG was associated with IF. Univariate and multivariate logistic regression analyses demonstrated that IF (P = 0.002; odds ratio, 6.63) and sequential grafting (P = 0.004; odds ratio, 2.51) were significantly correlated with a failure of the SVG. The patency rate of sequential SVG to the most distal target was 78/93 (83.9%), which was significantly lower than 9/139 (93.5%) of the individual SVG (P = 0.02) and 7/113 (93.8%) of the sequential SVG to proximal targets (P = 0.02). CONCLUSIONS When both targets seem to have sufficient demand, avoidance of sequential grafting would be reasonable. Moreover, the important target should be grafted by individual grafting or sequential proximal anastomosis.