Abstract 16197: Pedicled Vein Grafts in Coronary Surgery Exhibit Reduced Intimal Hyperplasia at 6 Months

Abstract

Introduction: Less-than-optimal long-term patency of the saphenous vein is one of the main obstacles for the success of CABG. Harvesting saphenous veins including a pedicle of perivascular tissue has been proposed to improve graft patency rates and endothelial function. Hypothesis: We hypothesized that pedicled vein grafts would show less intimal hyperplasia at 6-month angiographic follow-up. Method: Sixty patients scheduled for first time elective on-pump CABG were randomized to conventional or pedicled vein harvesting. Exclusion criteria were insulin dependent diabetes mellitus, recent smoking or renal failure. Pedicled veins were harvested with perivascular tissue and conventional veins were skeletonized. All veins were distended manually to check for leakage and stored in heparinized blood and saline. At 6 months vein grafts were examined with Intravascular Ultrasound (IVUS) and Optical Coherence Tomography (OCT). Imaging analysis was performed by an external blinded Core-lab. Results: Fifty-four patients were available for follow-up. There were no significant differences in occlusion rates between the two groups. IVUS showed no significant difference in intima-media complex thickness (pedicled: n=28, mean 0.229 mm, SEM 0.011; conventional: n = 26, mean 0.235 mm, SEM 0.017). However, using OCT pedicled veins showed significantly less intimal thickness than conventional veins (pedicled: mean 0.270 mm, SEM 0.012; conventional: mean 0.358 mm, SEM 0.021; p<0.001). In conventional veins higher perioperative flow was positively correlated to increased intimal thickness. Such a correlation was not found in pedicled grafts. The difference in response to flow was significant using a general linear model including an interaction term (adjusted R squared = 0.254, p<0.018). Conclusion: Performing CABG using saphenous vein grafts harvested with a pedicle of perivascular tissue provides significantly less vein graft intimal hyperplasia at 6 months.