Abstract 12912: Impact of Graft Configuration of The Right Internal Mammary Artery in Coronary Artery Bypass Grafting: In-situ Versus Y Composite versus Aorto-coronary Bypass
Background: Right internal mammary artery (RIMA) has been used as second graft with various configurations. The aim of this study was to compare the patency of RIMA with using either aorto-coronary bypass (AC) or Y composite grafting proximally anastomosing to left internal mammary artery (LIMA) or in-situ grafting.
Methods: Between January 1996 and June 2013, 324 patients underwent isolated coronary artery bypass grafting (CABG) using RIMA in addition to LIMA-left anterior descending artery (LAD) bypass. Target vessel of RIMA was either diagonal or circumflex branch with significant stenosis. Those patients were divided into 3 groups according to the proximal anastomosis site of RIMA. Group I contained 247 cases with in-situ RIMA grafting. Group A contained 33 cases with AC bypass with proximal anastomosis of RIMA to ascending aorta. Group Y contained 43 cases with Y composite grafting with proximal anastomosis to LIMA. Patients were evaluated by coronary angiography or CT scan postoperatively at discharge and during follow up. Graft patency and risk factors influencing IMA patency were statistically investigated.
Results: RIMA patency at discharge were 97.6% in group I and 97.0% in group A, 93.0% in group Y, respectively (p=0.695). RIMA patency in 5 years were 90.5% in Group I, 100% in group A, 88.4% in group Y, respectively (Logrank P=0.309). LIMA patency at discharge were 99.2% in group I and 97.0% in group A, 97.7% in group Y, respectively (p=0.438). LIMA patency in 5 years were 100% in group A, 96.0% in group I, 76.2% in group Y (Logrank P= 0.009). Survival rate in 5 years were 89.7% in group I, 86.6% in group A, 60.7% in group Y (Logrank P= 0.011).
Multivariate analysis showed Y composite grafting as risk factor in late LIMA occlusion (p=0.024, Hazard ratio (HR) 6.867, 95% Confidence Interval (CI) 1.29-36.5) and late death (p<0.001 HR 2.99, 95% CI 1.70-5.27).
Conclusion: In our study, the patency of RIMA was not significantly different between the groups, but LIMA patency was inferior when used as the inflow of Y composite grafting with RIMA. Y composite grafting may impact on the patency of LIMA and furthermore late survival.
Author Disclosures: J. Sakai: None. T. Komiya: None. H. Tsuneyoshi: None. T. Shimamoto: None.
- © 2015 by American Heart Association, Inc.