Off-pump onlay-patch grafting using the left internal mammary artery for a diffusely diseased left anterior descending artery

Abstract

The aims of this study were to evaluate the in-hospital and mid-term outcomes of the off-pump onlay-patch grafting procedure using the left internal mammary artery (LIMA) for a diffusely diseased left anterior descending artery (LAD) and to identify the risk factors for postoperative LIMA graft failure in a single-center retrospective study. A total of 63 patients (52 males, 65.7±9.0 years) undergoing LAD arteriotomy with or without concomitant endarterectomy, followed by reconstruction using LIMA onlay-patch at the time of off-pump coronary artery bypass grafting at our institute from January 2014 to December 2016 were reviewed. The operative mortality, major postoperative morbidity, follow-up all-cause mortality, major adverse cardiac events at follow-up, and postoperative LIMA graft patency were analyzed. The risk factors for postoperative LIMA graft failure on the basis of baseline and surgical characteristics were identified by multivariable logistic regression analysis. Eighteen (28.6%) patients underwent concomitant open LAD endarterectomy. The operative mortality rate was 1.6%. Major postoperative morbidity included perioperative myocardial infarction (3.2%), low cardiac output (1.6%), and reoperation for bleeding (1.6%). During the follow-up period of 24.2±9.5 months, all-cause mortality was 1.7% and the incidence of major adverse cardiac events was 6.8%. No repeat revascularization was recorded. In total, 88.1% of LIMA grafts showed FitzGibbon grade A patency determined by noninvasive coronary computed tomography angiography during follow-up. In addition, concomitant LAD endarterectomy and intraoperative LIMA graft flow were found to be independent risk factors for mid-term LIMA graft failure by multivariable logistic regression analysis (odds ratio=2.681, 95% confidence interval: 1.314-9.856, P=0.007 and odds ratio=0.932, 95% confidence interval: 0.791-0.976, P=0.021, respectively). Revascularization of a diffusely diseased LAD using the off-pump LIMA onlay-patch technique results in encouraging clinical outcomes with favorable angiographic results. Concomitant LAD endarterectomy and intraoperative LIMA graft flow are associated with the risk of postoperative LIMA graft failure.