TPT 4.17 Effect of Internal Mammary Artery Harvesting on Sternal Microcirculation in Coronary Artery Bypass Graft patients

Abstract Background The internal mammary artery (IMA) is the conduit of choice for coronary artery bypass grafting; however, its harvesting may compromise sternal blood supply and increase the risk of impaired wound healing. The microvascular consequences of unilateral versus bilateral IMA harvesting are not fully understood. Methods Sternal microcirculation was assessed using laser Doppler flowmetry in patients undergoing coronary artery bypass grafting. Patients were stratified according to unilateral or bilateral IMA harvesting. Serial measurements of sternal perfusion were obtained in the early postoperative period. Microcirculatory flow patterns were compared between groups and analysed in relation to surgical technique. Results Patients undergoing bilateral IMA harvesting demonstrated significantly reduced sternal microcirculatory perfusion compared with those receiving unilateral IMA harvest. The reduction in perfusion was most pronounced in the early postoperative period and was more extensive across the sternal wound area. In contrast, patients undergoing unilateral IMA harvesting showed relative preservation of sternal microcirculation with evidence of progressive recovery. Bilateral IMA harvesting was associated with sustained postoperative hypoperfusion, suggesting a greater disruption of sternal microvascular supply. Conclusion Bilateral internal mammary artery harvesting is associated with a significant reduction in sternal microcirculatory blood flow compared with unilateral harvesting. These findings provide mechanistic insight into the increased risk of sternal wound complications observed with bilateral IMA use. Laser Doppler flowmetry offers a non-invasive method for assessing the microvascular impact of surgical technique and may support individualized conduit selection and perioperative strategies aimed at reducing sternal wound morbidity.