Risk factors for deep sternal wound infection are diabetes mellitus,25,27,28 obesity (body mass index 30 kg/ ),947,949,950,953,954 chronic obstructive pulmonary disease,950 prolonged CPB time, reoperation, prolonged intubation time, and surgical reexploration.945,947,955 Potentially modifiable risk factors are smoking cessation, optimized nutritional status, adequate preoperative glycemic status (with hemoglo- bin A1c 6.9%), and weight loss. The use of bilateral IMAs has been a subject of investigation as a risk factor for deep sternal wound infection. Each IMA provides sternal branches, which provide 90% of the blood supply to each hemi- sternum. As a result, IMA harvesting can compromise sternal wound healing. Although no RCTs assessing the risk of deep sternal wound infection after bilateral IMA grafting have been reported, the use of bilateral IMAs in patients with diabetes and those with other risk factors for surgical site infection increases the incidence of deep sternal wound infection.956,957 Skeletonization of the IMA may be associated with a beneficial reduction in the incidence of sternal wound complications, more evident in patients with diabetes Transfusion of homologous blood is a risk factor for adverse outcomes after cardiac surgery. Blood transfusions after CABG are correlated in a dose-related fashion to an increased risk of transfusion-related infection, postoperative infection, postoperative morbidity, and early and late death.959 962 In addition, they have been associated with a higher incidence of sternal wound infections.949,963,964 In a retrospective analysis of 15 592 cardiovascular patients, the risk of septicemia/bacteremia and Superficial and deep sternal wound infections increased incrementally with each unit of blood transfused.961 The leukocytes that are present in packed red blood cells induce the immunomodu- latory effects associated with blood transfusions. 