Patients
Sixty patients received CABG from the same surgeon from July 2016 to April 2018 (43 males and 17 females, aged 44–76 years, mean age of 61 ± 6 years) were included in this study. All patients suffered from myocardial ischemia because of one or more stenoses of coronary arteries. There were 45 patients with lesions in three or more main branches of the coronary artery, 7 patients with lesions in two branches of the coronary artery, and 8 patients with lesion in only one main branch of the coronary artery. They underwent in situ left IMA bypass to the left anterior descending coronary artery (n = 6 only used left IMA-anterior descending branch as vascular grafts; n = 54 also used saphenous venous grafts). Their general data were collected. Luminal diameters and blood flow of the bilateral IMA of all patients were assessed preoperatively. The ultrasound parameters related to the left IMA were reexamined approximately 1 week after the surgery to evaluate the blood flow and analyze the factors affecting the flow of vascular grafts. The protocol of this study was approved by the ethics committee. All patients signed written informed consent forms before participating in this study.
Exclusion criteria of this study included congenital heart diseases or other structural heart diseases, any significant reduction of left ventricular function (<30%) or recent heart failure, lesions in proximal subclavian artery, vascular graft other than the left IMA to anterior descending branch, and intraoperative rupture in the proximal region of left IMA.