Preoperative Doppler Ultrasound Assessment of Internal Mammary Artery Flow in Coronary Artery Bypass Graft Patients: A Single-Center Study

Background: This study aimed to evaluate the right and left internal mammary artery (RIMA and LIMA) flow dynamics in coronary artery bypass grafting (CABG) candidates using the Doppler ultrasound and explore their associations with clinical and echocardiographic factors. Methods: This prospective observational study enrolled 60 patients scheduled for CABG at Dong Nai General Hospital from January 2023 to December 2024. Doppler ultrasound assessed internal mammary artery (IMA) size, peak systolic velocity (PSV), time-averaged mean velocity (TAMV), flow volume, and atherosclerotic changes. Statistical analyses included paired t-tests, multivariable regression, and correlation analyses. Results: The RIMA was slightly larger than the LIMA (2.3 ± 0.3 mm vs 2.2 ± 0.3 mm, P = .042), with no significant differences in PSV, TAMV, or flow volume. Mean flow volumes were 28.0 ± 12.8 mL/min (RIMA) and 26.2 ± 11.7 mL/min (LIMA). Atherosclerosis was rare (1.7% RIMA, 0% LIMA). Smoking (β = 0.32, P = .014) and dyslipidemia (β = 0.28, P = .029) predicted higher RIMA flow, while age predicted lower LIMA flow (β = −0.35, P = .008). Conclusions: Preoperative Doppler assessment indicated minimal statistical differences but no clinical disparities between the RIMA and LIMA. Individualized preoperative assessment and risk factor optimization remain essential to improve conduit selection and surgical outcomes in CABG.