Volume 49, Issue 4 Winter 2025 JVU 494-213 | Preoperative Doppler Ultrasound Assessment of Internal Mammary Artery Flow in Coronary Artery Bypass Graft Patients: A Single-Center Study-Preoperative Doppler Ultrasound Assessment of Internal Mammary Artery Flow in Coronary Artery Bypass Graft Patients: A Single-Center Study

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

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This prospective observational study conducted at Dong Nai General Hospital in Vietnam from January 2023 to December 2024 evaluated preoperative flow characteristics of the right and left internal mammary arteries (RIMA and LIMA) in 60 patients scheduled for coronary artery bypass grafting (CABG). Doppler ultrasound was used to measure artery size, peak systolic velocity (PSV), time-averaged mean velocity (TAMV), flow volume, Doppler waveform patterns, and atherosclerotic changes. Clinical and echocardiographic data, including ejection fraction (EF), stroke volume, and diastolic dysfunction, were also analyzed.<br /><br />Key findings showed that the RIMA had a slightly larger mean diameter than the LIMA (2.33 ± 0.34 mm vs. 2.26 ± 0.28 mm, p=0.042), although velocities and flow volumes were comparable between arteries (RIMA flow volume: 28.0 ± 12.8 mL/min; LIMA: 26.2 ± 11.7 mL/min). All IMAs exhibited triphasic waveforms indicating preserved vascular function. Atherosclerotic changes were rare (1.7% in RIMA, 0% in LIMA), consistent with the known resistance of IMA to atherosclerosis.<br /><br />Multivariable regression identified smoking (b=0.32, p=0.014) and dyslipidemia (b=0.28, p=0.029) as predictors of higher RIMA flow, while advancing age predicted lower LIMA flow (b=0.35, p=0.008). Echocardiographic EF correlated weakly positively with RIMA flow (r=0.26, p=0.045) but not significantly with LIMA flow. There was a trend towards reduced LIMA flow in patients with diastolic dysfunction, suggesting possible clinical relevance.<br /><br />The study concludes that although minor size differences between RIMA and LIMA exist, their flow characteristics are largely comparable and clinically equivalent preoperatively. Individualized assessment, especially considering risk factors such as smoking, dyslipidemia, and age, is important for optimizing graft selection and surgical outcomes. Limitations include the single-center design, moderate sample size, and lack of postoperative follow-up data. Further research incorporating postoperative graft patency and flow assessments is needed to validate whether preoperative Doppler parameters predict long-term success of CABG conduits. Overall, this study adds valuable data on bilateral IMA flow dynamics in a Vietnamese cohort, helping refine evidence-based approaches to conduit selection in CABG.

Keywords

right internal mammary artery

left internal mammary artery

coronary artery bypass grafting

Doppler ultrasound

artery flow characteristics

atherosclerosis resistance

smoking impact on artery flow

dyslipidemia effects

echocardiographic ejection fraction

Vietnamese CABG patients