Expected Diameter and Velocity Parameters for Internal Mammary Artery Mapping Procedures

Abstract

Background The internal mammary artery (IMA) is the preferred conduit for coronary artery bypass grafting because of its improved long-term patency. Duplex IMA mapping may be requested as a component of preoperative assessment. We reviewed our institutional experience with IMA mapping procedures and determined expected values for IMA size and Doppler parameters. Methods Query was sent to the Cleveland Clinic Non-Invasive Vascular Laboratory database for all bilateral IMA mapping procedures performed from January 1, 2005 to June 30, 2007. Examinations were performed by the use of high-resolution B-mode and Doppler ultrasound. Mean values for IMA dimensions and Doppler parameters were determined along with reference ranges (mean ± 2 standard deviations). Results A total of 949 patients were identified. Mean age was 69.6 years, and 64.7% were men. Patients with significant subclavian stenosis were excluded from the primary analysis. Mean values and reference ranges for right and left IMA size and Doppler parameters are presented in tabular format. Bilateral IMAs were larger in men compared with women ( p < 0.0001). The mean right IMA diameter was larger than left ( p < 0.001). The presence of subclavian artery stenosis was associated with smaller vessel diameter and increased peak systolic velocity. Conclusion We report a range of expected values for preoperative IMA mapping procedures. These data may be used for development of laboratory diagnostic criteria or incorporated into future research on IMA duplex ultrasound for postoperative surveillance.