Assessment of internal thoracic artery patency with transesophageal echocardiography during coronary artery bypass graft surgery.

OBJECTIVE The purpose of this study was to evaluate intraoperative transesophageal echocardiography (TEE) for assessing patency of internal thoracic artery grafts. DESIGN A retrospective study. SETTING A university hospital. PARTICIPANTS Fifty-one consecutive patients who underwent coronary artery bypass graft (CABG) surgery using the left internal thoracic artery (LITA)-to-left coronary artery were examined postoperatively with coronary angiography (CAG). INTERVENTIONS None. MEASUREMENT AND MAIN RESULTS The authors measured blood flow velocity using TEE after anastomosis of a LITA graft. Intraoperative TEE findings and routine CAG results were compared to evaluate the quality of TEE assessment. The LITA was detected in 45 of 51 patients (88%) intraoperatively with TEE. Peak and mean velocities and velocity time integral ratios were determined by dividing each diastolic value by its corresponding systolic value. The peak velocity ratio was 0.51 +/- 0.04 (range, 0.40-0.59) in the presence of stenosis and 1.14 +/- 0.10 (range, 0.58-3.87) in its absence (p = 0.0289), whereas mean velocity ratios were 0.62 +/- 0.05 (range, 0.45-0.72) and 1.27 +/- 0.10 (range, 0.66-4.08) (p = 0.0223), respectively, and velocity time integral ratios were 0.83 +/- 0.09 (range, 0.64-1.05) and 2.69 +/- 0.29 (range, 0.91-8.35) (p = 0.0224), respectively. The critical values for peak and mean velocities and velocity time integral ratios were 0.60, 0.73, and 1.06, respectively, whereas the sensitivity for each was 100% and the specificity was 92%, 94%, and 89%, respectively. CONCLUSIONS The authors concluded that the intraoperative assessment of LITA patency with TEE was a markedly useful and powerful tool for anesthesiologists during CABG surgery.