Detection of internal thoracic artery dissection at coronary anastomosis using intraoperative 15-MHz high-frequency epicardial ultrasound.

A 66-year-old man with a history of diabetes mellitus presented with angina pectoris with 3-vessel disease, and he underwent off-pump coronary artery bypass grafting via median sternotomy. After performing bypass grafting of the left internal thoracic artery to the left anterior descending artery, the appearance of anastomosis configuration appeared to be acceptable. However, transit time flow measurement (TTFM) showed that the mean graft flow was 10 mL/min, which was less than expected despite an acceptable flow curve with a diastolic flow pattern, a pulsatility index (index of resistance) of 2.0, and diastolic filling (proportion of diastole with coronary flow) of 65% (Figure 1). In addition to TTFM, the anastomosis was evaluated by using 15-MHz high-frequency epicardial ultrasound (VeriQ C system; Medistim, Oslo, Norway). It accurately detected an intimal flap of the left internal thoracic artery at the anastomosis site, and the restricted flow pattern in the true lumen was visualized by using Doppler color flow mapping (Figure 2; Movie I in the online-only Data Supplement). The anastomosis was successfully revised, with the use of TTFM to confirm an adequate flow value of 36 mL/ min (Figure 3) and epicardial ultrasound to confirm a good configuration of the anastomosis. There is growing concern regarding the increased risk of errors in anastomosis construction during off-pump coronary artery bypass grafting because the suturing process is technically more demanding than that in surgery on the arrested heart. The European Society of Cardiology/European Association for Cardio-Thoracic Surgery guidelines on myo-cardial revascularization recently recommended intraoperative graft evaluation using TTFM. 1 However, graft flow measurement can only detect severe stenosis (>75%) and provides no information regarding anastomosis configuration; thus, the number of suboptimal anastomoses may be underestimated. In recent years, we introduced an approach using 15-MHz high-frequency epicardial ultrasound to increase diagnostic accuracy relative to that of using TTFM alone. In this case, high-frequency epicardial ultrasound demonstrated its ability to detect an anastomosis error that was not identified by TTFM alone. This approach can be used as a quality-control modality to provide information regarding graft function and anastomosis configuration. Disclosures None.