Epicardial ultrasound in off-pump coronary artery bypass grafting: potential aid in intraoperative coronary diagnostics

Background. In off-pump coronary artery bypass surgery (OPCAB), epicardial ultrasound may aid in several intraoperative dilemmas. The aim of this study was to test a new mini-transducer for intraoperative coronary diagnostics. Methods. A 10 MHz mini-transducer (15 × 6 × 9 mm) was applied epicardially in eight open chest and two closed chest porcine OPCAB procedures (using robotics) and on four postmortem human hearts. The transducer fitted in between the suction pods of the cardiac stabilizer and passed an 11-mm port. Results. In the open chest cases the internal mammary arteries (including the side branches) could be visualized totally (n = 12). The left anterior descending coronary artery could be located over its entire course. Vascular anatomy, side branches, and septal perforators (diameter 0.2 mm) could easily be discerned. In the closed chest cases the left anterior descending coronary artery, its side branches, and septal perforators could be visualized in both cases. In the postmortem human hearts the left anterior descending coronary artery could be visualized totally under the thick epicardial fibro-fatty layer and pathologic conditions could be identified. Conclusions. The 10 MHz ultrasound mini-transducer showed promise as a diagnostic tool in both open and closed chest coronary procedures on the beating heart.