Abstract
Objective: We sought to validate and evaluate 2 novel intraoperative ultrasound probes for epicoronary and epiaortic imaging. Background: The noninvasive intraoperative assessment of successful coronary artery bypass grafting remains a challenge. Methods: A total of 19 consecutive patients (4 female, 15 male; mean age 60.5 ± 13.8 years SD, range 34-84) underwent coronary artery bypass grafting. The epivascular probes (GE Ultrasound) were validated in vitro and intraoperatively. Coronary arteries, grafts, and ascending aorta were imaged and quantified. Results: Mean adjusted flow measured by flowmeter was 3.25 L, SE 0.47 (range: 1-5.5 L) and was 3.15 L, SE 0.46 (range: 1-5.0 L) by ultrasound, with r = 0.97, P < .0001. Intraoperatively, 56 native coronary vessels were bypassed using 15 left internal mammary artery grafts, 25 vein grafts, and 16 venous jump grafts. A total of 15 left internal mammary artery grafts (100%), 12 left internal mammary artery anastomoses (80%), 20 vein grafts (15 left anterior descending coronary arteries, left circumflex artery grafts, 5 right coronary artery grafts) (80%), 4 jump grafts (25%), and 15 ascending aortas (78%) were successfully imaged by inexperienced surgeons. Doppler flow measurements were possible in 50 vessels (89%). Mean lumen diameter for graft arteries (veins) was 2 mm (2.87 mm), maximal velocity was 72 cm/s (46 cm/s), and mean velocity was 29 cm/s (21 cm/s) with a mean flow rate of 70 mL/m (55 mL/m). Conclusions: We conclude that: (1) the novel intraoperative probes measure validated flow; (2) intraoperative hemodynamic assessment of graft patency is feasible without a learning curve; and (3) these findings should encourage the routine use of these intraoperative epivascular digital ultrasound probes.