Intraoperative epicardial echocardiography with a miniature high-frequency transducer: imaging techniques and scanning planes

Epicardial Echocardiography in Pediatric and Congenital Heart Surgery

Epicardial echocardiography (e-echo) is a useful approach to intraoperative imaging for the smallest patients and in those with contraindications to transesophageal echocardiography (TEE). The e-echo has additional advantages that include improved visualization of anterior and vascular structures and three-dimensional capabilities. In this review, we describe the advantages and disadvantages of e-echo versus TEE for pediatric and congenital heart surgery with the goal of enhancing the utility and feasibility of the former among congenital heart surgeons. We also review the technique for performance of an e-echo and provide demonstrations of the images obtained for select lesions.

Intraoperative assessment of coronary grafts by novel digital epivascular imaging

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.

Intraoperative detection of pulmonary thromboemboli with epicardial echocardiography

We report a novel intraoperative use of epicardial echocardiography in detecting and guiding the removal of pulmonary arterial thromboemboli. We describe a patient with a right atrial thrombus that could not be visualized with intraoperative transesophageal echocardiography. Because we suspected acute pulmonary embolization, epicardial echocardiography was used to visualize the right and left pulmonary arteries. Pulmonary thromboemboli were identified, and pulmonary thromboembolectomy was successfully performed.