Intraoperative evaluation of coronary artery bypass graft anastomoses with high-frequency epicardial echocardiography: experimental validation and initial patient studies.

Abstract

There is currently no accepted approach for intraoperative evaluation of the technical adequacy of coronary artery bypass graft anastomoses. High-frequency epicardial echocardiography performed intraoperatively could assess coronary artery bypass graft anastomoses by providing on-line short-axis (cross-sectional) and longitudinal two-dimensional images of the vessels. To validate measurements of anastomoses with high-frequency epicardial echocardiography, luminal diameter determined by high-frequency epicardial echocardiography was compared with that determined histologically after perfusion fixation in 12 dogs studied after coronary artery bypass grafting. Technical errors were deliberately created in some grafts. The results of these animal validation studies showed that maximum luminal diameter of the anastomosis by high-frequency epicardial echocardiography correlated well with histologic measurements (r = .92; high-frequency epicardial echocardiography = 0.8 histology + 0.3). All deliberately created technical errors were detected by an independent observer using high-frequency epicardial echocardiography. After completion of the animal studies, we demonstrated the clinical applicability of this approach in 12 patients. Fifteen coronary artery bypass graft anastomoses were examined intraoperatively with high-frequency epicardial echocardiography. The measured maximum luminal diameter of the anastomosis was greater than the maximum luminal diameter of the native artery, as expected, in all end-to-side anastomoses. However, the maximum luminal diameter of the side-to-side anastomoses was equal to or slightly less than that of the native artery. In this initial patient group, minor technical errors were noted in two of 15 graft anastomoses. In conclusion, high-frequency epicardial echocardiography can accurately measure coronary arterial bypass graft anastomoses and has potential for intraoperative detection of technical errors and inadequacies. Such information may provide a means to detect and correct these technical errors and inadequacies intraoperatively.

High-frequency epicardial ultrasound: review of a multipurpose intraoperative tool for coronary surgery

“…The combined results in 628 patients to assess a total of 912 (segments of) coronary arteries and 418 grafts and distal anastomoses are reported [1-6, 9, 11-18, 20-24, 29-32], as well as experimental validation in animal and ex vivo experiments of 60 coronary arteries and 218 anastomoses [1,2,10,17,[25][26][27][28]. Owing to the heterogeneity of the studies, the review does not include a meta-analysis of the reported findings.…”

“…Anastomosis visualization and assessment in open-chest cases is reported to take approximately 1 min by Hiratzka et al [2] and Suematsu et al [17], and a median of 150s (range 54-335s) by Budde et al [29]. In another early study by Hiratzka et al [4], generally less than 5 min was required per anastomosis.…”

“…Transducer size gradually decreased from rod-shaped transducers as large as 24 9 2.5 cm that were used in the pioneering 1980s studies [2][3][4] to (mini-) transducers as small as 1.5 9 0.9 9 0.6 cm [10,12,13,[15][16][17][20][21][22][23][24][25][26][27][28][29][30] (Fig. 1A).…”

“…In the 1980s, the potential of ECUS to assess anastomosis quality was recognized simultaneously with its value for target coronary artery assessment [1,2]. Highly detailed images of the anastomosis can be obtained (Fig.…”

“…Its use was first reported in the 1980s [1][2][3][4][5][6]. At that time, however, bulky transducers limited their use to the anterior side of the heart, which prevented widespread adoption and application [1][2][3][4][5][6].…”