Abstract 17369: Real-time Identification and Quantification of Competitive Flow at Coronary Artery Bypass Graft Surgery
Background: Competitive flow (native coronary vs. bypass graft, graft vs. graft, regional perfusion bed vs. regional perfusion bed) impacts graft patency to an unknown degree. To avoid competitive flow circumstances (CFC), coronary stenoses < 70% (<50% in LM lesions) are typically not bypassed, but this cutoff is based on subjective interpretation of coronary anatomy and doesn't account for myocardial ischemia and myocardial perfusion characteristics.
Methods: Real-time imaging is evolving to be a quality metric for CABG. Our centers have used the Intraoperative Coronary Fluorescence Vascular Angiography (ICFVA) technique (Novadaq Technologies, Inc.), and analyzed cases locally and in the 460-case Victoria Registry. A new component of ICFVA is SPY-QC, which collects angiographic and measured myocardial perfusion data from the region supplied by the target epicardial coronary artery before and after grafting, and then quantifies the graft-induced change in regional myocardial perfusion to augment the angiographic findings.
Results: 64 grafts were imaged in real-time in 41 patients using the new SPY-QC acquisition/analysis platform; 43 were LIMA to LAD, 21 SV or radial graft to DIAG, CMA or RCA branches. All pts had evidence of ischemia in the target vessel region. SPY-QC data are physiologic, obtained at OPCAB (54%) or at ejecting, low flow cardiopulmonary bypass. All grafts were widely patent on angiographic evaluation; 6/64 grafts (9.3%) had SPY-QC characteristics of competitive flow (FIGURE). In these 6 pts, proximal native coronary stenoses ranged from 70–95% on preop angiogram.
Conclusions: Real-time identification and quantification of competitive flow is feasible and reproducible with the SPY-QC technology. Competitive flow circumstances can exist under conditions where angiographically-significant proximal stenoses are present. This highlights the importance of evaluating both angiographic and perfusion characteristics of grafts at CABG.
- © 2010 by American Heart Association, Inc.