Abstract 16388: Prevention of Graft Failure Associated With Competitive Flow and Insufficient Flow Demand in Off-Pump Coronary Revascularization
Objectives: Both sufficient flow demand and prevention of competitive flow are necessary for long-term patency of arterial graft. We assessed efficacy of minimal luminal diameter(MLD) and location of stenosis(proximal or distal portion of target branch) in prediction of graft failure and conduit selection.
Methods: Angiograms of 512 bypass grafts in 280 patients were examined. They included 215 in-situ internal thoracic artery(ITA) to left anterior descending(LAD), 87 in-situ ITA and 52 aorto-coronary saphenous vein graft(SVG) to left circumflex(LCX), and 107 in-situ gastroepiploic artery(GEA) and 51 aorto-coronary SVG to right coronary artery(RCA). MLD was measured at narrowest lesion of the target. Proximal lesion was defined as stenosis at #1~3,5,6 and11, while distal lesion was defined as stenosis at #4,7,and 12~14.
All bypass grafts were individual, and were created as the only bypass graft for each coronary vascular region. Sequential and composite grafts were excluded. ‘Low flow(LF)’ was defined as less than 20ml/min in intraoperative flow and competitive flow in early postoperative angiography, and ‘not functional(NF)’ was defined as string sign or occlusion. Interval between operation and angiography was 2.5±7.4 months.
Results: Overall patency rate was 486/512(94.9%). Of these, 96/512(18.8%) were assessed as LF and 26/512(5.1%) were NF. LF significantly correlated with NF (p<.0001). For ITA to LAD, cut-off MLD was 1.28mm for proximal lesion (p=.006), and 0.75mm for distal lesion (p=.009) For ITA to LCX, cut-off MLD was 1.25mm for proximal lesion (p=.005), and 0.75mm for distal lesion(p=.002), respectively. There was no significant cut-off MLD for SVG to LCX. For GEA to RCA, cut-off MLD was 1.08mm for proximal lesion(p=.002), while 10(71%) of 14 GEA for the distal lesion presented LF, irrespective of MLD. For SVG to RCA, 1.29mm for proximal lesion (p=.001), while 6(43%) of 14 SVG for distal lesion presented LF, irrespective of MLD.
Conclusions: For the targets with MLD more than cut-off value, in-situ arterial graft should be carefully applied. For RCA distal lesion, flow demand may not be sufficient in most cases. Combination of MLD and location of stenosis would be reliable in predicting graft functionality and conduit choice.
- © 2013 by American Heart Association, Inc.