Intraoperative bypass graft flow in intra-aortic balloon pump-supported patients: differences in arterial and venous sequential conduits

BACKGROUND: The intra-aortic balloon pump is used worldwide as an anti-ischemic strategy. However, little is known about the modifications of the graft flowmetry during use of intra-aortic balloon pump. METHODS: An observational study aimed at analyzing transit-time flow measurements during 1:1 intra-aortic balloon pump use and during its cessation in 138 consecutive patients using intra-aortic balloon pump before coronary artery bypass grafting (n = 442 graft segments) was reported. RESULTS: In normally functioning grafts, the mean diastolic and mean blood flow improved significantly during 1:1 intra-aortic balloon pump use compared with during intra-aortic balloon pump cessation (P < .001), although mean and diastolic arterial pressures were significantly lower (P = .001). Arterial and sequential saphenous vein grafts showed greater improvements in mean diastolic and mean flow compared with single venous grafts. Surplus graft flow (defined as mean flow during 1:1 intra-aortic balloon pump use/mean flow with intra-aortic balloon pump off) was recorded (surplus graft flow > 1) during 1:1 intra-aortic balloon pump use in all normally functioning grafts, with higher values in single arterial or sequential saphenous vein grafts versus single venous grafts (both P < .001). In the 9 cases of graft failure, the mean diastolic, mean systolic, and mean flow were significantly lower and the pulsatility index greater, compared with normally functioning grafts (all P