Intraoperative Assessment and Quantification of Coronary Artery Graft Patency Performed on or off Cardiopulmonary Bypass

Abstract

Within the last 10 years, the incorporation of off-pump coronary artery bypass grafting (OPCAB) into many surgical practices has grown. OPCAB requires the surgeon to operate on a beating heart, and it is generally accepted that OPCAB procedures are more technically demanding. Concerns of possible incomplete revascularizations and decreased graft patency have been noted in the literature. The objective of this study was to evaluate and compare on-pump and off-pump intraoperative coronary artery bypass graft (CABG) flow parameters. Intraoperative flow studies conducted with the Butterfly (Medi-Stim Norge AS, Oslo, Norway) flow meter were analyzed retrospectively on 74 patients. Comparisons were completed between patient groups having had their revascularizations performed on or off cardiopulmonary bypass. Our study revealed significant differences in the mean flow rate through saphenous vein grafts (SVG) to the obtuse marginal artery (OM; p = .014), to the diagonal artery (Diag; p = .003), to the right coronary artery (RCA; p = .001), and to the posterior descending artery (PDA; p = .001). Total blood product use showed significantly increased use of both platelets (PLTs) and cryoprecipitate (Cryo) in the on-pump group (p = .027 and .012, respectively). No differences were found for transfusions of red blood cells (RBCs) or fresh frozen plasma (FFP). Additional findings showed a significantly decreased median length of stay (LOS) for the off-pump group. The on-pump patients had a median hospital stay of 7 days (range, 4–24 days), whereas the off-pump patients had a median stay of 6 days (range, 3–22 days; p = .049). Although we were able to show some significance in the mean flow data supporting increased graft flow with the on-pump technique, we were not able to show an overall increase in all recorded flow characteristics to support one method over another.