title: Coronary artery bypass grafts: increased flow in the early postoperative period.
abstract: The long-term outcome of coronary artery bypass operations is contingent upon the patency of aortocoronary bypass grafts. Flow measurements taken at operation may not truly reflect the capacity of the graft to carry glow because the heart may not have fully recovered from the consequences of ischemic arrest, despite the protective effects of hypothermic cardioplegia. During a three-year period, we observed increases of up to 200% in the flow rate of 8 of 11 saphenous vein grafts in 7 patients who underwent reoperation for bleeding or cardiac tamponade in the early postoperative period. At initial operation, flow rates ranged from 25 ml/min to 130 ml/min (mean value, 66.8 +/- 10.3 ml/min [standard error of the mean]). At reexploration, flow measurements ranged from 0 ml/min (graft clotted) to 260 ml/min (mean value, 110 +/- 22.8 ml/min). This difference was statistically significant (p less than 0.02). This study documents that flow rate measurements in saphenous vein aorotocoronary bypass grafts can increase in the early postoperative period although the exact mechanism by which this occurs is not known.
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D002305:Cardiac Tamponade / Q000601:surgery; D001026:Coronary Artery Bypass; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000502:physiology; D005260:Female; D006324:Heart Arrest, Induced; D006470:Hemorrhage / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000601:surgery; D011184:Postoperative Period; D012501:Saphenous Vein / Q000502:physiology / Q000637:transplantation; D013514:Surgical Procedures, Operative; D014182:Transplantation, Autologous; D014655:Vascular Resistance