Baseline flow in coronary bypass grafts.

Background: The purpose of the study is to estimate the total blood flow in coronary artery bypass grafts.

Methods: In a 3-year period 102 patients having a standardized coronary artery bypass grafting (CABG) with the left internal mammary artery (LIMA) anastomosed to the left anterior descending artery and a sequential vein grafted to the remaining diseased coronary arteries were included in the study, 21 females and 81 males. In females a mean of 3.9 anastomosis (range 2-5) were performed and in males a mean of 4.2 (range 2-6) were performed. Flow in the bypass grafts was measured with the transit-time method before termination of cardiopulmonary bypass.

Results: Females: LIMA 31 mL/min, vein graft 74 mL/min (26 mL/min per anastomosis), cumulated flow 105 mL/min. Males: LIMA 31 mL/min, vein graft 93 mL/min (29 mL/min per vein anastomosis), cumulated flow 124 mL/min.

Conclusion: Conventional CABG may restore half of the normal resting coronary artery blood flow (250 mL/min).