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Flow in coronary bypass conduits on-pump and off-pump
Henrik K Kjaergard1, Akhmad Irmukhamedov, John B Christensen
1Department of Cardiothoracic Surgery, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark. henrik@dadlnet.dk
Insights
Coronary artery bypass grafting (CABG) on-pump and off-pump procedures showed no significant differences in blood flow through bypass conduits. On-pump CABG restores about half of normal coronary blood flow.
Area of Science:
- Cardiovascular Surgery
- Vascular Physiology
Background:
- Coronary artery bypass grafting (CABG) is a common surgical procedure.
- Assessing blood flow in bypass grafts is crucial for long-term graft patency and patient outcomes.
Purpose of the Study:
- To measure and compare blood flow in coronary artery bypass grafting conduits during on-pump versus off-pump procedures.
- To estimate the total blood flow provided by all bypass conduits in both surgical settings.
Main Methods:
- A study involving 120 on-pump and 97 off-pump CABG patients over 3.5 years.
- Utilized the transit-time method to measure blood flow in left internal mammary artery and saphenous vein grafts.
- Analyzed flow data separately for men and women.
Main Results:
- No significant differences in left internal mammary artery flow were observed between on-pump and off-pump procedures in men or women.
- Vein graft flow per anastomosis showed no significant differences between on-pump and off-pump in either sex.
- Mean conduit flows were consistently lower in women compared to men.
- Total conduit flow during on-pump CABG was higher in men (131.4 mL/min) than in women (108.4 mL/min).
Conclusions:
- Conduit blood flow is comparable between on-pump and off-pump coronary artery bypass grafting.
- On-pump CABG can restore approximately 50% of normal resting coronary blood flow (250 mL/min).
Background:
The purpose of the study was to measure the blood flow in coronary artery bypass grafting conduits on-pump and off-pump and to estimate the total conduit flow.
Methods:
In a 3.5-year period, 120 patients having coronary artery bypass grafting on-pump and 97 patients having coronary artery bypass grafting off-pump with the left internal mammary artery anastomosed to the left anterior descending artery and saphenous vein grafts to the remaining diseased coronary arteries were included in the study. Flow in the bypass conduits was measured with the transit-time method.
Results:
In men the left internal mammary artery flow (mean +/- standard error of the mean) was 33.7 +/- 2.0 mL/min on-pump and 34.4 +/- 2.9 off-pump (p > 0.05). In women the left internal mammary artery flow was 29.4 +/- 3.0 mL/min on-pump and 22.8 +/- 1.9 mL/min off-pump (p > 0.05). In men the vein graft flow per anastomosis was 30.4 +/- 1.3 mL/min on-pump and 37.8 +/- 5.4 mL/min off-pump (p > 0.05). In women the vein graft flow per anastomosis was 28.0 +/- 2.9 mL/min on-pump and 23.2 +/- 2.9 mL/min off-pump (p > 0.05). Consistently in women, the mean conduit flows were numerically lower than in men. In patients undergoing coronary artery bypass grafting on-pump the total conduit flows (left internal mammary artery plus vein grafts) were 131.4 +/- 2.5 mL/min in men and 108.4 +/- 3.2 mL/min in women.
Conclusions:
There were no major differences in conduit flow on-pump versus off-pump. Conventional coronary artery bypass grafting on-pump may restore up to approximately half of the normal resting coronary artery blood flow (250 mL/min).
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