What are the recommendations for using a cardiopulmonary bypass (CPB) pump in Coronary Artery Bypass Grafting (CABG)?

Recommendations for Cardiopulmonary Bypass (CPB) Pump in CABG

On-pump CABG should be considered the standard approach for most patients undergoing coronary artery bypass grafting due to better long-term outcomes, higher graft patency rates, and more complete revascularization compared to off-pump techniques. 1

Evidence Comparing On-Pump vs. Off-Pump CABG

• The ROOBY trial (largest RCT comparing these techniques) demonstrated that on-pump CABG was associated with better 1-year composite outcomes and higher graft patency rates (87.8% vs. 82.6%) compared to off-pump CABG 1
• On-pump CABG allows for more complete revascularization with a higher number of distal anastomoses per patient 2
• Long-term survival appears better with on-pump CABG using cardiopulmonary bypass and cardioplegic arrest 2
• On-pump CABG provides better access to coronary arteries in technically challenging locations, particularly those on the lateral left ventricular wall 1

Specific Patient Considerations

• Hemodynamically unstable patients: On-pump CABG is preferred as CPB provides support for systemic circulation 1
• Patients with extensive ascending aortic disease: Off-pump CABG with avoidance of aortic manipulation may be beneficial to reduce stroke risk 1, 3
• High-risk patients: Some evidence suggests mortality benefit with off-pump CABG in patients with predicted mortality risk >2.5%, though this remains controversial 1

Technical Aspects of CPB in CABG

• Several strategies have been developed to mitigate complications associated with CPB:
  • CPB circuits coated with materials that reduce complement and leukocyte activation 1
  • Heparin-bonded CPB tubing 1
  • Specialized leukocyte depletion filters in CPB circuits 1
  • Closed mini-circuits to minimize blood-air interface 1

Potential Advantages of On-Pump CABG

• Less technically complex procedure 1
• Better graft patency rates (87.8% vs 82.6%) 1
• More complete revascularization with higher number of grafts per patient 4
• Better long-term composite outcomes 1, 2

Potential Advantages of Off-Pump CABG

• Less bleeding and lower blood transfusion requirements 1, 4
• Shorter ICU stay and hospital length of stay 4
• Potential reduction in stroke risk when combined with no-touch aortic technique, particularly in patients with extensive aortic disease 3
• Reduced risk of post-operative atrial fibrillation in some studies 3

Common Pitfalls and Caveats

• Off-pump CABG has a steeper learning curve and outcomes are highly dependent on surgeon experience 5
• Lower-volume centers performing off-pump CABG have shown increased rates of mortality and reintervention 5
• Despite theoretical benefits, off-pump CABG has not consistently demonstrated reduced neurological complications or renal failure compared to on-pump techniques 5
• The number of vessels bypassed is typically lower with off-pump techniques, potentially leading to incomplete revascularization 4

Decision Algorithm

1. Standard approach: Use on-pump CABG for most patients requiring coronary revascularization 1
2. Consider off-pump CABG when:
   • Patient has extensive ascending aortic disease with high risk of stroke from manipulation 1
   • Surgeon has extensive experience with off-pump techniques 1
3. Strongly favor on-pump CABG when:
   • Patient is hemodynamically unstable 1
   • Complex coronary anatomy requires access to lateral wall vessels 1
   • Complete revascularization requires multiple grafts 2, 4

Based on current evidence, on-pump CABG remains the standard approach for coronary revascularization, with off-pump techniques reserved for specific clinical scenarios where the benefits may outweigh the risks.