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Published on: September 15, 2023
Comparison of inflammatory response during on-pump and off-pump coronary artery bypass surgery
Thomas Rimmelé1, Ramesh Venkataraman, Nicholas J Madden
1The CRISMA (Clinical Research, Investigation, and Systems Modeling of Acute Illness) Laboratory, Department of Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 1526, USA.
Insights
Modern extracorporeal circuits minimize inflammatory differences between on-pump and off-pump coronary artery bypass graft (CABG) surgery. The surgical procedure itself is the primary driver of the inflammatory response, not the bypass circuit.
Area of Science:
- Cardiovascular Surgery
- Immunology
- Biomaterials Science
Background:
- On-pump coronary artery bypass graft (CABG) surgery traditionally elicits a greater inflammatory response than off-pump CABG.
- Advancements in polymer-coated biocompatible extracorporeal circuits may alter this inflammatory profile.
Purpose of the Study:
- To investigate whether cardiopulmonary bypass, using modern extracorporeal circuits, still significantly contributes to the inflammatory response in CABG surgery.
- To compare the inflammatory response between on-pump and off-pump CABG procedures with advanced circuit technology.
Main Methods:
- Prospective observational study of 33 patients undergoing CABG (25 on-pump, 8 off-pump).
- Serial measurement of plasma cytokines (TNF, IL-6, IL-10) and procalcitonin.
- Collection of demographic, clinical, intra-operative, and post-operative data.
Main Results:
- Plasma levels of all measured inflammatory mediators (cytokines and procalcitonin) increased during surgery and normalized postoperatively.
- No significant differences in mediator levels were observed between the on-pump and off-pump CABG groups at any time point.
Conclusions:
- Modern polymer-coated biocompatible extracorporeal circuits result in an inflammatory response magnitude and pattern similar to off-pump CABG.
- The surgical procedure itself is the main contributor to the inflammatory response, with minimal impact from the extracorporeal circuit.
Purpose:
On-pump coronary artery bypass graft (CABG) surgery has been traditionally associated with a higher magnitude of inflammatory response than off-pump CABG. However with the development of polymer-coated biocompatible extracorporeal circuits, we wanted to see if cardiopulmonary bypass still played an important role in triggering this inflammatory response.
Methods:
In this prospective observational study, 33 patients undergoing CABG surgeries (25 on-pump and 8 off-pump patients) were studied. Serial plasma cytokine (TNF IL-6, IL-10) and procalcitonin concentrations were measured at different time-points during and after the surgery. Demographic and baseline clinical data, intra-operative management details and post-operative complications were also collected from the patients' charts.
Results:
Plasma levels of all 4 mediators increased during surgery and returned towards normal postoperatively. There were no differences between groups for any mediator at any time-point.
Conclusions:
We conclude that with the use of recent polymer-coated biocompatible extracorporeal circuits, the inflammatory response triggered by on-pump CABG becomes very similar in magnitude and pattern to that triggered by off-pump CABG. Thus, the surgical procedure contributes to most of the inflammatory response, with the extra-corporeal circuit having minimal to no effect on this response.
