Mini Bypass and Proinflammatory Leukocyte Activation: A Randomized Controlled Trial.

Area of Science:

• Cardiovascular Surgery
• Immunology
• Biochemistry

Background:

• Conventional cardiopulmonary bypass (CPB) during CABG surgery triggers systemic inflammation.
• The specific intracellular pathways involved and CPB's impact remain unclear.
• Miniaturized CPB (mCPB) may mitigate this inflammatory response.

Purpose of the Study:

• To compare the effects of mCPB versus conventional CPB (cCPB) on inflammatory markers.
• To investigate the induction of reactive oxygen species (ROS) and activation of nuclear factor (NF)-κB and p38 mitogen-activated protein kinase (MAPK) in leukocytes.
• To assess leukocyte accumulation and systemic inflammatory markers.

Main Methods:

• Randomized trial of CABG patients assigned to cCPB (n=13) or mCPB (n=13).
• Blood samples collected preoperatively and post-CPB initiation (up to 5 hours).
• Flow cytometry used to analyze intracellular ROS, p38-MAPK, and NF-κB phosphorylation in leukocytes.

Main Results:

• Lymphocyte ROS levels were significantly lower with mCPB compared to cCPB.
• p38-MAPK activation was reduced in the mCPB group post-CPB initiation.
• No significant differences in NF-κB phosphorylation, leukocyte accumulation, or CRP levels between groups.
• Lower postoperative serum creatinine levels observed in the mCPB group.

Conclusions:

• mCPB attenuates p38-MAPK activation and ROS generation compared to cCPB.
• These findings suggest a potential mechanism for reduced inflammation with CPB miniaturization.
• mCPB may offer renal protection compared to cCPB.