Background:

Extracorporeal circulation (ECC) is indispensable for cardiac surgery. Despite the fact that ECC causes non-physiological damage to blood components, its pathophysiology has not been fully elucidated. In our previous study, we constructed a rat ECC system and observed a systemic inflammatory response during and after blood tests assessing ECC, while the damage per organ localization caused by ECC was not examined. In this study, we used a rat model to assess the gene expression of inflammatory cytokines in major organs during ECC.

Methods:

The ECC system consisted of a membranous oxygenator, tubing line, and a small roller pump. Rats were divided into a SHAM (which received surgical preparation only, without ECC) group and an ECC group. Proinflammatory cytokines were measured using real-time PCR in major organs after ECC to evaluate local inflammatory responses in the organs. 

Results:

Interleukin (IL)-6 levels were significantly elevated in the ECC group compared to the SHAM group, especially in the heart and lungs. 

Conclusions:

This study suggests that ECC promotes organ damage and the inflammatory response, but the degree of gene expression of proinflammatory cytokines varies from organ to organ, suggesting that it does not uniformly cause organ damage.