We aimed to compare the inflammatory cytokines levels of the miniaturized and conventional extracorporeal circuit system. The miniaturized extracorporeal circuit system may be fewer possible inflammation-induced or blood transfusion-related complications.

We performed a prospective randomized controlled trial (RCT) of 101 patients undergoing congenital heart surgery with CPB (cardiopulmonary bypass, weight ≤15 kg, age ≤2 years). Patients were divided into two different CPB groups randomly by random data form. Blood samples at five different time points and the ultrafiltration fluid before and after CPB were collected in all patients. IL-6, IL-8, and TNF alpha were respectively tested with Abcam ELISA kit.

The IL-6 level of blood serum in two groups had no statistical differences between the two groups at all time points. The IL-8 level of blood serum in two groups had no statistical differences right after anesthesia and 5 min after CPB. However, IL-8 level was significantly higher in conventional extracorporeal circuit group than that in miniaturized extracorporeal circuit group at 6 h, 12 h and 24 h after CPB. Blood serum TNF alpha in conventional extracorporeal circuit group was significantly higher at 6 h after CPB than that in miniaturized extracorporeal circuit group. No statistical differences in TNF alpha were found between two groups right after anesthesia and at 5 min after CPB, 12 h and 24 h after CPB. In ultrafiltration fluid, no statistical differences were found in IL-6, IL-8 nor TNF alpha between two groups in all time. No statistical differences were found in ICU (intensive care unit) stay and mechanical ventilation time between the two groups. The blood transfusion rate was significantly lower in miniaturized extracorporeal circuit group.

Implementing the miniaturized extracorporeal circuit system could decrease the inflammatory cytokines at a certain level. The blood transfusion rate is significantly lower in miniaturized extracorporeal circuit group This indicates the miniaturized extracorporeal circuit system might be a safer CPB strategy with fewer possible inflammation-induced or blood transfusion-related complications.