Inflammatory factors in neonatal renal tissue after cardiopulmonary bypass

Objectives: Still is little known about the direct effects of cardiopulmonary bypass and hypothermia on several organs, especially in the neonate. The aim of the study was to identify inflammatory factors in renal tissue after cardiopulmonary bypass and deep hypothermic circulatory arrest.

Methods: The kidneys of newborn piglets were explanted after a hemodynamic stable period of 6 hours after cardiopulmonary bypass (CPB). The piglets were on CPB for 180 minutes. Four animals underwent mild hypothermia (32°C) and cardioplegic cardiac arrest (CPB group). Five animals underwent deep hypothermic circulatory arrest (18°C; DHCA group). The explanted kidneys were examined regarding tissue granulocytes, tissue activity of tumor necrosis factor alpha (TNF-alpha), and apoptosis. Then, the data were compared with the data of normal neonatal kidneys (control; n=6).

Results: The granulocytes count was in the renal tissue of CPB group statistically significant higher if compared to the normal neonatal renal tissue (CPB vs. control 29.8±22.5 vs. 6.7±3.3; p<0.05). The TNF-alpha activity did not reach statistically significant differences between the groups. The amount of apoptosis was in CPB group higher than in control (10.3±9.0 vs. 0.8±1.2; p<0.05).

Conclusions: In comparison to the normal neonatal renal tissue significant increased amounts of granulocytes and apoptotic cells were found after CPB.