The Effect of Cardiopulmonary Bypass and Hypothermic Circulatory Arrest on Hepatic Histology in Newborn Animals: An Experimental Study

Still little is known about the effect of cardiac surgery on neonatal hepatic tissue. We examined the effect of cardiopulmonary bypass ( CPB ) and the effect of deep hypothermic circulatory arrest ( DHCA ) on neonatal hepatic tissue. Liver biopsies of neonatal piglets were taken after CPB ( n  = 4), after DHCA ( n  = 5), and after surgery without CPB (non‐ CPB ; n  = 3). Additionally, findings were compared to those of control piglets ( n  = 9). The liver specimens were fixed, stained with hematoxylin and eosin, and scored regarding inflammatory reaction, hepatocellular edema, and apoptosis. Inflammation score of treated groups was higher than in control; CPB 2.5 ± 0.5, DHCA 1.6 ± 0.4, non‐ CPB 1.2 ± 0.6, control 0.4 ± 0.3 ( P  < 0.001 CPB and DHCA vs. control; P  < 0.05 non‐ CPB vs. control). Hepatic cell edema was more evident after DHCA (score 2.0 ± 0.4 vs. 0.2 ± 0.3 in control and 0.6 ± 0.5 after CPB ; P  < 0.001 and P  < 0.05, respectively). The highest apoptotic cell count was in the non‐ CPB group (22.3 ± 6.3 vs. 11.4 ± 3.6 in control and 8.9 ± 5.4 after CPB ; P  < 0.05). The present study showed that (i) surgical trauma induces hepatic cell apoptosis; (ii) CPB increases hepatic inflammatory reaction; and (iii) DHCA amplifies hepatic cell edema.