Bacterial translocation in a rat model of large volume hepatic radiofrequency ablation.

Background: In this experimental study, we investigated the possibility of bacterial translocation, constituting a potential cause of infectious complications, after performing large volume hepatic radiofrequency ablation (RFA).

Materials And Methods: Wistar rats were subjected to RFA of the left median liver lobe (approximately 28.5% of the liver volume) after midline laparotomy. At 30 min, 24 h, 48 h, 72 h or 1 wk postoperatively, (1) blood samples were collected from the portal and systemic circulation for assessment of endotoxin concentration, (2) tissue specimens were excised from mesenteric lymph nodes, non-ablated liver, pancreas, spleen, kidneys, and lungs for bacterial culture, and (3) segments of terminal ileum were excised for histopathologic examination, morphometric analysis, and apoptotic and mitotic rate estimation. At 1 and 48 h, ileal mucosa was collected for oxidative state assessment on the basis of glutathione to glutathione disulfate (GSH/GSSG) ratio.

Results: Endotoxin levels were increased in both the portal and systemic circulation. Intestinal bacteria were isolated from all the organs at all time points. Ileal mucosa became gradually atrophic, with a decrease in villous height and density. There was an increase of crypt apoptotic rate, a decrease of GSH/GSSG ratio, while there were only mild signs of inflammation.

Conclusions: Large volume liver RFA in the rat resulted to endotoxemia and translocation of intestinal bacteria to proximal and distal to the intestine organs at both the early and late post-RFA periods. The intestinal mucosa barrier was disrupted as suggested by ileal mucosal atrophy, increased crypt apoptosis, and induction of oxidative stress.