Liver regeneration following radiofrequency ablation.

Background: Radiofrequency ablation (RFA) of the liver leads to reduction of liver parenchymal volume. We sought to evaluate the regenerative response of the liver following RFA.
Materials and Methods: Thirty healthy New Zealand white rabbits were subjected to a single session liver RFA using a cool-tip electrode after midline laparotomy. The regenerative process of the liver was assessed at various time-points (0 h, 48 h, 1 wk, 3 wk, 10 wk) in terms of computed tomography-based liver volume measurements, histological examination, hepatocyte mitotic activity, and serum biochemistry.
Results: According to computed tomography-measurements, intact liver volume was gradually restored to the initial liver volume by the 10th week, while liver ablated volume was confined down to 50% of the initial ablated volume. At histology, inflammation, edema, and hepatocellular necrosis in the intact liver parenchyma, noted at 48 h, started to regress by 1 wk. Mitotic activity, initiated by 48 h, was substantially increased at 1 wk and remained high up to the 10th week. Serum transaminase levels were elevated up to 1 wk.
Conclusions: Liver RFA triggers a slow but sustained regenerative response of the liver with subsequent delayed restoration of parenchymal volume, while the ablated volume is gradually condensed.