What is the difference in ablation zone of multi-bipolar radiofrequency ablation between liver cirrhosis and normal liver background? - a prospective clinical study

Purpose To explore the differences in ablation zone between liver cirrhosis and normal liver background and investigate the effect of hepatic blood flow on ablation zone of RFA. Methods Between 2017 and 2019, 203 patients who had liver malignancies and underwent percutaneous RFA with Celon bipolar electrodes enrolled into this study. There were 90 patients had liver cirrhosis and 113 patients had normal liver background. They were 63 females and 140 males with average age of 59.0 +/- 10.9 years old. Contrast-enhanced CT/MRI was used to evaluate the ablation zone in one month after RFA. The hepatic flow measurements on CDFI and CEUS were performed before RFA. Correlations between ablation zone versus hepatic flow were assessed using multiple linear regression analysis. Results The average ablation zone in cirrhotic liver was significantly larger than those in normal liver background with 3 cm tip of RF electrodes (length 3.5 +/- 0.5 vs 3.1 +/- 0.4 cm, p = 0.001; width 2.6 +/- 0.3 vs 2.2 +/- 0.3 cm, p < 0.001; thickness 2.5 +/- 0.3 vs 2.0 +/- 0.2 cm, p < 0.001). The similar result was found with three 4 cm tip of RF electrodes (width 3.6 +/- 0.5 vs 3.1 +/- 0.5 cm, p = 0.019; thickness 3.3 +/- 0.5 vs 2.7 +/- 0.5 cm, p = 0.002). The multiple linear regression analysis showed arrive time of hepatic vein and portal vein was statistically associated with ablation zone with 3 cm electrodes (p < 0.001, p = 0.001), but explained part of the variance (Adjusted R-2=0.294, adjusted R-2=0.212). Conclusion The ablation zones of RFA with multi-bipolar electrodes in liver cirrhosis were significantly larger than those in normal liver background, being up to 6 mm in thickness. The hepatic flow parameters partly contributed to the ablation zone.