Fig. 8. RF ablation using bypass targeting technique in 66-year-old man.

A. Pre-RF ablation contrast-enhanced CT image shows HCC (curved arrow) in segment 1 near main portal vein and inferior vena cava (IVC) and right portal vein (arrowhead) on expected approach path (dotted arrow) of electrode. B. Intercostal US image demonstrates hypoechoic HCC (curved arrow) between main portal vein and IVC in segment 1. Note that right portal vein (arrowhead) blocks approach path for needle insertion into index tumor. C. Contrast-enhanced CT image obtained from 5 mm below level of A depicts safe approach path (dotted arrow) without traversing right portal vein. D. Serial schematic illustrations show process of placing electrode while bypassing large vessel in front of target tumor using structural flexibility of liver. HCC = hepatocellular carcinoma, RF = radiofrequency, US = ultrasound E. Intercostal US image during procedure shows that electrode (arrowhead) is safely placed within index tumor (arrow) using bypass targeting without puncturing right portal vein. F. Immediate follow-up contrast-enhanced CT image reveals low-attenuated RF ablation zone (asterisk) and intact right portal vein (arrowhead) with no signs of penetration by electrode. RF = radiofrequency, US = ultrasound