**3.3 Complications after RFA**

182 Liver Tumors

starting the ablation. RFA causes changes in the coagulated liver parenchyma, which will affect further proper positioning of the probe under US-guidance (Figure 6). The geometry of overlapping ablations can vary widely, and they should be planned with respect of the size of the target lesion. A well-designed protocol for RFA of larger lesions should be used

Fig. 6. IOUS images. Isoechoic liver metastasis with hypoechoic rim before treatment (A). The lesion is punctured with the LeVeen needle electrode and ablation started (B). The RFA

To date the physiologic response of large-volume RFA (Figure 7), has not reported to be different from the more limited "usual" ablation volumes in clinical practice. However the

Fig. 7. Computed tomography of a patient with colorectal liver metastases before (A) and one week after large-volume RFA (B). Posttreatment follow-up CT of a patient two weeks

in order to ensure high success rate of complete ablation (Chen et al, 2004).

safety limit of clinical RFA of the liver remains unknown.

(C) and 6 months (D) after large volume RFA.

cycle is finished (C).

The postoperative care after RFA does not require specific treatment, irrespective whether RFA is performed as a sole procedure or simultaneously with various hepatic and/or extrahepatic resections. However the possibility of a potential life-threatening complication after RFA should always be kept in mind (Figure 8).

Fig. 8. Computed tomography of a patient after simultaneously performed bowel and liver resection plus RFA. Hepatic abscesses occurred at resection- and RFA sites (arrows).

Although RFA of the liver is a well-tolerated and safe procedure, complications and rarely death may occur after RFA-treatment. The most common complications after RFA of the liver are bleeding, abscessus and biloma formation and they sometimes may be fatal (Enne et al, 2003). The life-threatening complications from the thermal injury of organs adjacent to the liver were reported mainly for percutaneous RFA. Surgical approaches permit protection and isolation of endangered organs from inadvertent burn injury during hepatic RFA. In patients with cirrhosis, delayed portal vein thrombosis can occur after RFA near the main portal vein branches. Rare complication as a gas gangrene after RFA was also reported (Kvitting et al, 2006). Any complication after hepatic RFA require immediate treatment and when necessary interventions (surgical or image-guided) should be regarded as life saving and performed without delay. This approach permits avoiding mortality even in most critical situations (Julianov, 2008)
