Figure 1: Axial CT image before radiofrequency ablation of a liver metastasis (star) is shown.
Figure 2: Axial CT image immediately after the RFA shows a small subcapsular hematoma anterior to the right hepatic lobe (arrows). Note hyperattenuation change at the tumor site (star), which is expected after the RFA.
Vascular complications of RFA
- Portal vein thrombosis (0.7%)
- Subcapsular hematoma (0.7%)
- Hepatic vein thrombosis
- Hepatic infarction
- Thrombosis of vessel occurs as a result of 'heat-sink' effect to the flowing blood. Smaller caliber vessels are prone to thrombose due to thermal damage from RF ablation
- On US, or CT, thrombosis is visualized as filling defects
- Hepatic parenchyma may show segmental enhancement peripheral to the affected veins
- Most thrombosis is self limited
- Subcapsular hematoma usually is related to placement of electrodes or underlying coagulopathy.