Thermal protection of targeted air instillation in CT-guided radiofrequency ablation

To evaluate targeted intraperitoneal air instillation for the protection of adjacent structures at high-risk liver metastasis sites. On the basis of an interdisciplinary indication for radiofrequency ablation (RFA), targeted air instillation (up to 200 cc) was performed in 6 patients with a total of 6 liver metastases over an anterior or right lateral access route with a 22 G Chiba needle for the distension of the structures as well as protection against thermal damage from RFA in the close relationship of liver lesions to the stomach or colon. In 6 patients (mean age approximately 66.3 years, 4 males, 2 females) with a risky location of a colorectal metastasis (liver segment III or VI), the targeted air instillation was performed between the liver and stomach (4 / 6) and colon (2 / 6). Protection against thermal damage was able to be established in 6 / 6 liver metastases prior to RFA. All tumor sites were ablated completely without the occurrence of complications requiring treatment. The additional instillation of air into the peritoneum for distension and thermal protection is a useful extension of the RFA technique, which allows successful ablation at high-risk liver tumor sites and also allows interventional radiologists to treat tumor manifestations closely related to the colon or stomach. (orig.)