Echinococcus cyst of liver and lung in animal models treated by radio-frequency thermal ablation. An ex vivo pilot experimental study

Abstract number: 1733_1262

Lamonaca V., Maruzzelli L., Minervini M., Virga N., Di Stefano R., Tagliareni P., Luca A., Sardina G., Vizzini G., Palazzo U., Gridelli B.

Background: Echinococcus cyst (EC) usually involves liver and lung. Treatment is surgery or PAIR (Percutaneous Aspiration, ethanol Injection and Reaspiration); infective complications and biliary fistulae, mainly due to proligera detachment, easily occur. Radio-frequency thermal ablation (RITA) is currently used for treatment of neoplasms, primarily HCCs.

Aim: evaluate RITA for treatment of EC of liver and lung, in animal models (explanted organs).

Materials and Methods: infected livers and lungs from slaughtered animals were studied. Cysts were photographed, classified, measured and had ultrasounds (US). Some of the cysts had RITA: 150 watt, 80°C, 7 minutes; just 1 liver and 2 lung cysts: 70°C, 7 minutes. During RITA, temperature was monitored in and outside. A second needle, placed inside the cyst, stabilised pressure. Both treated and untreated cysts were sectioned and examined by histology. Viability definition; alive cyst: clear fluid plus well preserved scolici and/or preserved germinal layer at histology; killed cyst: necrotic scolici and/or necrotic germinal layer at histology.

Results: 28 cysts were studied, 16 hepatic and 12 lung. US showed proligera adhese in 100% of hepatic and 75% of lung; focally detached in 25% of lung cysts. 17 cysts, 9 hepatic (average volume 40.5 ml) and 8 lung (average volume 137 ml) had RITA. The average of highest temperatures outside the cyst was 41.2°C (22.3–68.3) for liver and 49.3°C (38.8–55.0) for lung. The average extension of parenchymal necrosis outside the cyst was 0.64 cm (0–2) for liver, 1.57 cm (0.8–2.5) for lung. After RITA pathology showed: rate of killing 100% in hepatic (9/9) and 100% in lung cysts (8/8); proligera adhese in 67% (6/9) of hepatic and 75% (6/8) of lung cysts; focally detached in 33% (3/9) of hepatic and 25% of lung. 2 cysts, adjacent to treated ones, were killed despite no direct treatment; 1 more cyst was partially alive but the procedure was non-optimal (cyst broken). 11 cysts, 7 hepatic and 4 lung (average volume 30 ml), had no treatment. Pathology showed all of them alive and with proligera adhese.

Conclusion: Our study showed RITA is very effective in killing EC of explanted liver and lung. It causes limited damage to normal tissue, biliary duct damage, and keeps proligera attached. In vivo, RITA could be therapeutic with a lower incidence of post-procedure complications and probably also effective on external daughter/adjacent cysts. In vivo studies are required to confirm and validate such a new therapeutic approach.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
Back to top