Original Articles
Copyright ©2009 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Jul 14, 2009; 15(26): 3232-3239
Published online Jul 14, 2009. doi: 10.3748/wjg.15.3232
Cystic echinococcosis of the liver and lung treated by radiofrequency thermal ablation: An ex-vivo pilot experimental study in animal models
Vincenzo Lamonaca, Antonino Virga, Marta Ida Minervini, Roberta Di Stefano, Alessio Provenzani, Pietro Tagliareni, Giovanna Fleres, Angelo Luca, Giovanni Vizzini, Ugo Palazzo, Bruno Gridelli
Vincenzo Lamonaca, Marta Ida Minervini, Alessio Provenzani, Pietro Tagliareni, Giovanna Fleres, Angelo Luca, Giovanni Vizzini, Ugo Palazzo, Bruno Gridelli, Roberta Di Stefano, ISMETT (Mediterranean Institute for Transplantation and Advanced Therapies), University of Pittsburgh Medical Center Italy, Via E. Tricomi 1 - 90127 Palermo, Italy
Antonino Virga, Health Care Department of Region of Sicily, Veterinary Service, Piazza O. Ziino 24 - 90141 Palermo, Italy
Author contributions: Lamonaca V designed, performed the study and wrote the paper; Virga A provided organ samples; Minervini MI performed the pathology and histology examination of the samples; Di Stefano R helped with data collection and storage; Provenzani A did the statistical analysis and edited the figures; Tagliareni P assisted during the RTA procedure and pathology sampling; Fleres G processed the pathology samples; Luca A provided radiology equipment; Vizzini G helped organize the study; Palazzo U coordinated different services in sample management; Gridelli B reviewed the paper.
Correspondence to: Vincenzo Lamonaca, MD, Clinical Assistant Professor of Medicine, ISMETT, University of Pittsburgh Medical Center Italy, Via E. Tricomi 1 - 90127 Palermo, Italy. vlamonaca@ismett.edu
Telephone: +39-91-2192111
Fax: +39-91-2192400
Received: March 28, 2009
Revised: May 27, 2009
Accepted: June 3, 2009
Published online: July 14, 2009
Abstract

AIM: To evaluate radiofrequency thermal ablation (RTA) for treatment of cystic echinococcosis in animal models (explanted organs).

METHODS: Infected livers and lungs from slaughtered animals, 10 bovine and two ovine, were collected. Cysts were photographed, and their volume, cyst content, germinal layer adhesion status, wall calcification and presence of daughter or adjacent cysts were evaluated by ultrasound. Some cysts were treated with RTA at 150 W, 80°C, 7 min. Temperature was monitored inside and outside the cyst. A second needle was placed inside the cyst for pressure stabilization. After treatment, all cysts were sectioned and examined by histology. Cysts were defined as alive if a preserved germinal layer at histology was evident, and as successfully treated if the germinal layer was necrotic.

RESULTS: The subjects of the study were 17 cysts (nine hepatic and eight pulmonary), who were treated with RTA. Pathology showed 100% success rate in both hepatic (9/9) and lung cysts (8/8); immediate volume reduction of at least 65%; layer of host tissue necrosis outside the cyst, with average extension of 0.64 cm for liver and 1.57 cm for lung; and endocyst attached to the pericystium both in hepatic and lung cysts with small and focal de novo endocyst detachment in just 3/9 hepatic cysts.

CONCLUSION: RTA appears to be very effective in killing hydatid cysts of explanted liver and lung. Bile duct and bronchial wall necrosis, persistence of endocyst attached to pericystium, should help avoid or greatly decrease in vivo post-treatment fistula occurrence and consequent overlapping complications that are common after surgery or percutaneous aspiration, injection and reaspiration. In vivo studies are required to confirm and validate this new therapeutic approach.

Keywords: Cystic echinococcosis, Hydatid cyst, Radiofrequency thermal ablation, Hepatic hydatidosis, Pulmonary hydatidosis