Experimental study of large-volume microwave ablation in the liver

Background: Microwave coagulation therapy is useful in the destruction of small, irresectable liver tumours of primary and secondary origin. Unfortunately, the small lesion size produced by currently available equipment makes it difficult and time consuming completely to ablate lesions larger than 3 cm in diameter. A microwave system capable of producing large-volume ablations in very short periods of time has been developed. Using a large-animal model the ability of the equipment to produce large-volume lesions in a safe, predictable and dose-dependent manner was tested. Methods: Fourteen large white pigs were anaesthetized and underwent multiple microwave treatments. The animals were killed at different timepoints to investigate lesion size and evolution. Results: The microwave system was able to generate large-volume ablations of up to 6.5 cm in diameter in a controlled and dose-dependent manner. Conclusion: This novel microwave system allows the ablation of large volumes of liver tissue in a short period of time. The ability to produce lesions reproducibly and safely highlights the potential of this system in the future treatment of irresectable liver tumours.