An experimental evaluation of ablation devices for the local treatment of the liver resection edge

Abstract

Surgical margin is the only technical variable that has an impact on long-term outcome after liver resection. In this study we compared radiofrequency (RFA), cryotherapy, diathermy and argon beam for the local treatment of liver resection edge. Methods Sixty eight ablations were produced on the surface of ex vivo sheep liver using the various modalities. Cryoablations were produced using both the Cryotech and the Erbe probes. Radiofrequency ablations were produced using a custom-made surface application probe and the RITA 1500 generator. Conmed 7500 system was used to produce diathermy and argon beam coagulation. Results Argon beam and the diathermy resulted in ablation to maximum depth of 3.5 mm with endpoint and spray modes at various power setting. RF ablation resulted in consistent ablations the diameter of which varied in a linear manner to the time of RF application and the depth of the ablations with the length of electrode deployment. Cryotherapy was as effective as RFA with both the cryotherapy systems but the Erbe trocar probe resulted in a deeper ablation, whereas the Cryotech paddle probe resulted in a larger diameter ablation. Conclusions RF and cryotherapy are equally effective as liver edge ablation device. Diathermy and argon are considered less effective. Cryotherapy requires expensive complex equipment that at least with liquid nitrogen systems requires to be prepared for use and this may not be available if the need for edge treatment during resection was unplanned.