title: Bimodal electric tissue ablation (BETA) compared with the Cool-Tip RFA system.
abstract: BACKGROUND
  Bimodal electric tissue ablation (BETA) incorporates the process of electrolysis into radiofrequency ablation (RFA) to increase the size of tissue ablation. This study investigated whether BETA could increase the efficacy of the Cool-Tip RF system (Covidien, Boulder, CO, USA) to produce larger ablations. It also investigated whether applying electrolysis only during the pretreatment phase (called electrochemical treatment (ECT)/RFA group) is as effective as BETA (where electrolysis was used during both the pretreatment and RFA phases).
  
  
  METHODS
  A Cool-Tip RF system (Covidien) was used to test three types of ablations (RFA, BETA, and ECT/RFA) in a pig liver model. In BETA, 9 V of direct current was provided for 10 min, after which the RF generator was started and both electrical circuits were allowed to run concurrently. In ECT/RFA, however, the direct current circuit was switched off after 10 min of pretreatment and only RFA was performed as described above. Ablation sizes were measured in three dimensions.
  
  
  RESULTS
  The size of ablations (transverse diameter A and B) produced by BETA and ECT/RFA was significantly larger compared with standard RFA (P < 0/001). BETA also created larger ablations compared with ECT/RFA (P < 0.001).
  
  
  CONCLUSIONS
  BETA could improve the efficacy of the Cool-Tip RF system (Covidien) to achieve larger ablations. The increased tissue hydration improved delivery of electrical energy to the tissues and delayed the process of desiccation, thus allowing the ablation process to continue for longer periods of time to produce larger ablations. BETA could be used to treat larger liver tumours more effectively than standard RFA.
authors.affiliation: University of Adelaide Discipline of Surgery, The Queen Elizabeth Hospital, Adelaide, South Australia, Australia.
authors.forename: Leong Ung
authors.initials: LU
authors.lastname: Tiong
authors.forename: John B F
authors.initials: JB
authors.lastname: Field
authors.forename: Guy J
authors.initials: GJ
authors.lastname: Maddern
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D005260:Female; D008099:Liver / Q000473:pathology / Q000601:surgery*; D034421:Sus scrofa