title: Hepatic ablation using bipolar radiofrequency electrocautery.
abstract: OBJECTIVE
  Percutaneous methods have been used to treat primary and secondary hepatic neoplasms. In the current study, we evaluated the potential of bipolar radiofrequency (RF) electrocautery to increase in vitro liver tissue destruction when compared with monopolar RF electrocautery.
  
  
  METHODS
  Two needles (electrodes) were placed into fresh bovine liver tissue for use with bipolar electrocautery. Needle tip exposure was kept constant at 3 cm while other parameters, including treatment time, power (wattage), interneedle distance, and needle tip temperature, were changed. Pathologic and histologic correlation was performed, and tissue necrosis was weighed in grams for individual parameters.
  
  
  RESULTS
  There was a minimal threshold of approximately 45 degrees C where tissue coagulation occurred. Tissue coagulation increased the longer treatment went on. Increasing temperature, wattage, or both increased tissue coagulation such that necrosis was too rapid and char formation occurred, which prevented further coagulation. For all wattages and temperatures, there was increasing tissue necrosis with increasing needle separation, until a point at which further needle separation produced less tissue necrosis. Optimizing parameters allowed tissue coagulation of greater than 30 g.
  
  
  CONCLUSIONS
  Bipolar RF electrocautery shows promise for increasing the tissue coagulation in fresh bovine liver compared with the previously described monopolar technique.
authors.affiliation: Department of Radiology, University of California Davis Medical Center, Sacramento 95817, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: McGahan
authors.forename: W Z
authors.initials: WZ
authors.lastname: Gu
authors.forename: J M
authors.initials: JM
authors.lastname: Brock
authors.forename: H
authors.initials: H
authors.lastname: Tesluk
authors.forename: C D
authors.initials: CD
authors.lastname: Jones
mesh_terms: D000818:Animals; D002417:Cattle; D004564:Electrocoagulation / Q000379:methods*; D004567:Electrodes, Implanted; D008099:Liver / Q000473:pathology / Q000601:surgery*; D008113:Liver Neoplasms / Q000601:surgery; D009336:Necrosis