title: Bipolar radiofrequency ablation using internally cooled electrodes in ex vivo bovine liver: prediction of coagulation volume from applied energy.
abstract: OBJECTIVE
  We sought to evaluate the relationship between parameters of bipolar radiofrequency (RF) ablation using internally cooled electrodes.
  
  
  METHODS
  Bipolar RF ablations (n = 24) were performed in ex vivo bovine liver using an internally cooled applicator with 2 electrodes located on the same shaft. The power-output was systematically varied (20-75 W). On the basis of our experimental data, mathematical functions were fitted and the goodness-of-fit was assessed by the parameter R.
  
  
  RESULTS
  The duration to induce an increase of tissue resistance and the amount of applied energy increased with a decreased power-output. The maximum short-axis was 4.5 cm (20 W) and required an application of 64 kilojoules (kJ). The volume of coagulation can be determined as a function of the duration of energy application (R = 0.954) and the amount of applied energy (R = 0.945).
  
  
  CONCLUSIONS
  The amount of applied energy and the duration of energy application can predict the volume of induced coagulation and may be useful to control internally cooled bipolar RF ablation.
authors.affiliation: Department of Diagnostic Radiology, Eberhard-Karls-University, Tübingen, Germany. stephan.clasen@med.uni-tuebingen.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Clasen
authors.forename: Diethard
authors.initials: D
authors.lastname: Schmidt
authors.forename: Klaus
authors.initials: K
authors.lastname: Dietz
authors.forename: Andreas
authors.initials: A
authors.lastname: Boss
authors.forename: Stefan M
authors.initials: SM
authors.lastname: Kröber
authors.forename: Christina
authors.initials: C
authors.lastname: Schraml
authors.forename: Jan
authors.initials: J
authors.lastname: Fritz
authors.forename: Claus D
authors.initials: CD
authors.lastname: Claussen
authors.forename: Philippe L
authors.initials: PL
authors.lastname: Pereira
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods; D002417:Cattle; D003080:Cold Temperature; D004566:Electrodes; D066298:In Vitro Techniques; D008099:Liver / Q000601:surgery*; D015233:Models, Statistical