Bipolar radiofrequency ablation using internally cooled electrodes in ex vivo bovine liver: prediction of coagulation volume from applied energy.
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.
Clasen
Stephan
S
Department of Diagnostic Radiology, Eberhard-Karls-University, Tübingen, Germany. stephan.clasen@med.uni-tuebingen.de
Schmidt
Diethard
D
Dietz
Klaus
K
Boss
Andreas
A
Kröber
Stefan M
SM
Schraml
Christina
C
Fritz
Jan
J
Claussen
Claus D
CD
Pereira
Philippe L
PL
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