title: Influence of NaCl concentrations on coagulation, temperature, and electrical conductivity using a perfusion radiofrequency ablation system: an ex vivo experimental study.
abstract: OBJECTIVE
  To determine, by means of an ex vivo study, the effect of different NaCl concentrations on the extent of coagulation obtained during radiofrequency (RF) ablation performed using a digitally controlled perfusion device.
  
  
  METHODS
  Twenty-eight RF ablations were performed with 40 W for 10 min using continuous NaCl infusion in fresh excised bovine liver. For perfusion, NaCl concentrations ranging from 0 (demineralized water) to 25% were used. Temperature, the amount of energy, and the dimensions of thermal-induced white coagulation were assessed for each ablation. These parameters were compared using the nonparametric Mann-Whitney test. Correlations were calculated according to the Spearman test.
  
  
  RESULTS
  RF ablation performed with 0.9% to 25% concentrations of NaCl produced a mean volume of coagulation of 30.7 +/- 3.8 cm(3), with a mean short-axis diameter of 3.6 +/- 0.2 cm. The mean amount of energy was 21,895 +/- 1,674 W and the mean temperature was 85.4 +/- 12.8 degrees C. Volume of coagulation, short-axis diameter, and amount of energy did not differ significantly among NaCl concentrations (p > 0.5). A correlation was found between the NaCl concentration and the short-axis diameter of coagulation (r = 0.64) and between the NaCl concentration and the mean temperature (r = 0.67), but not between the NaCl concentration and volume of coagulation.
  
  
  CONCLUSIONS
  In an ex vivo model, continuous perfusion with high NaCl concentrations does not significantly improve the volume of thermal-induced coagulation. This may be because the use of a low-power generator cannot sufficiently exploit the potential advantage of better tissue conductivity provided by NaCl perfusion.
authors.affiliation: Department of Diagnostic Radiology, Eberhard Karls University, Tübingen, Germany. ChAube@chu-angers.fr
authors.forename: Christophe
authors.initials: C
authors.lastname: Aubé
authors.forename: Diethard
authors.initials: D
authors.lastname: Schmidt
authors.forename: Jens
authors.initials: J
authors.lastname: Brieger
authors.forename: Martin
authors.initials: M
authors.lastname: Schenk
authors.forename: Stefan
authors.initials: S
authors.lastname: Kroeber
authors.forename: Bruno
authors.initials: B
authors.lastname: Vielle
authors.forename: Claus D
authors.initials: CD
authors.lastname: Claussen
authors.forename: S Nahum
authors.initials: SN
authors.lastname: Goldberg
authors.forename: Philippe L
authors.initials: PL
authors.lastname: Pereira
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D017115:Catheter Ablation / Q000379:methods*; D002417:Cattle; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004553:Electric Conductivity; D004566:Electrodes; D004867:Equipment Design; D008099:Liver / Q000473:pathology / Q000601:surgery; D009336:Necrosis; D010477:Perfusion / Q000379:methods; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: D012965:Sodium Chloride