title: Radiofrequency ablation during continuous saline infusion can extend ablation margins.
abstract: OBJECTIVE
  To determine whether fluid injection during radiofrequency ablation (RFA) can increase the coagulation area.
  
  
  METHODS
  Bovine liver (1-2 kg) was placed on an aluminum tray with a return electrode affixed to the base, and the liver was punctured by an expandable electrode. During RFA, 5% glucose; 50% glucose; or saline fluid was infused continuously at a rate of 1.0 mL/min through the infusion line connected to the infusion port. The area and volume of the thermocoagulated region of bovine liver were determined after RFA. The Joule heat generated was determined from the temporal change in output during the RFA experiment.
  
  
  RESULTS
  No liquid infusion was 17.3 ± 1.6 mL, similar to the volume of a 3-cm diameter sphere (14.1 mL). Mean thermocoagulated volume was significantly larger with continuous infusion of saline (29.3 ± 3.3 mL) than with 5% glucose (21.4 ± 2.2 mL), 50% glucose (16.5 ± 0.9 mL) or no liquid infusion (17.3 ± 1.6 mL). The ablated volume for RFA with saline was approximately 1.7-times greater than for RFA with no liquid infusion, representing a significant difference between these two conditions. Total Joule heat generated during RFA was highest with saline, and lowest with 50% glucose.
  
  
  CONCLUSIONS
  RFA with continuous saline infusion achieves a large ablation zone, and may help inhibit local recurrence by obtaining sufficient ablation margins. RFA during continuous saline infusion can extend ablation margins, and may be prevent local recurrence.
authors.affiliation: Department of Gastroenterology and Hepatology, Saiseikai Niigata Daini Hospital, Niigata 950-1104, Japan. toruishi@ngt.saiseikai.or.jp
authors.forename: Toru
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Kubota
authors.forename: Ryoko
authors.initials: R
authors.lastname: Horigome
authors.forename: Naruhiro
authors.initials: N
authors.lastname: Kimura
authors.forename: Hiroki
authors.initials: H
authors.lastname: Honda
authors.forename: Akito
authors.initials: A
authors.lastname: Iwanaga
authors.forename: Keiichi
authors.initials: K
authors.lastname: Seki
authors.forename: Terasu
authors.initials: T
authors.lastname: Honma
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Yoshida
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation; D002417:Cattle; D004566:Electrodes; D004867:Equipment Design; D007263:Infusions, Parenteral; D008099:Liver / Q000473:pathology / Q000601:surgery*; D023421:Models, Animal; D012965:Sodium Chloride / Q000008:administration & dosage*; D013997:Time Factors
chemical_list: D012965:Sodium Chloride
keywords: Ex vivo bovine liver; Glucose; Joule heat; Large ablation zone; Radiofrequency ablation; Saline