title: Influence of surgical staples on radiofrequency ablation using multitined expandable electrodes.
abstract: OBJECTIVE
  During radiofrequency ablation (RFA), there is a risk that the multitined expandable electrode will come into contact with one of the surgical staples used to treat local recurrence after surgical operations. Our objective was to evaluate whether a surgical staple would influence the RFA of egg white using a multitined expandable electrode.
  
  
  METHODS
  Multitined expandable electrodes, LeVeen needles (expandable diameter 3.0 cm), were sunk into an egg white bath with (a) no surgical staple, (b) a surgical staple touching one of the tines, or (c) a surgical staple touching two of the tines simultaneously. By connecting the LeVeen needle and copper plate at the bottom of the bath, RFA was then performed on the egg whites as a substitute for human tissue. Ten egg white baths were ablated under each of conditions (a), (b), and (c), for a total of 30 sets of coagulated egg white.
  
  
  RESULTS
  There was no significant difference in the time from the power-on to the roll-off (i.e., the completion and shutting off of the electric circuit) or in the maximum diameter of the thermal lesion between conditions (a) and (b) or (a) and (c). However, the minimum diameter of the thermal lesion was significantly smaller in (c) compared with (a) (p < 0.01).
  
  
  CONCLUSIONS
  Surgical staples have the capacity to interfere with the electromagnetic field and decrease the minimum diameter of the thermal lesion in the event that a staple touches two of the tines of a multitined expandable electrode during RFA. Although the difference might be small enough to be neglected under many clinical circumstances, we recommend that, if possible, the tines not be expanded near metallic material.
authors.affiliation: Department of Radiology, Hokkaido University School of Medicine, N-15, W-7, Kita-ku Sapporo, Hokkaido 060-8638, Japan. YRB03514@nifty.com
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sakuhara
authors.forename: Tadashi
authors.initials: T
authors.lastname: Shimizu
authors.forename: Daisuke
authors.initials: D
authors.lastname: Abo
authors.forename: Yu
authors.initials: Y
authors.lastname: Hasegawa
authors.forename: Fumi
authors.initials: F
authors.lastname: Kato
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Kodama
authors.forename: Hiroki
authors.initials: H
authors.lastname: Shirato
mesh_terms: D000818:Animals; D017115:Catheter Ablation; D002645:Chickens; D004529:Egg White; D004553:Electric Conductivity; D004566:Electrodes; D004867:Equipment Design; D013537:Sutures / Q000009:adverse effects*; D013696:Temperature; D013814:Thermal Conductivity