title: Lipiodol and dye at the site of ablation decreases during RFA.
abstract: OBJECTIVE
  Intrahepatic metastasis is one of the serious complications of radiofrequency ablation (RFA) therapy for hepatocellular carcinoma. The aim of this study was to investigate how liver tissue could be disseminated during the RFA procedure with different devices and protocols in an in vivo porcine model.
  
  
  METHODS
  Three pigs underwent RFA procedures using 2 different devices: needles that could be expanded (LeVeen needle) and those that could not (cool-tip needle). A LeVeen needle was used with a single-step full extension method or a stepwise extension method. Before RFA, a mixture of lipiodol and blue dye was injected intrahepatically into a precoagulated area. After the ablation procedure, the specimen was cut to evaluate the amount of dye remaining in the ablated region and the distribution of the dye outside the ablated area.
  
  
  RESULTS
  The stepwise extension method resulted in the disappearance of the smallest amount of the dye and lipiodol at the ablation site, compared with the full extension method and cool-tip needle. Dye was found at sites distant from the ablated area in all cases using the cool-tip needle, but in none with the stepwise extension method.
  
  
  CONCLUSIONS
  The stepwise procedure using the expandable needle can reduce tumor cell scattering, which can cause intrahepatic metastasis, compared with other methods.
authors.affiliation: Department of Hepatology, Toranomon Hospital, Tokyo, Japan.
authors.forename: Miharu
authors.initials: M
authors.lastname: Hirakawa
authors.forename: Kenji
authors.initials: K
authors.lastname: Ikeda
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kawamura
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hosaka
authors.forename: Hiromi
authors.initials: H
authors.lastname: Yatsuji
authors.forename: Hitomi
authors.initials: H
authors.lastname: Sezaki
authors.forename: Norio
authors.initials: N
authors.lastname: Akuta
authors.forename: Satoshi
authors.initials: S
authors.lastname: Saitoh
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Suzuki
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Yasuji
authors.initials: Y
authors.lastname: Arase
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Kumada
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000009:adverse effects* / Q000379:methods*; D004396:Coloring Agents / Q000378:metabolism*; D005260:Female; D007459:Iodized Oil / Q000378:metabolism*; D008099:Liver / Q000601:surgery*; D009362:Neoplasm Metastasis / Q000517:prevention & control; D013194:Staining and Labeling / Q000379:methods*; D013552:Swine
chemical_list: D004396:Coloring Agents; D007459:Iodized Oil