title: Enhancement of radiofrequency ablation of the liver combined with transarterial embolization using various embolic agents.
abstract: OBJECTIVE
  Reducing blood flow in the liver during radiofrequency ablation causes enlargement of the ablation area. In this animal study, we evaluated the extended effects of radiofrequency ablation combined with transarterial embolization using various embolic agents.
  
  
  METHODS
  We treated 38 radiofrequency ablation lesions after embolization in 13 pigs using the following embolic agents: gelatin sponge (Group A); iodized oil followed by gelatin sponge (Group B); 700-900 µm calibrated microspheres (Group C); and 100-300 µm calibrated microspheres (Group D). Lesion size and pathological evaluations of these ablation lesions were compared with those receiving radiofrequency ablation alone (control).
  
  
  RESULTS
  Both the long- and short-axis diameters of the ablation lesions for Groups A, B, C, and D were significantly longer than those of controls (long axis/short axis for Groups A, B, C, D, and controls were 27.2/23.2, 30.2/26.0, 28.2/22.2, 32.0/24.4, and 23.2 mm/18.5 mm, respectively) (P < 0.05). The long-axis of the ablation lesion for Group D was significantly longer than those for both Groups A and C (P < 0.05). At pathological examination, the central ablation lesions showed coagulative necrosis with a surrounding hemorrhagic rim, and the microspheres were fitted to occlude the small arteries in peripheral liver parenchyma in Groups C and D.
  
  
  CONCLUSIONS
  The extended effects of embolization with small microspheres may be stronger than those with large microspheres and were equal to those with iodized oil followed by gelatin sponge.
authors.affiliation: Department of Hepatobiliary and Pancreatic Oncology, Kanagawa Cancer Center, 2-3-2 Nakao, Asahi-ku, Yokohama, 241-8515, Japan.
authors.forename: Kuniyasu
authors.initials: K
authors.lastname: Irie
authors.forename: Manabu
authors.initials: M
authors.lastname: Morimoto
authors.forename: Kazushi
authors.initials: K
authors.lastname: Numata
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kondo
authors.forename: Satoshi
authors.initials: S
authors.lastname: Moriya
authors.forename: Yu
authors.initials: Y
authors.lastname: Shimoyama
authors.forename: Akito
authors.initials: A
authors.lastname: Nozaki
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Goda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Makoto
authors.initials: M
authors.lastname: Ueno
authors.forename: Shinichi
authors.initials: S
authors.lastname: Ohkawa
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Tanaka
authors.forename: Shin
authors.initials: S
authors.lastname: Maeda
mesh_terms: D000818:Animals; D017115:Catheter Ablation; D004621:Embolization, Therapeutic; D005260:Female; D008099:Liver / Q000098:blood supply / Q000473:pathology* / Q000601:surgery*; D013552:Swine