title: No-Touch Radiofrequency Ablation: A Comparison of Switching Bipolar and Switching Monopolar Ablation inEx VivoBovine Liver.
abstract: To evaluate the feasibility, efficiency, and safety of no-touch switching bipolar (SB) and switching monopolar (SM) radiofrequency ablation (RFA) usingex vivobovine livers.
  
  
  
  A pork loin cube was inserted as a tumor mimicker in the bovine liver block; RFA was performed using the no-touch technique in the SM (group A1; 10 minutes, n = 10, group A2; 15 minutes, n = 10) and SB (group B; 10 minutes, n = 10) modes. The groups were compared based on the creation of confluent necrosis with sufficient safety margins, the dimensions, and distance between the electrode and ablation zone margin (DEM). To evaluate safety, small bowel loops were placed above the liver surface and 30 additional ablations were performed in the same groups.
  
  
  
  Confluent necroses with sufficient safety margins were created in all specimens. SM RFA created significantly larger volumes of ablation compared to SB RFA (allp< 0.001). The DEM of group B was significantly lower than those of groups A1 and A2 (allp< 0.001). Although thermal injury to the small bowel was noted in 90%, 100%, and 30% of the cases in groups A1, A2, and B, respectively, full depth injury was noted only in 60% of group A2 cases.
  
  
  
  The no-touch RFA technique is feasible in both the SB and SM modes; however, SB RFA appears to be more advantageous compared to SM RFA in the creation of an ablation zone while avoiding the unnecessary creation of an adjacent parenchymal ablation zone or adjacent small bowel injuries.
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.
authors.forename: Won
authors.initials: W
authors.lastname: Chang
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.; Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul 03080, Korea.
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Lee
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Lee
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul 03080, Korea.; Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul 03080, Korea.
authors.forename: Joon Koo
authors.initials: JK
authors.lastname: Han
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D002417:Cattle; D004566:Electrodes; D066298:In Vitro Techniques; D008099:Liver / Q000473:pathology / Q000601:surgery*; D013552:Swine; D013696:Temperature; D013997:Time Factors
keywords: Bovine; Hepatocellular carcinoma; Minimally invasive; No-touch technique; Preclinical; Radiofrequency ablation