title: Cellular and vascular reactions in the liver to radio-frequency thermo-ablation with wet needle applicators. Study on juvenile domestic pigs.
abstract: The aim of this animal experiment was to investigate the cellular and vascular reactions in the liver of juvenile domestic pigs produced by a radio-frequency thermoablation (RFTA) applicator perfused with saline solution.
  
  
  METHODS
  A total of 13 coagulation necroses were produced in the liver of 3 anesthetized domestic pigs using RFTA. The pigs were dissected and the coagulations examined.
  
  
  RESULTS
  The mean macroscopical length and width of the coagulation zones with a hemorrhagic marginal zone after a 5-minute application time were 34.1 +/- 8 mm (22-46 mm) and 20.8 +/- 4 mm (12 +/- 28 mm) respectively. The sonographically determined diameters correlated significantly (r(length) = 0.741 and r(width) = 0.923). Three areas in the coagulation zones could be histologically distinguished: (1) central necrosis zone, (2) hemorrhagic marginal zone, (3) sublethal damage zone. Large vessels did not show any substantial changes after RFTA. Venous vessels less than 1 mm were completely thermally denatured or destroyed.
  
  
  CONCLUSIONS
  Tumors in close proximity to large blood vessels can be treated by RFTA with 'wet electrodes'.
mesh_terms: D000818:Animals; D001652:Bile Ducts / Q000473:pathology; D017115:Catheter Ablation / Q000379:methods*; D006503:Hepatic Veins / Q000473:pathology; D008099:Liver / Q000098:blood supply / Q000473:pathology* / Q000601:surgery*; D008102:Liver Circulation; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D009336:Necrosis; D009339:Needles; D034421:Sus scrofa; D013927:Thrombosis / Q000473:pathology