title: Postbiopsy bleeding in a porcine model: reduction with radio-frequency ablation--preliminary results.
abstract: OBJECTIVE
  To test a biopsy needle modified for use of radio-frequency (RF) energy to produce hemostasis after core biopsy of liver or kidney.
  
  
  METHODS
  RF energy was applied to a partially insulated 17-gauge needle, and tip temperature was monitored with a thermocouple. Domestic Yorkshire pigs (n = 4; mean weight, 23.4 kg) were anesthetized, and their livers and kidneys were exposed. Needles were inserted 2 cm into hepatic and renal parenchyma and retracted, either with or without tract ablation to 65 degrees C, in normal tissue, animals treated with anticoagulants, and an animal with acute inferior vena caval occlusion to produce portal hypertension. Blood loss was assessed by weighing surgical sponges with blood from the puncture sites. Significant differences in blood loss between control and ablated biopsy specimens in each scenario were tested by using a Wilcoxon matched-pairs signed rank test.
  
  
  RESULTS
  Mean blood loss for each group was as follows: In the liver, control biopsy specimens (n = 18) lost 0.30 g while ablated biopsy specimens lost 0.00044 g (P <.01), and control biopsy specimens treated with heparin (n = 26) lost 0.45 g while biopsy specimens treated with heparin and ablation lost 0.27 g (P =.03). For inferior vena caval occlusion, control biopsy specimens lost 1.23 g, while ablated biopsy specimens lost 0.00 g. In the kidney, control biopsy specimens (n = 28) lost 0.82 g, while ablated biopsy specimens lost 0.24 g (P =.01), and control biopsy specimens treated with heparin (n = 14) lost 1.04 g, while biopsy specimens treated with heparin and ablation lost 0.19 g (P =.02).
  
  
  CONCLUSIONS
  Tract ablation with thermocouple-monitored RF energy decreased postprocedural hemorrhage after hepatic and renal biopsy.
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison Medical School, CSC-Module E3-311, Box 3252, 600 Highland Ave, 53792, USA.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Laeseke
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Winter
authors.forename: Connie L
authors.initials: CL
authors.lastname: Davis
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Stevens
authors.forename: Chris D
authors.initials: CD
authors.lastname: Johnson
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Fronczak
authors.forename: John G
authors.initials: JG
authors.lastname: Webster
authors.forename: Fred T
authors.initials: FT
authors.lastname: Lee
mesh_terms: D000818:Animals; D001707:Biopsy, Needle / Q000009:adverse effects*; D017115:Catheter Ablation / Q000009:adverse effects*; D004195:Disease Models, Animal; D005260:Female; D006489:Hemostatic Techniques; D019106:Postoperative Hemorrhage / Q000517:prevention & control*; D013552:Swine