title: A trucut biopsy needle for bipolar radiofrequency ablation of needle tract: a proof-of-concept experiment.
abstract: OBJECTIVE
  To develop a trucut biopsy needle featuring two electrodes that allow for bipolar radiofrequency (RF) coagulation of the puncture tract.
  
  
  METHODS
  We modified a 14-G trucut biopsy needle to contain two insulated electrodes and connected the device to an RF generator. Biopsies in ex vivo porcine liver and kidney were performed. The puncture tract was coagulated by using different RF energy settings (5 W, 10 W, 20 W). Tissue specimens were dissected along the puncture tract and the coagulation area was macroscopically evaluated. CT-guided in vivo liver and kidney biopsies were performed in two domestic pigs. Lengths of specimens were measured. Post-biopsy contrast-enhanced CT examinations were performed to rule out biopsy-related bleeding. Animals were euthanised and coagulation areas macroscopically explored.
  
  
  RESULTS
  The mean diameters of the coagulated area around the ex vivo biopsy tract were 4.2 +/- 1.1 mm (5 W), 6.0 +/- 2.0 mm (10 W) and 5.2 +/- 0.51 mm (20 W) in liver and 5.0 +/- 0.7 mm (5 W), 6.6 +/- 0.9 (10 W) and 6.0 +/- 2.0 mm (20 W) in kidney. After biopsies CT revealed no bleeding. Mean maximum coagulation diameters were 10.1 +/- 4.6 mm (10 W) in liver and 6.0 +/- 2.5 mm (10 W) in kidney. Mean length of the specimens was 12.2 +/- 4.4 mm in kidney and 11.1 +/- 3.6 mm in liver tissue.
  
  
  CONCLUSIONS
  Bipolar RF biopsy is a promising tool for tract coagulation after percutaneous biopsy.
authors.affiliation: Applied Medical Engineering, Helmholtz Institute for Biomedical Engineering, RWTH Aachen University, Aachen, Germany. bruners@rad.rwth-aachen.de
authors.forename: Philipp
authors.initials: P
authors.lastname: Bruners
authors.forename: Tobias
authors.initials: T
authors.lastname: Penzkofer
authors.forename: Peter
authors.initials: P
authors.lastname: Isfort
authors.forename: Jochen
authors.initials: J
authors.lastname: Pfeffer
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmitz-Rode
authors.forename: Rolf W
authors.initials: RW
authors.lastname: Günther
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Mahnken
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation*; D004285:Dogs; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007668:Kidney / Q000000981:diagnostic imaging / Q000473:pathology*; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology*; D009339:Needles; D010865:Pilot Projects; D011677:Punctures / Q000295:instrumentation*; D011859:Radiography