Franz G M Poch1, Christian Rieder2, Hanne Ballhausen2, Verena Knappe3, Jörg-Peter Ritz4, Ole Gemeinhardt1, Martin E Kreis1, Kai S Lehmann1. 1. a Department of General, Visceral and Vascular Surgery , Charité - Campus Benjamin Franklin , Berlin ; 2. b Fraunhofer MEVIS, Institute for Medical Image Computing , Bremen ; 3. c Laser- und Medizin-Technologie GmbH , Berlin ; 4. d Klinik für Allgemein- und Viszeralchirurgie, HELIOS Kliniken Schwerin , Schwerin , Germany.
Abstract
PURPOSE: Major limitations of conventional RFA are vascular cooling effects. However, vascular cooling effects are supposed to be less pronounced in multipolar RFA. The objective of this ex vivo study was a systematic evaluation of the vascular cooling effects in multipolar RFA. MATERIALS AND METHODS: Multipolar RFA with three bipolar RFA applicators was performed ex vivo in porcine liver (applicator distance 20 mm, energy input 40 kJ). A saline-perfused glass tube ('vessel') was placed parallel to the applicators in order to simulate a natural liver vessel. Five applicator-to-vessel geometries were tested. A liquid-filled glass tube without perfusion was used as a dry run. Ablations were orthogonally cut to the applicators at a defined height. Cooling effects were analysed qualitatively and quantitatively along these cross sectional areas. RESULTS: Thirty-six ablations were performed. A cooling effect could be seen in all ablations with perfused vessels compared to the dry run. While this cooling effect did not have any influence on the ablation areas (859-1072 mm(2) versus 958 mm(2) in the dry run, p > 0.05), it had a distinctive impact on ablation shape. A vascular cooling effect could be observed in all ablations with perfusion directly around the vessel independent of the applicator position compared to the dry run (p < 0.01). CONCLUSIONS: A vascular cooling effect occurred in all multipolar RFA with simulated liver vessels ex vivo independent of the applicator-to-vessel geometry. While the cooling effect did not influence the total ablation area, it had a distinctive impact on the ablation shape.
PURPOSE: Major limitations of conventional RFA are vascular cooling effects. However, vascular cooling effects are supposed to be less pronounced in multipolar RFA. The objective of this ex vivo study was a systematic evaluation of the vascular cooling effects in multipolar RFA. MATERIALS AND METHODS: Multipolar RFA with three bipolar RFA applicators was performed ex vivo in porcine liver (applicator distance 20 mm, energy input 40 kJ). A saline-perfused glass tube ('vessel') was placed parallel to the applicators in order to simulate a natural liver vessel. Five applicator-to-vessel geometries were tested. A liquid-filled glass tube without perfusion was used as a dry run. Ablations were orthogonally cut to the applicators at a defined height. Cooling effects were analysed qualitatively and quantitatively along these cross sectional areas. RESULTS: Thirty-six ablations were performed. A cooling effect could be seen in all ablations with perfused vessels compared to the dry run. While this cooling effect did not have any influence on the ablation areas (859-1072 mm(2) versus 958 mm(2) in the dry run, p > 0.05), it had a distinctive impact on ablation shape. A vascular cooling effect could be observed in all ablations with perfusion directly around the vessel independent of the applicator position compared to the dry run (p < 0.01). CONCLUSIONS: A vascular cooling effect occurred in all multipolar RFA with simulated liver vessels ex vivo independent of the applicator-to-vessel geometry. While the cooling effect did not influence the total ablation area, it had a distinctive impact on the ablation shape.
Authors: Franz G M Poch; Christina A Neizert; Ole Gemeinhardt; Beatrice Geyer; Katharina Eminger; Christian Rieder; Stefan M Niehues; Janis Vahldiek; Stefan F Thieme; Kai S Lehmann Journal: Innov Surg Sci Date: 2018-05-11
Authors: C A Neizert; H N C Do; M Zibell; C Rieder; D Sinden; S M Niehues; J L Vahldiek; K S Lehmann; F G M Poch Journal: Sci Rep Date: 2022-10-12 Impact factor: 4.996