title: Microwave ablation of porcine kidneys in vivo: effect of two different ablation modes ("temperature control" and "power control") on procedural outcome.
abstract: OBJECTIVE
  This study was designed to analyze the effect of two different ablation modes ("temperature control" and "power control") of a microwave system on procedural outcome in porcine kidneys in vivo.
  
  
  METHODS
  A commercially available microwave system (Avecure Microwave Generator; MedWaves, San Diego, CA) was used. The system offers the possibility to ablate with two different ablation modes: temperature control and power control. Thirty-two microwave ablations were performed in 16 kidneys of 8 pigs. In each animal, one kidney was ablated twice by applying temperature control (ablation duration set point at 60 s, ablation temperature set point at 96°C, automatic power set point; group I). The other kidney was ablated twice by applying power control (ablation duration set point at 60 s, ablation temperature set point at 96°C, ablation power set point at 24 W; group II). Procedural outcome was analyzed: (1) technical success (e.g., system failures, duration of the ablation cycle), and (2) ablation geometry (e.g., long axis diameter, short axis diameter, and circularity).
  
  
  RESULTS
  System failures occurred in 0% in group I and 13% in group II. Duration of the ablation cycle was 60±0 s in group I and 102±21 s in group II. Long axis diameter was 20.3±4.6 mm in group I and 19.8±3.5 mm in group II (not significant (NS)). Short axis diameter was 10.3±2 mm in group I and 10.5±2.4 mm in group II (NS). Circularity was 0.5±0.1 in group I and 0.5±0.1 in group II (NS).
  
  
  CONCLUSIONS
  Microwave ablations performed with temperature control showed fewer system failures and were finished faster. Both ablation modes demonstrated no significant differences with respect to ablation geometry.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, INF 110, 69120, Heidelberg, Germany. christof.sommer@med.uni-heidelberg.de
authors.forename: C M
authors.initials: CM
authors.lastname: Sommer
authors.forename: F
authors.initials: F
authors.lastname: Arnegger
authors.forename: V
authors.initials: V
authors.lastname: Koch
authors.forename: B
authors.initials: B
authors.lastname: Pap
authors.forename: M
authors.initials: M
authors.lastname: Holzschuh
authors.forename: N
authors.initials: N
authors.lastname: Bellemann
authors.forename: T
authors.initials: T
authors.lastname: Gehrig
authors.forename: J
authors.initials: J
authors.lastname: Senft
authors.forename: F
authors.initials: F
authors.lastname: Nickel
authors.forename: C
authors.initials: C
authors.lastname: Mogler
authors.forename: S
authors.initials: S
authors.lastname: Zelzer
authors.forename: H P
authors.initials: HP
authors.lastname: Meinzer
authors.forename: U
authors.initials: U
authors.lastname: Stampfl
authors.forename: H U
authors.initials: HU
authors.lastname: Kauczor
authors.forename: B A
authors.initials: BA
authors.lastname: Radeleff
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D007668:Kidney / Q000601:surgery*; D008872:Microwaves / Q000627:therapeutic use*; D023421:Models, Animal; D009392:Nephrectomy / Q000295:instrumentation / Q000379:methods*; D013552:Swine; D013696:Temperature