title: Sequential activation of ground pads reduces skin heating during radiofrequency ablation: initial in vivo porcine results.
abstract: OBJECTIVE
  Radiofrequency (RF) ablation is a common treatment modality for inoperable liver cancer. Skin burns below ground pads during RF ablations are increasingly prevalent, hindering the development of higher-power RF generators capable of creating larger ablation zones.
  
  
  METHODS
  9 RF ablations (n=4 simultaneous, n=5 sequential) were performed with 300 W for 12 min via two internally cooled cluster electrodes placed in the gluteus maximus of domestic swine. Three ground pads placed on the animal's abdomen were activated either simultaneously, or sequentially where activation timing was adjusted to equilibrate skin temperature below each pad. Temperature rise at each pad was compared. Ablation zone dimensions were determined via MRI.
  
  
  RESULTS
  Maximum temperature rise was significantly higher with simultaneous activation than with sequential activation (21.4 vs 8.1 degress C, p<0.01). Ablation zone diameters during simultaneous and sequential activation were 6.9+/-0.3 and 5.6+/-0.3, respectively.
  
  
  CONCLUSIONS
  Sequential activation of multiple ground pads resulted in significantly lower skin temperatures during highpower RF ablation.
authors: Medical University of South Carolina, Charleston, SC 29425, USA.
authors: David J
authors: DJ
authors: Schutt
authors: M Michael
authors: MM
authors: Swindle
authors: Gorka A
authors: GA
authors: Bastarrika
authors: Dieter
authors: D
authors: Haemmerich
mesh_terms: D000465:Algorithms; D000818:Animals; D001703:Biophysics; D001831:Body Temperature; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D004594:Electrophysiology / Q000379:methods; D004867:Equipment Design; D008279:Magnetic Resonance Imaging / Q000379:methods; D019047:Phantoms, Imaging; D011846:Radio Waves; D012867:Skin / Q000473:pathology*; D013552:Swine; D013696:Temperature; D013997:Time Factors