title: Radiofrequency ablation at low irrigation flow rates using a novel 12-hole gold open-irrigation catheter.
abstract: BACKGROUND
  High irrigation rates during radiofrequency (RF) ablation may cause fluid overload and limit lesion size. This in vivo animal study assessed the safety and efficacy of RF ablation at low irrigation rates using a novel 12-hole gold catheter.
  
  
  METHODS
  A total of 103 lesions, created on the thigh of five mongrel dogs, were analyzed. Lesions were created using a 12-hole irrigated gold-tip (Au) and a six-hole irrigated platinum-iridium (PtIr) catheter (both 7F/3.5-mm electrode; BIOTRONIK SE & CO, KG, Berlin, Germany) in parallel and perpendicular orientation. RF current was delivered for 60 seconds at 30 W using 8 mL/min and 15 mL/min irrigation. Electrode temperature, steam pops, lesion dimensions, and coagulum formation were recorded.
  
  
  RESULTS
  Electrode temperatures were lower for Au compared to PtIr in parallel (8 mL/min: 38.1 ± 1.7°C vs 48.0 ± 4.8°C, P < 0.0001; 15 mL/min: 36.0 ± 1.5°C vs 46.9 ± 5.4°C, P < 0.0001) and perpendicular position (15 mL/min: 35.5 ± 1.2°C vs 38.4 ± 2.5°C, P = 0.003). The number of steam pops between Au and PtIr was comparable for parallel (8 mL/min: 14% vs 27%, P = 0.65; 15 mL/min: 14% vs 43%, P = 0.21) and perpendicular orientation (8 mL/min: 25% vs 17%, P = 1.00; 15 mL/min: 18% vs 0%, P = 0.48). Au created larger volumes than PtIr at 8 mL/min irrigation (861 ± 251 mm(3) vs 504 ± 212 mm(3) , P = 0.004); however, for 15 mL/min, volumes were comparable (624 ± 269 mm(3) vs 768 ± 466 mm(3) , P = 0.46). No coagulum formation was observed for any of the catheters on the surface and catheter tip.
  
  
  CONCLUSIONS
  RF ablation at low flow rate using a novel 12-hole irrigation Au catheter is safe and results in larger lesions than with a PtIr electrode.
authors.affiliation: Department of Electrophysiology, Erasmus Medical Center, Rotterdam, the Netherlands.
authors.forename: Ferdi
authors.initials: F
authors.lastname: Akca
authors.forename: Endre
authors.initials: E
authors.lastname: Zima
authors.forename: Eszter M
authors.initials: EM
authors.lastname: Végh
authors.forename: Gábor
authors.initials: G
authors.lastname: Széplaki
authors.forename: Judit
authors.initials: J
authors.lastname: Skopál
authors.forename: Martha
authors.initials: M
authors.lastname: Hubay
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Lendvai
authors.forename: Bela
authors.initials: B
authors.lastname: Merkely
authors.forename: Tamas
authors.initials: T
authors.lastname: Szili-Torok
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods*; D004285:Dogs; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold; D018482:Muscle, Skeletal / Q000166:cytology* / Q000601:surgery*; D012212:Rheology / Q000295:instrumentation / Q000379:methods; D007507:Therapeutic Irrigation / Q000295:instrumentation* / Q000379:methods*
chemical_list: D006046:Gold
keywords: catheter ablation; electrophysiology; gold-tip electrode; irrigated-tip catheter; lesions