title: Comparison of endocardial and epicardial lesion size following large-tip and extra-large-tip transcatheter cryoablation.
abstract: BACKGROUND
  The efficacy of transcatheter cryoablation for ventricular tachycardia (VT) remains controversial because of the limited size of the lesion produced. An increased lesion size if the cryoablation catheter profile and catheter tip length were increased was hypothesized.
  
  
  RESULTS
  Closed-chest transcatheter cryoablation was applied with 7F, 6-mm tip (n=11, 7F group) and 9F, 8-mm tip (n=8, 9F group) catheters to the left ventricular (LV) endocardium and epicardium. Catheter-tip temperature was set to -70 to -80 degrees C, and cryoablation duration was set to 240 s. In acute experiments in the 7F group, endocardial lesion volume was 144.1 +/-86.0 mm(3) and lesion depth was 5.1 +/-1.6 mm, and epicardial lesion volume was 205.6 +/-157.8 mm(3) and lesion depth was 4.7 +/-2.2 mm. In the 9F group, endocardial lesion volume was 301.5 +/-177.4 mm(3) (P<0.001 vs 7F group) and lesion depth was 8.4 +/-1.9 mm (P<0.001 vs 7F group), and epicardial lesion volume was 375.3 +/-167.6 mm(3) (P<0.01 vs 7F group) and lesion depth was 5.0 +/-2.3 mm.
  
  
  CONCLUSIONS
  Transcatheter cryoablation of the LV endocardium and epicardium using a larger profile and longer tip electrode may be useful for treating VT originating from the midmyocardium or epicardium.
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Ichiro
authors.initials: I
authors.lastname: Watanabe
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Okumura
authors.forename: Kimie
authors.initials: K
authors.lastname: Ohkubo
authors.forename: Sonoko
authors.initials: S
authors.lastname: Ashino
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kofune
authors.forename: Toshiko
authors.initials: T
authors.lastname: Nakai
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kunimoto
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kasamaki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hirayama
mesh_terms: D000818:Animals; D006328:Cardiac Catheterization / Q000009:adverse effects / Q000295:instrumentation*; D003452:Cryosurgery / Q000009:adverse effects / Q000295:instrumentation*; D004285:Dogs; D004699:Endocardium / Q000473:pathology / Q000601:surgery*; D004867:Equipment Design; D006352:Heart Ventricles / Q000473:pathology / Q000601:surgery*; D023421:Models, Animal; D009336:Necrosis; D010496:Pericardium / Q000473:pathology / Q000601:surgery*; D013552:Swine; D013997:Time Factors