title: Safety and efficacy of high-intensity focused ultrasound atop coronary arteries during epicardial catheter ablation.
abstract: BACKGROUND
  Coronary arterial injury continues to be a limitation of epicardial catheter ablation using currently available energy sources. Application of high intensity focused ultrasound (HIFU) energy may avoid such injury due to its theoretical ability to focus energy beyond the ablation element and create lesions at depth.
  
  
  OBJECTIVE
  This study evaluated the safety of HIFU applications delivered directly over the left anterior descending (LAD) artery in an open-chest swine model.
  
  
  METHODS
  Ten swine underwent median sternotomy. A prototype HIFU probe was placed atop the LAD. Forty-three therapies along the LAD (60-seconds/6 watt) were analyzed. Three, 3, and 4 swine were studied at 2, 4, and 8 weeks and subsequently sacrificed. Lesions were scored (0-4) depending on the percent circumferential involvement of arteries.
  
  
  RESULTS
  Lesion area increased minimally from 54.5 ± 18.0 mm(2) at 2 weeks to 56.9 ± 20.6 mm(2) at 8 weeks, and depth increased moderately from 13.2 ± 2.5 mm to 15.5 ± 3.4 mm. At 2, 4, and 8 weeks, the mean injury score of the LAD was 0.8 ± 0.3, 1.5 ± 0.9, and 2.0 ± 0.7. No/minimal arterial injury was seen in 64% of all sections. However, a progressive increase in injury resulted in 89% of all sections showing any injury at 8 weeks. One animal developed occlusion of the distal LAD.
  
  
  CONCLUSIONS
  HIFU has the potential to create deep ventricular lesions with relative sparing of the LAD. The incremental arterial damage noted over time warrants further evaluation to support the viability of focusing ultrasound energy beyond vulnerable critical structures to ablate deeper targets.
authors.affiliation: Helmsley Cardiac Arrhythmia Service, Mount Sinai Medical Center, New York, New York, USA.
authors.forename: Jacob S
authors.initials: JS
authors.lastname: Koruth
authors.forename: Srinivas
authors.initials: S
authors.lastname: Dukkipati
authors.forename: Roger G
authors.initials: RG
authors.lastname: Carrillo
authors.forename: James
authors.initials: J
authors.lastname: Coffey
authors.forename: Jennifer
authors.initials: J
authors.lastname: Teng
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Eby
authors.forename: Vivek Y
authors.initials: VY
authors.lastname: Reddy
authors.forename: Andre
authors.initials: A
authors.lastname: D'Avila
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000009:adverse effects / Q000295:instrumentation; D057785:Catheters; D003331:Coronary Vessels / Q000293:injuries / Q000473:pathology; D004867:Equipment Design; D006335:Heart Injuries / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D057086:High-Intensity Focused Ultrasound Ablation / Q000009:adverse effects / Q000295:instrumentation; D023421:Models, Animal; D009206:Myocardium / Q000473:pathology; D010496:Pericardium / Q000601:surgery*; D056346:Sternotomy; D013552:Swine; D013997:Time Factors; D057772:Vascular System Injuries / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*