title: Evaluation of a novel high-intensity focused ultrasound device: preclinical studies in a porcine model.
abstract: BACKGROUND
  High-intensity focused ultrasound (HIFU) has been applied clinically for the noninvasive treatment of pathological conditions in various organs for over 50 years; however, there are little data describing the use of thermal HIFU to ablate fat for body contouring and treatment of collagen-rich layers. A novel device under clinical investigation (LipoSonix; Medicis Technologies Corporation, Bothell, Washington) uses HIFU to eliminate unwanted adipose tissue.
  
  
  OBJECTIVE
  The authors describe the results of HIFU treatment in a series of preclinical studies performed in a validated porcine model.
  
  
  METHODS
  Preclinical research included in vivo treatment of the abdominal subcutaneous adipose tissue of swine with transcutaneous HIFU therapy. Endpoint analyses included thermocouple temperature data, full-body necropsy, local pathology and histology studies, clinical hematology, urinalysis, and blood chemistry parameters, including lipid panels.
  
  
  RESULTS
  The application of HIFU energy levels of 166 to 372 J/cm(2) generated tissue temperature approaching 70°C, which was restricted to the focal area (n = seven). Application of 68 and 86 J/cm(2) did not produce clinically-significant changes in serum liver function tests, free fatty acids, or cholesterol (n = eight). Gross examination of tissue from various organs showed no evidence of fat emboli or accumulation (n = two). Histology demonstrated well-preserved vasculature and intact nerve fibers within the HIFU focal area (n = three). Following treatment with 85.3 to 270 J/cm(2), normal healing response included the migration of macrophages into the damaged tissue and removal of disrupted cellular debris and lipids (n = 8).
  
  
  CONCLUSIONS
  In a preclinical swine model, the controlled thermal effect of HIFU appears to provide a safe and effective means for ablating subcutaneous adipose tissue.
authors.affiliation: Oregon Health Sciences University, Eugene, Oregon 97401,USA. mjewell@teleport.com
authors.forename: Mark L
authors.initials: ML
authors.lastname: Jewell
authors.forename: Charles
authors.initials: C
authors.lastname: Desilets
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Smoller
mesh_terms: D000818:Animals; D001831:Body Temperature; D003357:Cosmetic Techniques; D004195:Disease Models, Animal; D057086:High-Intensity Focused Ultrasound Ablation / Q000379:methods*; D050356:Lipid Metabolism; D008264:Macrophages / Q000378:metabolism; D050151:Subcutaneous Fat / Q000000981:diagnostic imaging*; D013552:Swine; D014463:Ultrasonography